File:  [LON-CAPA] / loncom / interface / lonnavmaps.pm
Revision 1.431: download - view: text, annotated - select for diffs
Mon Mar 16 15:25:40 2009 UTC (15 years, 3 months ago) by schulted
Branches: MAIN
CVS tags: HEAD
Realized the sort function on change of the drop-down menu without the "Sort by:"-button, because of ergonomic reasons.
Added text as a description for the toolbar.

    1: # The LearningOnline Network with CAPA
    2: # Navigate Maps Handler
    3: #
    4: # $Id: lonnavmaps.pm,v 1.431 2009/03/16 15:25:40 schulted Exp $
    5: #
    6: # Copyright Michigan State University Board of Trustees
    7: #
    8: # This file is part of the LearningOnline Network with CAPA (LON-CAPA).
    9: #
   10: # LON-CAPA is free software; you can redistribute it and/or modify
   11: # it under the terms of the GNU General Public License as published by
   12: # the Free Software Foundation; either version 2 of the License, or
   13: # (at your option) any later version.
   14: #
   15: # LON-CAPA is distributed in the hope that it will be useful,
   16: # but WITHOUT ANY WARRANTY; without even the implied warranty of
   17: # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   18: # GNU General Public License for more details.
   19: #
   20: # You should have received a copy of the GNU General Public License
   21: # along with LON-CAPA; if not, write to the Free Software
   22: # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   23: #
   24: # /home/httpd/html/adm/gpl.txt
   25: #
   26: # http://www.lon-capa.org/
   27: #
   28: ###
   29: 
   30: =pod
   31: 
   32: =head1 NAME
   33: 
   34: Apache::lonnavmaps.pm
   35: 
   36: =head1 SYNOPSIS
   37: 
   38: Handles navigational maps.
   39: 
   40: The main handler generates the navigational listing for the course,
   41: the other objects export this information in a usable fashion for
   42: other modules.
   43: 
   44: 
   45: This is part of the LearningOnline Network with CAPA project
   46: described at http://www.lon-capa.org.
   47: 
   48: 
   49: =head1 OVERVIEW
   50: 
   51: X<lonnavmaps, overview> When a user enters a course, LON-CAPA examines the
   52: course structure and caches it in what is often referred to as the
   53: "big hash" X<big hash>. You can see it if you are logged into
   54: LON-CAPA, in a course, by going to /adm/test. (You may need to
   55: tweak the /home/httpd/lonTabs/htpasswd file to view it.) The
   56: content of the hash will be under the heading "Big Hash".
   57: 
   58: Big Hash contains, among other things, how resources are related
   59: to each other (next/previous), what resources are maps, which 
   60: resources are being chosen to not show to the student (for random
   61: selection), and a lot of other things that can take a lot of time
   62: to compute due to the amount of data that needs to be collected and
   63: processed.
   64: 
   65: Apache::lonnavmaps provides an object model for manipulating this
   66: information in a higher-level fashion than directly manipulating 
   67: the hash. It also provides access to several auxilary functions 
   68: that aren't necessarily stored in the Big Hash, but are a per-
   69: resource sort of value, like whether there is any feedback on 
   70: a given resource.
   71: 
   72: Apache::lonnavmaps also abstracts away branching, and someday, 
   73: conditions, for the times where you don't really care about those
   74: things.
   75: 
   76: Apache::lonnavmaps also provides fairly powerful routines for
   77: rendering navmaps, and last but not least, provides the navmaps
   78: view for when the user clicks the NAV button.
   79: 
   80: B<Note>: Apache::lonnavmaps I<only> works for the "currently
   81: logged in user"; if you want things like "due dates for another
   82: student" lonnavmaps can not directly retrieve information like
   83: that. You need the EXT function. This module can still help,
   84: because many things, such as the course structure, are constant
   85: between users, and Apache::lonnavmaps can help by providing
   86: symbs for the EXT call.
   87: 
   88: The rest of this file will cover the provided rendering routines, 
   89: which can often be used without fiddling with the navmap object at
   90: all, then documents the Apache::lonnavmaps::navmap object, which
   91: is the key to accessing the Big Hash information, covers the use
   92: of the Iterator (which provides the logic for traversing the 
   93: somewhat-complicated Big Hash data structure), documents the
   94: Apache::lonnavmaps::Resource objects that are returned by 
   95: 
   96: =head1 Subroutine: render
   97: 
   98: The navmap renderer package provides a sophisticated rendering of the
   99: standard navigation maps interface into HTML. The provided nav map
  100: handler is actually just a glorified call to this.
  101: 
  102: Because of the large number of parameters this function accepts,
  103: instead of passing it arguments as is normal, pass it in an anonymous
  104: hash with the desired options.
  105: 
  106: The package provides a function called 'render', called as
  107: Apache::lonnavmaps::render({}).
  108: 
  109: =head2 Overview of Columns
  110: 
  111: The renderer will build an HTML table for the navmap and return
  112: it. The table consists of several columns, and a row for each
  113: resource (or possibly each part). You tell the renderer how many
  114: columns to create and what to place in each column, optionally using
  115: one or more of the prepared columns, and the renderer will assemble
  116: the table.
  117: 
  118: Any additional generally useful column types should be placed in the
  119: renderer code here, so anybody can use it anywhere else. Any code
  120: specific to the current application (such as the addition of <input>
  121: elements in a column) should be placed in the code of the thing using
  122: the renderer.
  123: 
  124: At the core of the renderer is the array reference COLS (see Example
  125: section below for how to pass this correctly). The COLS array will
  126: consist of entries of one of two types of things: Either an integer
  127: representing one of the pre-packaged column types, or a sub reference
  128: that takes a resource reference, a part number, and a reference to the
  129: argument hash passed to the renderer, and returns a string that will
  130: be inserted into the HTML representation as it.
  131: 
  132: All other parameters are ways of either changing how the columns
  133: are printing, or which rows are shown.
  134: 
  135: The pre-packaged column names are refered to by constants in the
  136: Apache::lonnavmaps namespace. The following currently exist:
  137: 
  138: =over 4
  139: 
  140: =item * B<Apache::lonnavmaps::resource>:
  141: 
  142: The general info about the resource: Link, icon for the type, etc. The
  143: first column in the standard nav map display. This column provides the
  144: indentation effect seen in the B<NAV> screen. This column also accepts
  145: the following parameters in the renderer hash:
  146: 
  147: =over 4
  148: 
  149: =item * B<resource_nolink>: default false
  150: 
  151: If true, the resource will not be linked. By default, all non-folder
  152: resources are linked.
  153: 
  154: =item * B<resource_part_count>: default true
  155: 
  156: If true, the resource will show a part count B<if> the full
  157: part list is not displayed. (See "condense_parts" later.) If false,
  158: the resource will never show a part count.
  159: 
  160: =item * B<resource_no_folder_link>:
  161: 
  162: If true, the resource's folder will not be clickable to open or close
  163: it. Default is false. True implies printCloseAll is false, since you
  164: can't close or open folders when this is on anyhow.
  165: 
  166: =back
  167: 
  168: =item * B<Apache::lonnavmaps::communication_status>:
  169: 
  170: Whether there is discussion on the resource, email for the user, or
  171: (lumped in here) perl errors in the execution of the problem. This is
  172: the second column in the main nav map.
  173: 
  174: =item * B<Apache::lonnavmaps::quick_status>:
  175: 
  176: An icon for the status of a problem, with five possible states:
  177: Correct, incorrect, open, awaiting grading (for a problem where the
  178: computer's grade is suppressed, or the computer can't grade, like
  179: essay problem), or none (not open yet, not a problem). The
  180: third column of the standard navmap.
  181: 
  182: =item * B<Apache::lonnavmaps::long_status>:
  183: 
  184: A text readout of the details of the current status of the problem,
  185: such as "Due in 22 hours". The fourth column of the standard navmap.
  186: 
  187: =item * B<Apache::lonnavmaps::part_status_summary>:
  188: 
  189: A text readout summarizing the status of the problem. If it is a
  190: single part problem, will display "Correct", "Incorrect", 
  191: "Not yet open", "Open", "Attempted", or "Error". If there are
  192: multiple parts, this will output a string that in HTML will show a
  193: status of how many parts are in each status, in color coding, trying
  194: to match the colors of the icons within reason.
  195: 
  196: Note this only makes sense if you are I<not> showing parts. If 
  197: C<showParts> is true (see below), this column will not output
  198: anything. 
  199: 
  200: =back
  201: 
  202: If you add any others please be sure to document them here.
  203: 
  204: An example of a column renderer that will show the ID number of a
  205: resource, along with the part name if any:
  206: 
  207:  sub { 
  208:   my ($resource, $part, $params) = @_;   
  209:   if ($part) { return '<td>' . $resource->{ID} . ' ' . $part . '</td>'; }
  210:   return '<td>' . $resource->{ID} . '</td>';
  211:  }
  212: 
  213: Note these functions are responsible for the TD tags, which allow them
  214: to override vertical and horizontal alignment, etc.
  215: 
  216: =head2 Parameters
  217: 
  218: Minimally, you should be
  219: able to get away with just using 'cols' (to specify the columns
  220: shown), 'url' (necessary for the folders to link to the current screen
  221: correctly), and possibly 'queryString' if your app calls for it. In
  222: that case, maintaining the state of the folders will be done
  223: automatically.
  224: 
  225: =over 4
  226: 
  227: =item * B<iterator>: default: constructs one from %env
  228: 
  229: A reference to a fresh ::iterator to use from the navmaps. The
  230: rendering will reflect the options passed to the iterator, so you can
  231: use that to just render a certain part of the course, if you like. If
  232: one is not passed, the renderer will attempt to construct one from
  233: env{'form.filter'} and env{'form.condition'} information, plus the
  234: 'iterator_map' parameter if any.
  235: 
  236: =item * B<iterator_map>: default: not used
  237: 
  238: If you are letting the renderer do the iterator handling, you can
  239: instruct the renderer to render only a particular map by passing it
  240: the source of the map you want to process, like
  241: '/res/103/jerf/navmap.course.sequence'.
  242: 
  243: =item * B<include_top_level_map>: default: false
  244: 
  245: If you need to include the top level map (meaning the course) in the
  246: rendered output set this to true
  247: 
  248: =item * B<navmap>: default: constructs one from %env
  249: 
  250: A reference to a navmap, used only if an iterator is not passed in. If
  251: this is necessary to make an iterator but it is not passed in, a new
  252: one will be constructed based on env info. This is useful to do basic
  253: error checking before passing it off to render.
  254: 
  255: =item * B<r>: default: must be passed in
  256: 
  257: The standard Apache response object. This must be passed to the
  258: renderer or the course hash will be locked.
  259: 
  260: =item * B<cols>: default: empty (useless)
  261: 
  262: An array reference
  263: 
  264: =item * B<showParts>:default true
  265: 
  266: A flag. If true, a line for the resource itself, and a line
  267: for each part will be displayed. If not, only one line for each
  268: resource will be displayed.
  269: 
  270: =item * B<condenseParts>: default true
  271: 
  272: A flag. If true, if all parts of the problem have the same
  273: status and that status is Nothing Set, Correct, or Network Failure,
  274: then only one line will be displayed for that resource anyhow. If no,
  275: all parts will always be displayed. If showParts is 0, this is
  276: ignored.
  277: 
  278: =item * B<jumpCount>: default: determined from %env
  279: 
  280: A string identifying the URL to place the anchor 'curloc' at.
  281: It is the responsibility of the renderer user to
  282: ensure that the #curloc is in the URL. By default, determined through
  283: the use of the env{} 'jump' information, and should normally "just
  284: work" correctly.
  285: 
  286: =item * B<here>: default: empty string
  287: 
  288: A Symb identifying where to place the 'here' marker. The empty
  289: string means no marker.
  290: 
  291: =item * B<indentString>: default: 25 pixel whitespace image
  292: 
  293: A string identifying the indentation string to use. 
  294: 
  295: =item * B<queryString>: default: empty
  296: 
  297: A string which will be prepended to the query string used when the
  298: folders are opened or closed. You can use this to pass
  299: application-specific values.
  300: 
  301: =item * B<url>: default: none
  302: 
  303: The url the folders will link to, which should be the current
  304: page. Required if the resource info column is shown, and you 
  305: are allowing the user to open and close folders.
  306: 
  307: =item * B<currentJumpIndex>: default: no jumping
  308: 
  309: Describes the currently-open row number to cause the browser to jump
  310: to, because the user just opened that folder. By default, pulled from
  311: the Jump information in the env{'form.*'}.
  312: 
  313: =item * B<printKey>: default: false
  314: 
  315: If true, print the key that appears on the top of the standard
  316: navmaps.
  317: 
  318: =item * B<printCloseAll>: default: true
  319: 
  320: If true, print the "Close all folders" or "open all folders"
  321: links.
  322: 
  323: =item * B<filterFunc>: default: sub {return 1;} (accept everything)
  324: 
  325: A function that takes the resource object as its only parameter and
  326: returns a true or false value. If true, the resource is displayed. If
  327: false, it is simply skipped in the display.
  328: 
  329: =item * B<suppressEmptySequences>: default: false
  330: 
  331: If you're using a filter function, and displaying sequences to orient
  332: the user, then frequently some sequences will be empty. Setting this to
  333: true will cause those sequences not to display, so as not to confuse the
  334: user into thinking that if the sequence is there there should be things
  335: under it; for example, see the "Show Uncompleted Homework" view on the
  336: B<NAV> screen.
  337: 
  338: =item * B<suppressNavmaps>: default: false
  339: 
  340: If true, will not display Navigate Content resources. 
  341: 
  342: =back
  343: 
  344: =head2 Additional Info
  345: 
  346: In addition to the parameters you can pass to the renderer, which will
  347: be passed through unchange to the column renderers, the renderer will
  348: generate the following information which your renderer may find
  349: useful:
  350: 
  351: =over 4
  352: 
  353: =item * B<counter>: 
  354: 
  355: Contains the number of rows printed. Useful after calling the render 
  356: function, as you can detect whether anything was printed at all.
  357: 
  358: =item * B<isNewBranch>:
  359: 
  360: Useful for renderers: If this resource is currently the first resource
  361: of a new branch, this will be true. The Resource column (leftmost in the
  362: navmaps screen) uses this to display the "new branch" icon 
  363: 
  364: =back
  365: 
  366: =cut
  367: 
  368: 
  369: =head1 SUBROUTINES
  370: 
  371: =over
  372: 
  373: =item update()
  374: 
  375: =item addToFilter()
  376: 
  377: Convenience functions: Returns a string that adds or subtracts
  378: the second argument from the first hash, appropriate for the 
  379: query string that determines which folders to recurse on
  380: 
  381: =item removeFromFilter()
  382: 
  383: =item getLinkForResource()
  384: 
  385: Convenience function: Given a stack returned from getStack on the iterator,
  386: return the correct src() value.
  387: 
  388: =item getDescription()
  389: 
  390: Convenience function: This separates the logic of how to create
  391: the problem text strings ("Due: DATE", "Open: DATE", "Not yet assigned",
  392: etc.) into a separate function. It takes a resource object as the
  393: first parameter, and the part number of the resource as the second.
  394: It's basically a big switch statement on the status of the resource.
  395: 
  396: =item dueInLessThan24Hours()
  397: 
  398: Convenience function, so others can use it: Is the problem due in less than 24 hours, and still can be done?
  399: 
  400: =item lastTry()
  401: 
  402: Convenience function, so others can use it: Is there only one try remaining for the
  403: part, with more than one try to begin with, not due yet and still can be done?
  404: 
  405: =item advancedUser()
  406: 
  407: This puts a human-readable name on the env variable.
  408: 
  409: =item timeToHumanString()
  410: 
  411: timeToHumanString takes a time number and converts it to a
  412: human-readable representation, meant to be used in the following
  413: manner:
  414: 
  415: =over 4
  416: 
  417: =item * print "Due $timestring"
  418: 
  419: =item * print "Open $timestring"
  420: 
  421: =item * print "Answer available $timestring"
  422: 
  423: =back
  424: 
  425: Very, very, very, VERY English-only... goodness help a localizer on
  426: this func...
  427: 
  428: =item resource()
  429: 
  430: returns 0
  431: 
  432: =item communication_status()
  433: 
  434: returns 1
  435: 
  436: =item quick_status()
  437: 
  438: returns 2
  439: 
  440: =item long_status()
  441: 
  442: returns 3
  443: 
  444: =item part_status_summary()
  445: 
  446: returns 4
  447: 
  448: =item render_resource()
  449: 
  450: =item render_communication_status()
  451: 
  452: =item render_quick_status()
  453: 
  454: =item render_long_status()
  455: 
  456: =item render_parts_summary_status()
  457: 
  458: =item setDefault()
  459: 
  460: =item cmp_title()
  461: 
  462: =item render()
  463: 
  464: =item add_linkitem()
  465: 
  466: =item show_linkitems()
  467: 
  468: =back
  469: 
  470: =cut
  471: 
  472: package Apache::lonnavmaps;
  473: 
  474: use strict;
  475: use GDBM_File;
  476: use Apache::loncommon();
  477: use Apache::lonenc();
  478: use Apache::lonlocal;
  479: use Apache::lonnet;
  480: use POSIX qw (floor strftime);
  481: use Time::HiRes qw( gettimeofday tv_interval );
  482: use LONCAPA;
  483: use DateTime();
  484: 
  485: # symbolic constants
  486: sub SYMB { return 1; }
  487: sub URL { return 2; }
  488: sub NOTHING { return 3; }
  489: 
  490: # Some data
  491: 
  492: my $resObj = "Apache::lonnavmaps::resource";
  493: 
  494: # Keep these mappings in sync with lonquickgrades, which uses the colors
  495: # instead of the icons.
  496: my %statusIconMap = 
  497:     (
  498:      $resObj->CLOSED       => '',
  499:      $resObj->OPEN         => 'navmap.open.gif',
  500:      $resObj->CORRECT      => 'navmap.correct.gif',
  501:      $resObj->PARTIALLY_CORRECT      => 'navmap.partial.gif',
  502:      $resObj->INCORRECT    => 'navmap.wrong.gif',
  503:      $resObj->ATTEMPTED    => 'navmap.ellipsis.gif',
  504:      $resObj->ERROR        => ''
  505:      );
  506: 
  507: my %iconAltTags = 
  508:     ( 'navmap.correct.gif' => 'Correct',
  509:       'navmap.wrong.gif'   => 'Incorrect',
  510:       'navmap.open.gif'    => 'Open' );
  511: 
  512: # Defines a status->color mapping, null string means don't color
  513: my %colormap = 
  514:     ( $resObj->NETWORK_FAILURE        => '',
  515:       $resObj->CORRECT                => '',
  516:       $resObj->EXCUSED                => '#3333FF',
  517:       $resObj->PAST_DUE_ANSWER_LATER  => '',
  518:       $resObj->PAST_DUE_NO_ANSWER     => '',
  519:       $resObj->ANSWER_OPEN            => '#006600',
  520:       $resObj->OPEN_LATER             => '',
  521:       $resObj->TRIES_LEFT             => '',
  522:       $resObj->INCORRECT              => '',
  523:       $resObj->OPEN                   => '',
  524:       $resObj->NOTHING_SET            => '',
  525:       $resObj->ATTEMPTED              => '',
  526:       $resObj->ANSWER_SUBMITTED       => '',
  527:       $resObj->PARTIALLY_CORRECT      => '#006600'
  528:       );
  529: # And a special case in the nav map; what to do when the assignment
  530: # is not yet done and due in less than 24 hours
  531: my $hurryUpColor = "#FF0000";
  532: 
  533: sub close {
  534:     if ($env{'environment.remotenavmap'} ne 'on') { return ''; }
  535:     return(<<ENDCLOSE);
  536: <script type="text/javascript">
  537: window.status='Accessing Nav Control';
  538: menu=window.open("/adm/rat/empty.html","loncapanav",
  539:                  "height=600,width=400,scrollbars=1");
  540: window.status='Closing Nav Control';
  541: menu.close();
  542: window.status='Done.';
  543: </script>
  544: ENDCLOSE
  545: }
  546: 
  547: sub update {
  548:     if ($env{'environment.remotenavmap'} ne 'on') { return ''; }
  549:     if (!$env{'request.course.id'}) { return ''; }
  550:     if ($ENV{'REQUEST_URI'}=~m|^/adm/navmaps|) { return ''; }
  551:     return(<<ENDUPDATE);
  552: <form name="navform"></form>
  553: <script type="text/javascript">
  554: this.document.navform.action='/adm/navmaps#curloc';
  555: this.document.navform.target='loncapanav';
  556: this.document.navform.submit();
  557: </script>
  558: ENDUPDATE
  559: }
  560: 
  561: 
  562: sub addToFilter {
  563:     my $hashIn = shift;
  564:     my $addition = shift;
  565:     my %hash = %$hashIn;
  566:     $hash{$addition} = 1;
  567: 
  568:     return join (",", keys(%hash));
  569: }
  570: 
  571: sub removeFromFilter {
  572:     my $hashIn = shift;
  573:     my $subtraction = shift;
  574:     my %hash = %$hashIn;
  575: 
  576:     delete $hash{$subtraction};
  577:     return join(",", keys(%hash));
  578: }
  579: 
  580: sub getLinkForResource {
  581:     my $stack = shift;
  582:     my $res;
  583: 
  584:     # Check to see if there are any pages in the stack
  585:     foreach $res (@$stack) {
  586:         if (defined($res)) {
  587: 	    my $anchor;
  588: 	    if ($res->is_page()) {
  589: 		foreach my $item (@$stack) { if (defined($item)) { $anchor = $item; }  }
  590: 		$anchor=&escape($anchor->shown_symb());
  591: 		return ($res->link(),$res->shown_symb(),$anchor);
  592: 	    }
  593:             # in case folder was skipped over as "only sequence"
  594: 	    my ($map,$id,$src)=&Apache::lonnet::decode_symb($res->symb());
  595: 	    if ($map=~/\.page$/) {
  596: 		my $url=&Apache::lonnet::clutter($map);
  597: 		$anchor=&escape($src->shown_symb());
  598: 		return ($url,$res->shown_symb(),$anchor);
  599: 	    }
  600:         }
  601:     }
  602: 
  603:     # Failing that, return the src of the last resource that is defined
  604:     # (when we first recurse on a map, it puts an undefined resource
  605:     # on the bottom because $self->{HERE} isn't defined yet, and we
  606:     # want the src for the map anyhow)
  607:     foreach my $item (@$stack) {
  608:         if (defined($item)) { $res = $item; }
  609:     }
  610: 
  611:     if ($res) {
  612: 	return ($res->link(),$res->shown_symb());
  613:     }
  614:     return;
  615: }
  616: 
  617: 
  618: 
  619: sub getDescription {
  620:     my $res = shift;
  621:     my $part = shift;
  622:     my $status = $res->status($part);
  623: 
  624:     my $open = $res->opendate($part);
  625:     my $due = $res->duedate($part);
  626:     my $answer = $res->answerdate($part);
  627: 
  628:     if ($status == $res->NETWORK_FAILURE) { 
  629:         return &mt("Having technical difficulties; please check status later"); 
  630:     }
  631:     if ($status == $res->NOTHING_SET) {
  632:         return &mt("Not currently assigned.");
  633:     }
  634:     if ($status == $res->OPEN_LATER) {
  635:         return &mt("Open ") .timeToHumanString($open,'start');
  636:     }
  637:     if ($status == $res->OPEN) {
  638:         if ($due) {
  639: 	    if ($res->is_practice()) {
  640: 		return &mt("Closes ")."  " .timeToHumanString($due,'start');
  641: 	    } else {
  642: 		return &mt("Due")."  " .timeToHumanString($due,'end');
  643: 	    }
  644:         } else {
  645:             return &mt("Open, no due date");
  646:         }
  647:     }
  648:     if ($status == $res->PAST_DUE_ANSWER_LATER) {
  649:         return &mt("Answer open")." " .timeToHumanString($answer,'start');
  650:     }
  651:     if ($status == $res->PAST_DUE_NO_ANSWER) {
  652: 	if ($res->is_practice()) {
  653: 	    return &mt("Closed")." " . timeToHumanString($due,'start');
  654: 	} else {
  655: 	    return &mt("Was due")." " . timeToHumanString($due,'end');
  656: 	}
  657:     }
  658:     if (($status == $res->ANSWER_OPEN || $status == $res->PARTIALLY_CORRECT)
  659: 	&& $res->handgrade($part) ne 'yes') {
  660:         return &mt("Answer available");
  661:     }
  662:     if ($status == $res->EXCUSED) {
  663:         return &mt("Excused by instructor");
  664:     }
  665:     if ($status == $res->ATTEMPTED) {
  666:         return &mt("Answer submitted, not yet graded");
  667:     }
  668:     if ($status == $res->TRIES_LEFT) {
  669:         my $tries = $res->tries($part);
  670:         my $maxtries = $res->maxtries($part);
  671:         my $triesString = "";
  672:         if ($tries && $maxtries) {
  673:             $triesString = '<font size="-1"><i>('.&mt('[_1] of [quant,_2,try,tries] used',$tries,$maxtries).')</i></font>';
  674:             if ($maxtries > 1 && $maxtries - $tries == 1) {
  675:                 $triesString = "<b>$triesString</b>";
  676:             }
  677:         }
  678:         if ($due) {
  679:             return &mt("Due")." " . timeToHumanString($due,'end') .
  680:                 " $triesString";
  681:         } else {
  682:             return &mt("No due date")." $triesString";
  683:         }
  684:     }
  685:     if ($status == $res->ANSWER_SUBMITTED) {
  686:         return &mt('Answer submitted');
  687:     }
  688: }
  689: 
  690: 
  691: sub dueInLessThan24Hours {
  692:     my $res = shift;
  693:     my $part = shift;
  694:     my $status = $res->status($part);
  695: 
  696:     return ($status == $res->OPEN() ||
  697:             $status == $res->TRIES_LEFT()) &&
  698: 	    $res->duedate($part) && $res->duedate($part) < time()+(24*60*60) &&
  699: 	    $res->duedate($part) > time();
  700: }
  701: 
  702: 
  703: sub lastTry {
  704:     my $res = shift;
  705:     my $part = shift;
  706: 
  707:     my $tries = $res->tries($part);
  708:     my $maxtries = $res->maxtries($part);
  709:     return $tries && $maxtries && $maxtries > 1 &&
  710:         $maxtries - $tries == 1 && $res->duedate($part) &&
  711:         $res->duedate($part) > time();
  712: }
  713: 
  714: 
  715: sub advancedUser {
  716:     return $env{'request.role.adv'};
  717: }
  718: 
  719: sub timeToHumanString {
  720:     my ($time,$type,$format) = @_;
  721: 
  722:     # zero, '0' and blank are bad times
  723:     if (!$time) {
  724:         return &mt('never');
  725:     }
  726:     unless (&Apache::lonlocal::current_language()=~/^en/) {
  727: 	return &Apache::lonlocal::locallocaltime($time);
  728:     } 
  729:     my $now = time();
  730: 
  731:     # Positive = future
  732:     my $delta = $time - $now;
  733: 
  734:     my $minute = 60;
  735:     my $hour = 60 * $minute;
  736:     my $day = 24 * $hour;
  737:     my $week = 7 * $day;
  738:     my $inPast = 0;
  739: 
  740:     # Logic in comments:
  741:     # Is it now? (extremely unlikely)
  742:     if ( $delta == 0 ) {
  743:         return "this instant";
  744:     }
  745: 
  746:     if ($delta < 0) {
  747:         $inPast = 1;
  748:         $delta = -$delta;
  749:     }
  750: 
  751:     if ( $delta > 0 ) {
  752: 
  753:         my $tense = $inPast ? " ago" : "";
  754:         my $prefix = $inPast ? "" : "in ";
  755:         
  756:         # Less than a minute
  757:         if ( $delta < $minute ) {
  758:             if ($delta == 1) { return "${prefix}1 second$tense"; }
  759:             return "$prefix$delta seconds$tense";
  760:         }
  761: 
  762:         # Less than an hour
  763:         if ( $delta < $hour ) {
  764:             # If so, use minutes
  765:             my $minutes = floor($delta / 60);
  766:             if ($minutes == 1) { return "${prefix}1 minute$tense"; }
  767:             return "$prefix$minutes minutes$tense";
  768:         }
  769:         
  770:         # Is it less than 24 hours away? If so,
  771:         # display hours + minutes
  772:         if ( $delta < $hour * 24) {
  773:             my $hours = floor($delta / $hour);
  774:             my $minutes = floor(($delta % $hour) / $minute);
  775:             my $hourString = "$hours hours";
  776:             my $minuteString = ", $minutes minutes";
  777:             if ($hours == 1) {
  778:                 $hourString = "1 hour";
  779:             }
  780:             if ($minutes == 1) {
  781:                 $minuteString = ", 1 minute";
  782:             }
  783:             if ($minutes == 0) {
  784:                 $minuteString = "";
  785:             }
  786:             return "$prefix$hourString$minuteString$tense";
  787:         }
  788: 
  789: 	my $dt = DateTime->from_epoch(epoch => $time)
  790: 	                 ->set_time_zone(&Apache::lonlocal::gettimezone());
  791: 
  792: 	# If there's a caller supplied format, use it.
  793: 
  794: 	if ($format ne '') {
  795: 	    my $timeStr = $dt->strftime($format);
  796: 	    return $timeStr.' ('.$dt->time_zone_short_name().')';
  797: 	}
  798: 
  799:         # Less than 5 days away, display day of the week and
  800:         # HH:MM
  801: 
  802:         if ( $delta < $day * 5 ) {
  803:             my $timeStr = $dt->strftime("%A, %b %e at %I:%M %P (%Z)");
  804:             $timeStr =~ s/12:00 am/00:00/;
  805:             $timeStr =~ s/12:00 pm/noon/;
  806:             return ($inPast ? "last " : "this ") .
  807:                 $timeStr;
  808:         }
  809:         
  810: 	my $conjunction='on';
  811: 	if ($type eq 'start') {
  812: 	    $conjunction='at';
  813: 	} elsif ($type eq 'end') {
  814: 	    $conjunction='by';
  815: 	}
  816:         # Is it this year?
  817: 	my $dt_now = DateTime->from_epoch(epoch => $now)
  818: 	                     ->set_time_zone(&Apache::lonlocal::gettimezone());
  819:         if ( $dt->year() == $dt_now->year()) {
  820:             # Return on Month Day, HH:MM meridian
  821:             my $timeStr = $dt->strftime("$conjunction %A, %b %e at %I:%M %P (%Z)");
  822:             $timeStr =~ s/12:00 am/00:00/;
  823:             $timeStr =~ s/12:00 pm/noon/;
  824:             return $timeStr;
  825:         }
  826: 
  827:         # Not this year, so show the year
  828:         my $timeStr = 
  829: 	    $dt->strftime("$conjunction %A, %b %e %Y at %I:%M %P (%Z)");
  830:         $timeStr =~ s/12:00 am/00:00/;
  831:         $timeStr =~ s/12:00 pm/noon/;
  832:         return $timeStr;
  833:     }
  834: }
  835: 
  836: 
  837: sub resource { return 0; }
  838: sub communication_status { return 1; }
  839: sub quick_status { return 2; }
  840: sub long_status { return 3; }
  841: sub part_status_summary { return 4; }
  842: 
  843: sub render_resource {
  844:     my ($resource, $part, $params) = @_;
  845: 
  846:     my $nonLinkedText = ''; # stuff after resource title not in link
  847: 
  848:     my $link = $params->{"resourceLink"};
  849: 
  850:     #  The URL part is not escaped at this point, but the symb is... 
  851:     #  The stuff to the left of the ? must have ' replaced by \' since
  852:     #  it will be quoted with ' in the href.
  853: 
  854:     my ($left,$right) = split(/\?/, $link);
  855:     $link = $left.'?'.$right;
  856: 
  857:     my $src = $resource->src();
  858:     my $it = $params->{"iterator"};
  859:     my $filter = $it->{FILTER};
  860: 
  861:     my $title = $resource->compTitle();
  862: 
  863:     my $partLabel = "";
  864:     my $newBranchText = "";
  865:     my $location=&Apache::loncommon::lonhttpdurl("/adm/lonIcons");
  866:     # If this is a new branch, label it so
  867:     if ($params->{'isNewBranch'}) {
  868:         $newBranchText = "<img src='$location/branch.gif' alt=".mt('Branch')." />";
  869:     }
  870: 
  871:     # links to open and close the folder
  872: 
  873:     my $whitespace = $location.'/whitespace_21.gif';
  874:     my $linkopen = "<img src='$whitespace' alt='' />"."<a href=\"$link\">";
  875:     my $linkclose = "</a>";
  876: 
  877:     # Default icon: unknown page
  878:     my $icon = "<img class=\"LC_contentImage\" src='$location/unknown.gif' alt='' />";
  879:     
  880:     if ($resource->is_problem()) {
  881:         if ($part eq '0' || $params->{'condensed'}) {
  882: 	    $icon = '<img class="LC_contentImage" src="'.$location.'/';
  883: 	    if ($resource->is_task()) {
  884: 		$icon .= 'task.gif" alt="'.&mt('Task');
  885: 	    } else {
  886: 		$icon .= 'problem.gif" alt="'.&mt('Problem');
  887: 	    }
  888: 	    $icon .='" />';
  889:         } else {
  890:             $icon = $params->{'indentString'};
  891:         }
  892:     } else {
  893: 	$icon = "<img class=\"LC_contentImage\" src='".&Apache::loncommon::icon($resource->src)."' alt='' />";
  894:     }
  895: 
  896:     # Display the correct map icon to open or shut map
  897:     if ($resource->is_map()) {
  898:         my $mapId = $resource->map_pc();
  899:         my $nowOpen = !defined($filter->{$mapId});
  900:         if ($it->{CONDITION}) {
  901:             $nowOpen = !$nowOpen;
  902:         }
  903: 	
  904: 	my $folderType = $resource->is_sequence() ? 'folder' : 'page';
  905:         my $title=$resource->title;
  906: 		$title=~s/\"/\&qout;/g;
  907:         if (!$params->{'resource_no_folder_link'}) {
  908:             $icon = "navmap.$folderType." . ($nowOpen ? 'closed' : 'open') . '.gif';
  909:             $icon = "<img src='$location/arrow." . ($nowOpen ? 'closed' : 'open') . ".gif' alt='' />"
  910:                     ."<img class=\"LC_contentImage\" src='$location/$icon' alt=\""
  911:                     .($nowOpen ? &mt('Open Folder') : &mt('Close Folder')).' '.$title."\" />";			
  912:             $linkopen = "<a href=\"" . $params->{'url'} . '?' . 
  913:                 $params->{'queryString'} . '&amp;filter=';
  914:             $linkopen .= ($nowOpen xor $it->{CONDITION}) ?
  915:                 addToFilter($filter, $mapId) :
  916:                 removeFromFilter($filter, $mapId);
  917:             $linkopen .= "&amp;condition=" . $it->{CONDITION} . '&amp;hereType='
  918:                 . $params->{'hereType'} . '&amp;here=' .
  919:                 &escape($params->{'here'}) . 
  920:                 '&amp;jump=' .
  921:                 &escape($resource->symb()) . 
  922:                 "&amp;folderManip=1\">";
  923: 
  924:         } else {
  925:             # Don't allow users to manipulate folder
  926:             $icon = "navmap.$folderType." . ($nowOpen ? 'closed' : 'open') . '.gif';
  927:             $icon = "<img class=\"LC_space\" src='$whitespace' alt='' />"."<img class=\"LC_contentImage\" src='$location/$icon' alt=\"".($nowOpen ? &mt('Open Folder') : &mt('Close Folder')).' '.$title."\" />";
  928: 
  929:             $linkopen = "";
  930:             $linkclose = "";
  931:         }
  932:     }
  933: 
  934:     if ($resource->randomout()) {
  935:         $nonLinkedText .= ' <i>('.&mt('hidden').')</i> ';
  936:     }
  937:     if (!$resource->condval()) {
  938:         $nonLinkedText .= ' <i>('.&mt('conditionally hidden').')</i> ';
  939:     }
  940:     if (($resource->is_practice()) && ($resource->is_raw_problem())) {
  941:         $nonLinkedText .=' <font color="green"><b>'.&mt('not graded').'</b></font>';
  942:     }
  943: 
  944:     # We're done preparing and finally ready to start the rendering
  945:     my $result = '<td class="LC_middle">';
  946:     my $newfolderType = $resource->is_sequence() ? 'folder' : 'page';
  947: 	
  948:     my $indentLevel = $params->{'indentLevel'};
  949:     if ($newBranchText) { $indentLevel--; }
  950: 
  951:     # print indentation
  952:     for (my $i = 0; $i < $indentLevel; $i++) {
  953:         $result .= $params->{'indentString'};
  954:     }
  955: 
  956:     # Decide what to display
  957:     $result .= "$newBranchText$linkopen$icon$linkclose";
  958:     
  959:     my $curMarkerBegin = '';
  960:     my $curMarkerEnd = '';
  961: 
  962:     # Is this the current resource?
  963:     if (!$params->{'displayedHereMarker'} && 
  964:         $resource->symb() eq $params->{'here'} ) {
  965:         $curMarkerBegin = '<em>';
  966:         $curMarkerEnd = '</em>';
  967: 	$params->{'displayedHereMarker'} = 1;
  968:     }
  969: 
  970:     if ($resource->is_problem() && $part ne '0' && 
  971:         !$params->{'condensed'}) {
  972: 	my $displaypart=$resource->part_display($part);
  973:         $partLabel = " (".&mt('Part: [_1]', $displaypart).")";
  974: 	if ($link!~/\#/) { $link.='#'.&escape($part); }
  975:         $title = "";
  976:     }
  977: 
  978:     if ($params->{'condensed'} && $resource->countParts() > 1) {
  979:         $nonLinkedText .= ' ('.&mt('[_1] parts', $resource->countParts()).')';
  980:     }
  981: 
  982:     my $target;
  983:     if ($env{'environment.remotenavmap'} eq 'on') {
  984: 	$target=' target="loncapaclient" ';
  985:     }
  986:     if (!$params->{'resource_nolink'} && !$resource->is_sequence() && !$resource->is_empty_sequence) {
  987:         $result .= "$curMarkerBegin<a $target href=\"$link\">$title$partLabel</a>$curMarkerEnd$nonLinkedText</td>";
  988:     } else {
  989:         $result .= "$curMarkerBegin$linkopen$title$partLabel</a>$curMarkerEnd$nonLinkedText</td>";
  990:     }
  991: 
  992:     return $result;
  993: }
  994: 
  995: sub render_communication_status {
  996:     my ($resource, $part, $params) = @_;
  997:     my $discussionHTML = ""; my $feedbackHTML = ""; my $errorHTML = "";
  998: 
  999:     my $link = $params->{"resourceLink"};
 1000:     my $target;
 1001:     if ($env{'environment.remotenavmap'} eq 'on') {
 1002: 	$target=' target="loncapaclient" ';
 1003:     }
 1004:     my $linkopen = "<a $target href=\"$link\">";
 1005:     my $linkclose = "</a>";
 1006:     my $location=&Apache::loncommon::lonhttpdurl("/adm/lonMisc");
 1007:     if ($resource->hasDiscussion()) {
 1008:         $discussionHTML = $linkopen .
 1009:             '<img alt="'.&mt('New Discussion').'" src="'.$location.'/chat.gif" />' .
 1010:             $linkclose;
 1011:     }
 1012:     
 1013:     if ($resource->getFeedback()) {
 1014:         my $feedback = $resource->getFeedback();
 1015:         foreach my $msgid (split(/\,/, $feedback)) {
 1016:             if ($msgid) {
 1017:                 $feedbackHTML .= '&nbsp;<a '.$target.' href="/adm/email?display='
 1018:                     . &escape($msgid) . '">'
 1019:                     . '<img alt="'.&mt('New E-mail').'" src="'.$location.'/feedback.gif" /></a>';
 1020:             }
 1021:         }
 1022:     }
 1023:     
 1024:     if ($resource->getErrors()) {
 1025:         my $errors = $resource->getErrors();
 1026:         my $errorcount = 0;
 1027:         foreach my $msgid (split(/,/, $errors)) {
 1028:             last if ($errorcount>=10); # Only output 10 bombs maximum
 1029:             if ($msgid) {
 1030:                 $errorcount++;
 1031:                 $errorHTML .= '&nbsp;<a '.$target.' href="/adm/email?display='
 1032:                     . &escape($msgid) . '">'
 1033:                     . '<img alt="'.&mt('New Error').'" src="'.$location.'/bomb.gif" /></a>';
 1034:             }
 1035:         }
 1036:     }
 1037: 
 1038:     if ($params->{'multipart'} && $part != '0') {
 1039: 	$discussionHTML = $feedbackHTML = $errorHTML = '';
 1040:     }
 1041:     return "<td class=\"LC_middle\">$discussionHTML$feedbackHTML$errorHTML&nbsp;</td>";
 1042: 
 1043: }
 1044: sub render_quick_status {
 1045:     my ($resource, $part, $params) = @_;
 1046:     my $result = "";
 1047:     my $firstDisplayed = !$params->{'condensed'} && 
 1048:         $params->{'multipart'} && $part eq "0";
 1049: 
 1050:     my $link = $params->{"resourceLink"};
 1051:     my $target;
 1052:     if ($env{'environment.remotenavmap'} eq 'on') {
 1053: 	$target=' target="loncapaclient" ';
 1054:     }
 1055:     my $linkopen = "<a $target href=\"$link\">";
 1056:     my $linkclose = "</a>";
 1057: 	
 1058: 	$result .= '<td class="LC_middle">';
 1059:     if ($resource->is_problem() &&
 1060:         !$firstDisplayed) {
 1061:         my $icon = $statusIconMap{$resource->simpleStatus($part)};
 1062:         my $alt = $iconAltTags{$icon};
 1063:         if ($icon) {
 1064: 	    my $location=
 1065: 		&Apache::loncommon::lonhttpdurl("/adm/lonIcons/$icon");
 1066:             $result .= "$linkopen<img src='$location' alt='$alt' />$linkclose";
 1067:         } else {
 1068:             $result .= "&nbsp;";
 1069:         }
 1070:     } else { # not problem, no icon
 1071:         $result .= "&nbsp;";
 1072:     }
 1073: 	$result .= "</td>\n";
 1074:     return $result;
 1075: }
 1076: sub render_long_status {
 1077:     my ($resource, $part, $params) = @_;
 1078:     my $result = '<td class="LC_middle LC_right">';
 1079:     my $firstDisplayed = !$params->{'condensed'} && 
 1080:         $params->{'multipart'} && $part eq "0";
 1081:                 
 1082:     my $color;
 1083:     if ($resource->is_problem() || $resource->is_practice()) {
 1084:         $color = $colormap{$resource->status};
 1085:         
 1086:         if (dueInLessThan24Hours($resource, $part) ||
 1087:             lastTry($resource, $part)) {
 1088:             $color = $hurryUpColor;
 1089:         }
 1090:     }
 1091:     
 1092:     if ($resource->kind() eq "res" &&
 1093:         ($resource->is_problem() || $resource->is_practice()) &&
 1094:         !$firstDisplayed) {
 1095:         if ($color) {$result .= "<font color=\"$color\"><b>"; }
 1096:         $result .= getDescription($resource, $part);
 1097:         if ($color) {$result .= "</b></font>"; }
 1098:     }
 1099:     if ($resource->is_map() && &advancedUser() && $resource->randompick()) {
 1100:         $result .= &mt('(randomly select [_1])', $resource->randompick());
 1101:     }
 1102:     if ($resource->is_map() && &advancedUser() && $resource->randomorder()) {
 1103:         $result .= &mt('(randomly ordered)');
 1104:     }
 1105: 
 1106:     # Debugging code
 1107:     #$result .= " " . $resource->awarded($part) . '/' . $resource->weight($part) .
 1108:     #	' - Part: ' . $part;
 1109: 
 1110:     $result .= "</td>\n";
 1111:     
 1112:     return $result;
 1113: }
 1114: 
 1115: # Colors obtained by taking the icons, matching the colors, and
 1116: # possibly reducing the Value (HSV) of the color, if it's too bright
 1117: # for text, generally by one third or so.
 1118: my %statusColors = 
 1119:     (
 1120:      $resObj->CLOSED => '#000000',
 1121:      $resObj->OPEN   => '#998b13',
 1122:      $resObj->CORRECT => '#26933f',
 1123:      $resObj->INCORRECT => '#c48207',
 1124:      $resObj->ATTEMPTED => '#a87510',
 1125:      $resObj->ERROR => '#000000'
 1126:      );
 1127: my %statusStrings = 
 1128:     (
 1129:      $resObj->CLOSED => 'Not yet open',
 1130:      $resObj->OPEN   => 'Open',
 1131:      $resObj->CORRECT => 'Correct',
 1132:      $resObj->INCORRECT => 'Incorrect',
 1133:      $resObj->ATTEMPTED => 'Attempted',
 1134:      $resObj->ERROR => 'Network Error'
 1135:      );
 1136: my @statuses = ($resObj->CORRECT, $resObj->ATTEMPTED, $resObj->INCORRECT, $resObj->OPEN, $resObj->CLOSED, $resObj->ERROR);
 1137: 
 1138: sub render_parts_summary_status {
 1139:     my ($resource, $part, $params) = @_;
 1140:     if (!$resource->is_problem() && !$resource->contains_problem) { return '<td></td>'; }
 1141:     if ($params->{showParts}) { 
 1142: 	return '<td></td>';
 1143:     }
 1144: 
 1145:     my $td = "<td align='right'>\n";
 1146:     my $endtd = "</td>\n";
 1147:     my @probs;
 1148: 
 1149:     if ($resource->contains_problem) {
 1150: 	@probs=$resource->retrieveResources($resource,sub { $_[0]->is_problem() },1,0);
 1151:     } else {
 1152: 	@probs=($resource);
 1153:     }
 1154:     my $return;
 1155:     my %overallstatus;
 1156:     my $totalParts;
 1157:     foreach my $resource (@probs) {
 1158: 	# If there is a single part, just show the simple status
 1159: 	if ($resource->singlepart()) {
 1160: 	    my $status = $resource->simpleStatus(${$resource->parts}[0]);
 1161: 	    $overallstatus{$status}++;
 1162: 	    $totalParts++;
 1163: 	    next;
 1164: 	}
 1165: 	# Now we can be sure the $part doesn't really matter.
 1166: 	my $statusCount = $resource->simpleStatusCount();
 1167: 	my @counts;
 1168: 	foreach my $status (@statuses) {
 1169: 	    # decouple display order from the simpleStatusCount order
 1170: 	    my $slot = Apache::lonnavmaps::resource::statusToSlot($status);
 1171: 	    if ($statusCount->[$slot]) {
 1172: 		$overallstatus{$status}+=$statusCount->[$slot];
 1173: 		$totalParts+=$statusCount->[$slot];
 1174: 	    }
 1175: 	}
 1176:     }
 1177:     $return.= $td . $totalParts . ' parts: ';
 1178:     foreach my $status (@statuses) {
 1179: 	if ($overallstatus{$status}) {
 1180: 	    $return.="<font color='" . $statusColors{$status} .
 1181: 		"'>" . $overallstatus{$status} . ' '
 1182: 		. $statusStrings{$status} . "</font>";
 1183: 	}
 1184:     }
 1185:     $return.= $endtd;
 1186:     return $return;
 1187: }
 1188: 
 1189: my @preparedColumns = (\&render_resource, \&render_communication_status,
 1190:                        \&render_quick_status, \&render_long_status,
 1191: 		       \&render_parts_summary_status);
 1192: 
 1193: sub setDefault {
 1194:     my ($val, $default) = @_;
 1195:     if (!defined($val)) { return $default; }
 1196:     return $val;
 1197: }
 1198: 
 1199: sub cmp_title {
 1200:     my ($atitle,$btitle) = (lc($_[0]->compTitle),lc($_[1]->compTitle));
 1201:     $atitle=~s/^\s*//;
 1202:     $btitle=~s/^\s*//;
 1203:     return $atitle cmp $btitle;
 1204: }
 1205: 
 1206: sub render {
 1207:     my $args = shift;
 1208:     &Apache::loncommon::get_unprocessed_cgi($ENV{QUERY_STRING});
 1209:     my $result = '';
 1210:     # Configure the renderer.
 1211:     my $cols = $args->{'cols'};
 1212:     if (!defined($cols)) {
 1213:         # no columns, no nav maps.
 1214:         return '';
 1215:     }
 1216:     my $navmap;
 1217:     if (defined($args->{'navmap'})) {
 1218:         $navmap = $args->{'navmap'};
 1219:     }
 1220: 
 1221:     my $r = $args->{'r'};
 1222:     my $queryString = $args->{'queryString'};
 1223:     my $jump = $args->{'jump'};
 1224:     my $here = $args->{'here'};
 1225:     my $suppressNavmap = setDefault($args->{'suppressNavmap'}, 0);
 1226:     my $closeAllPages = setDefault($args->{'closeAllPages'}, 0);
 1227:     my $currentJumpDelta = 2; # change this to change how many resources are displayed
 1228:                              # before the current resource when using #current
 1229: 
 1230:     # If we were passed 'here' information, we are not rendering
 1231:     # after a folder manipulation, and we were not passed an
 1232:     # iterator, make sure we open the folders to show the "here"
 1233:     # marker
 1234:     my $filterHash = {};
 1235:     # Figure out what we're not displaying
 1236:     foreach my $item (split(/\,/, $env{"form.filter"})) {
 1237:         if ($item) {
 1238:             $filterHash->{$item} = "1";
 1239:         }
 1240:     }
 1241: 
 1242:     # Filter: Remember filter function and add our own filter: Refuse
 1243:     # to show hidden resources unless the user can see them.
 1244:     my $userCanSeeHidden = advancedUser();
 1245:     my $filterFunc = setDefault($args->{'filterFunc'},
 1246:                                 sub {return 1;});
 1247:     if (!$userCanSeeHidden) {
 1248:         # Without renaming the filterfunc, the server seems to go into
 1249:         # an infinite loop
 1250:         my $oldFilterFunc = $filterFunc;
 1251:         $filterFunc = sub { my $res = shift; return !$res->randomout() && 
 1252:                                 &$oldFilterFunc($res);};
 1253:     }
 1254: 
 1255:     my $condition = 0;
 1256:     if ($env{'form.condition'}) {
 1257:         $condition = 1;
 1258:     }
 1259: 
 1260:     if (!$env{'form.folderManip'} && !defined($args->{'iterator'})) {
 1261:         # Step 1: Check to see if we have a navmap
 1262:         if (!defined($navmap)) {
 1263:             $navmap = Apache::lonnavmaps::navmap->new();
 1264: 	    if (!defined($navmap)) {
 1265: 		# no longer in course
 1266: 		return '<span class="LC_error">'.&mt('No course selected').'</span><br />
 1267:                         <a href="/adm/roles">'.&mt('Select a course').'</a><br />';
 1268: 	    }
 1269: 	}
 1270: 
 1271:         # Step two: Locate what kind of here marker is necessary
 1272:         # Determine where the "here" marker is and where the screen jumps to.
 1273: 
 1274:         if ($env{'form.postsymb'} ne '') {
 1275:             $here = $jump = &Apache::lonnet::symbclean($env{'form.postsymb'});
 1276:         } elsif ($env{'form.postdata'} ne '') {
 1277:             # couldn't find a symb, is there a URL?
 1278:             my $currenturl = $env{'form.postdata'};
 1279:             #$currenturl=~s/^http\:\/\///;
 1280:             #$currenturl=~s/^[^\/]+//;
 1281:             
 1282:             $here = $jump = &Apache::lonnet::symbread($currenturl);
 1283: 	}
 1284: 	if ($here eq '') {
 1285: 	    my $last;
 1286: 	    if (tie(my %hash,'GDBM_File',$env{'request.course.fn'}.'_symb.db',
 1287:                     &GDBM_READER(),0640)) {
 1288: 		$last=$hash{'last_known'};
 1289: 		untie(%hash);
 1290: 	    }
 1291: 	    if ($last) { $here = $jump = $last; }
 1292: 	}
 1293: 
 1294:         # Step three: Ensure the folders are open
 1295:         my $mapIterator = $navmap->getIterator(undef, undef, undef, 1);
 1296:         my $curRes;
 1297:         my $found = 0;
 1298:         
 1299:         # We only need to do this if we need to open the maps to show the
 1300:         # current position. This will change the counter so we can't count
 1301:         # for the jump marker with this loop.
 1302:         while ($here && ($curRes = $mapIterator->next()) && !$found) {
 1303:             if (ref($curRes) && $curRes->symb() eq $here) {
 1304:                 my $mapStack = $mapIterator->getStack();
 1305:                 
 1306:                 # Ensure the parent maps are open
 1307:                 for my $map (@{$mapStack}) {
 1308:                     if ($condition) {
 1309:                         undef $filterHash->{$map->map_pc()};
 1310:                     } else {
 1311:                         $filterHash->{$map->map_pc()} = 1;
 1312:                     }
 1313:                 }
 1314:                 $found = 1;
 1315:             }
 1316:         }            
 1317:     }        
 1318: 
 1319:     if ( !defined($args->{'iterator'}) && $env{'form.folderManip'} ) { # we came from a user's manipulation of the nav page
 1320:         # If this is a click on a folder or something, we want to preserve the "here"
 1321:         # from the querystring, and get the new "jump" marker
 1322:         $here = $env{'form.here'};
 1323:         $jump = $env{'form.jump'};
 1324:     } 
 1325:     
 1326:     my $it = $args->{'iterator'};
 1327:     if (!defined($it)) {
 1328:         # Construct a default iterator based on $env{'form.'} information
 1329:         
 1330:         # Step 1: Check to see if we have a navmap
 1331:         if (!defined($navmap)) {
 1332:             $navmap = Apache::lonnavmaps::navmap->new();
 1333:             if (!defined($navmap)) {
 1334:                 # no longer in course
 1335:                 return '<span class="LC_error">'.&mt('No course selected').'</span><br />
 1336:                         <a href="/adm/roles">'.&mt('Select a course').'</a><br />';
 1337:             }
 1338:         }
 1339: 
 1340:         # See if we're being passed a specific map
 1341:         if ($args->{'iterator_map'}) {
 1342:             my $map = $args->{'iterator_map'};
 1343:             $map = $navmap->getResourceByUrl($map);
 1344:             my $firstResource = $map->map_start();
 1345:             my $finishResource = $map->map_finish();
 1346: 
 1347:             $args->{'iterator'} = $it = $navmap->getIterator($firstResource, $finishResource, $filterHash, $condition);
 1348:         } else {
 1349:             $args->{'iterator'} = $it = $navmap->getIterator(undef, undef, $filterHash, $condition,undef,$args->{'include_top_level_map'});
 1350:         }
 1351:     }
 1352: 
 1353:     # (re-)Locate the jump point, if any
 1354:     # Note this does not take filtering or hidden into account... need
 1355:     # to be fixed?
 1356:     my $mapIterator = $navmap->getIterator(undef, undef, $filterHash, 0);
 1357:     my $curRes;
 1358:     my $foundJump = 0;
 1359:     my $counter = 0;
 1360:     
 1361:     while (($curRes = $mapIterator->next()) && !$foundJump) {
 1362:         if (ref($curRes)) { $counter++; }
 1363:         
 1364:         if (ref($curRes) && $jump eq $curRes->symb()) {
 1365:             
 1366:             # This is why we have to use the main iterator instead of the
 1367:             # potentially faster DFS: The count has to be the same, so
 1368:             # the order has to be the same, which DFS won't give us.
 1369:             $args->{'currentJumpIndex'} = $counter;
 1370:             $foundJump = 1;
 1371:         }
 1372:     }
 1373: 
 1374:     my $showParts = setDefault($args->{'showParts'}, 1);
 1375:     my $condenseParts = setDefault($args->{'condenseParts'}, 1);
 1376:     # keeps track of when the current resource is found,
 1377:     # so we can back up a few and put the anchor above the
 1378:     # current resource
 1379:     my $printKey = $args->{'printKey'};
 1380:     my $printCloseAll = $args->{'printCloseAll'};
 1381:     if (!defined($printCloseAll)) { $printCloseAll = 1; }
 1382:    
 1383:     # Print key?
 1384:     if ($printKey) {
 1385:         $result .= '<table border="0" cellpadding="2" cellspacing="0">';
 1386:         $result.='<tr><td align="right" valign="bottom">Key:&nbsp;&nbsp;</td>';
 1387: 	my $location=&Apache::loncommon::lonhttpdurl("/adm/lonMisc");
 1388:         if ($navmap->{LAST_CHECK}) {
 1389:             $result .= 
 1390:                 '<img src="'.$location.'/chat.gif"> '.&mt('New discussion since').' '.
 1391:                 strftime("%A, %b %e at %I:%M %P", localtime($navmap->{LAST_CHECK})).
 1392:                 '</td><td align="center" valign="bottom">&nbsp;&nbsp;'.
 1393:                 '<img src="'.$location.'/feedback.gif"> '.&mt('New message (click to open)').'<p>'.
 1394:                 '</td>'; 
 1395:         } else {
 1396:             $result .= '<td align="center" valign="bottom">&nbsp;&nbsp;'.
 1397:                 '<img src="'.$location.'/chat.gif"> '.&mt('Discussions').'</td><td align="center" valign="bottom">'.
 1398:                 '&nbsp;&nbsp;<img src="'.$location.'/feedback.gif"> '.&mt('New message (click to open)').
 1399:                 '</td>'; 
 1400:         }
 1401: 
 1402:         $result .= '</tr></table>';
 1403:     }
 1404: 
 1405:     if ($printCloseAll && !$args->{'resource_no_folder_link'}) {
 1406: 	my ($link,$text);
 1407:         if ($condition) {
 1408: 	    $link='"navmaps?condition=0&amp;filter=&amp;'.$queryString.
 1409: 		'&here='.&escape($here).'"';
 1410: 	    $text='Close all folders';
 1411:         } else {
 1412: 	    $link='"navmaps?condition=1&amp;filter=&amp;'.$queryString.
 1413: 		'&here='.&escape($here).'"';
 1414: 	    $text='Open all folders';
 1415:         }
 1416: 	if ($args->{'caller'} eq 'navmapsdisplay') {
 1417: 	    &add_linkitem($args->{'linkitems'},'changefolder',
 1418: 			  'location.href='.$link,$text);
 1419: 	} else {
 1420: 	    $result.='<a href='.$link.'>'.&mt($text).'</a>';
 1421: 	}
 1422:         $result .= "\n";
 1423:     }
 1424: 
 1425:     # Check for any unread discussions in all resources.
 1426:     if ($args->{'caller'} eq 'navmapsdisplay') {
 1427: 	&add_linkitem($args->{'linkitems'},'clearbubbles',
 1428: 		      'document.clearbubbles.submit()',
 1429: 		      'Mark all posts read');
 1430: 	my $time=time;
 1431: 	$result .= (<<END);
 1432:     <form name="clearbubbles" method="post" action="/adm/feedback">
 1433: 	<input type="hidden" name="navurl" value="$ENV{'QUERY_STRING'}" />
 1434: 	<input type="hidden" name="navtime" value="$time" />
 1435: END
 1436:         if ($args->{'sort'} eq 'discussion') { 
 1437: 	    my $totdisc = 0;
 1438: 	    my $haveDisc = '';
 1439: 	    my @allres=$navmap->retrieveResources();
 1440: 	    foreach my $resource (@allres) {
 1441: 		if ($resource->hasDiscussion()) {
 1442: 		    $haveDisc .= $resource->wrap_symb().':';
 1443: 		    $totdisc ++;
 1444: 		}
 1445: 	    }
 1446: 	    if ($totdisc > 0) {
 1447: 		$haveDisc =~ s/:$//;
 1448: 		$result .= (<<END);
 1449: 	<input type="hidden" name="navmaps" value="$haveDisc" />
 1450:     </form>
 1451: END
 1452:             }
 1453: 	}
 1454: 	$result.='</form>';
 1455:     }
 1456: 
 1457:    
 1458:     if ($args->{'caller'} eq 'navmapsdisplay') {
 1459:         $result .= '<table><tr><td>'.
 1460:                    &Apache::loncommon::help_open_menu('Navigation Screen','Navigation_Screen',undef,'RAT').'</td>';
 1461: 	if ($env{'environment.remotenavmap'} ne 'on') {
 1462: 	    $result .= '<td>&nbsp;</td>'; 
 1463:         } else {
 1464: 	    $result .= '</tr><tr>'; 
 1465:         }
 1466: 	$result.="<td class=\"LC_middle\">".mt('Tools:')."</td>";
 1467: 	$result.=&show_linkitems_toolbar($args->{'linkitems'});
 1468:         if ($args->{'sort_html'}) {
 1469: 	    if ($env{'environment.remotenavmap'} ne 'on') {
 1470: 		$result.='<td>&nbsp;</td><td>&nbsp;</td><td>&nbsp;</td>'.
 1471: 		    '<td align="right">'.$args->{'sort_html'}.'</td></tr>';
 1472: 	    } else {
 1473: 		$result.='</tr><tr><td align="left"><br />'.
 1474: 		    $args->{'sort_html'}.'</td></tr>';
 1475: 	    }
 1476: 	}
 1477:         $result .= '</table>';
 1478:     } elsif ($args->{'sort_html'}) { 
 1479:         $result.=$args->{'sort_html'}; 
 1480:     }
 1481: 
 1482:     #$result .= "<br />\n";
 1483:     if ($r) {
 1484:         $r->print($result);
 1485:         $r->rflush();
 1486:         $result = "";
 1487:     }
 1488:     # End parameter setting
 1489:     
 1490:     $result .= "<br />\n";
 1491: 
 1492:     # Data
 1493:     $result.=&Apache::loncommon::start_data_table("LC_tableOfContent");    
 1494: 
 1495:     my $res = "Apache::lonnavmaps::resource";
 1496:     my %condenseStatuses =
 1497:         ( $res->NETWORK_FAILURE    => 1,
 1498:           $res->NOTHING_SET        => 1,
 1499:           $res->CORRECT            => 1 );
 1500:     my @backgroundColors = ("LC_trEven", "LC_trOdd");
 1501: 
 1502:     # Shared variables
 1503:     $args->{'counter'} = 0; # counts the rows
 1504:     $args->{'indentLevel'} = 0;
 1505:     $args->{'isNewBranch'} = 0;
 1506:     $args->{'condensed'} = 0;   
 1507: 
 1508:     my $location = &Apache::loncommon::lonhttpdurl("/adm/lonIcons/whitespace_21.gif");
 1509:     $args->{'indentString'} = setDefault($args->{'indentString'}, "<img src='$location' alt='' />");
 1510:     $args->{'displayedHereMarker'} = 0;
 1511: 
 1512:     # If we're suppressing empty sequences, look for them here. Use DFS for speed,
 1513:     # since structure actually doesn't matter, except what map has what resources.
 1514:     if ($args->{'suppressEmptySequences'}) {
 1515:         my $dfsit = Apache::lonnavmaps::DFSiterator->new($navmap,
 1516:                                                          $it->{FIRST_RESOURCE},
 1517:                                                          $it->{FINISH_RESOURCE},
 1518:                                                          {}, undef, 1);
 1519:         my $depth = 0;
 1520:         $dfsit->next();
 1521:         my $curRes = $dfsit->next();
 1522:         while ($depth > -1) {
 1523:             if ($curRes == $dfsit->BEGIN_MAP()) { $depth++; }
 1524:             if ($curRes == $dfsit->END_MAP()) { $depth--; }
 1525: 
 1526:             if (ref($curRes)) { 
 1527:                 # Parallel pre-processing: Do sequences have non-filtered-out children?
 1528:                 if ($curRes->is_map()) {
 1529:                     $curRes->{DATA}->{HAS_VISIBLE_CHILDREN} = 0;
 1530:                     # Sequences themselves do not count as visible children,
 1531:                     # unless those sequences also have visible children.
 1532:                     # This means if a sequence appears, there's a "promise"
 1533:                     # that there's something under it if you open it, somewhere.
 1534:                 } else {
 1535:                     # Not a sequence: if it's filtered, ignore it, otherwise
 1536:                     # rise up the stack and mark the sequences as having children
 1537:                     if (&$filterFunc($curRes)) {
 1538:                         for my $sequence (@{$dfsit->getStack()}) {
 1539:                             $sequence->{DATA}->{HAS_VISIBLE_CHILDREN} = 1;
 1540:                         }
 1541:                     }
 1542:                 }
 1543:             }
 1544:         } continue {
 1545:             $curRes = $dfsit->next();
 1546:         }
 1547:     }
 1548: 
 1549:     my $displayedJumpMarker = 0;
 1550:     # Set up iteration.
 1551:     my $now = time();
 1552:     my $in24Hours = $now + 24 * 60 * 60;
 1553:     my $rownum = 0;
 1554: 
 1555:     # export "here" marker information
 1556:     $args->{'here'} = $here;
 1557: 
 1558:     $args->{'indentLevel'} = -1; # first BEGIN_MAP takes this to 0
 1559:     my @resources;
 1560:     my $code='';# sub { !(shift->is_map();) };
 1561:     if ($args->{'sort'} eq 'title') {
 1562:         my $oldFilterFunc = $filterFunc;
 1563: 	my $filterFunc= 
 1564: 	    sub {
 1565: 		my ($res)=@_;
 1566: 		if ($res->is_map()) { return 0;}
 1567: 		return &$oldFilterFunc($res);
 1568: 	    };
 1569: 	@resources=$navmap->retrieveResources(undef,$filterFunc);
 1570: 	@resources= sort { &cmp_title($a,$b) } @resources;
 1571:     } elsif ($args->{'sort'} eq 'duedate') {
 1572: 	my $oldFilterFunc = $filterFunc;
 1573: 	my $filterFunc= 
 1574: 	    sub {
 1575: 		my ($res)=@_;
 1576: 		if (!$res->is_problem()) { return 0;}
 1577: 		return &$oldFilterFunc($res);
 1578: 	    };
 1579: 	@resources=$navmap->retrieveResources(undef,$filterFunc);
 1580: 	@resources= sort {
 1581: 	    if ($a->duedate ne $b->duedate) {
 1582: 	        return $a->duedate cmp $b->duedate;
 1583: 	    }
 1584: 	    my $value=&cmp_title($a,$b);
 1585: 	    return $value;
 1586: 	} @resources;
 1587:     } elsif ($args->{'sort'} eq 'discussion') {
 1588: 	my $oldFilterFunc = $filterFunc;
 1589: 	my $filterFunc= 
 1590: 	    sub {
 1591: 		my ($res)=@_;
 1592: 		if (!$res->hasDiscussion() &&
 1593: 		    !$res->getFeedback() &&
 1594: 		    !$res->getErrors()) { return 0;}
 1595: 		return &$oldFilterFunc($res);
 1596: 	    };
 1597: 	@resources=$navmap->retrieveResources(undef,$filterFunc);
 1598: 	@resources= sort { &cmp_title($a,$b) } @resources;
 1599:     } else {
 1600: 	#unknow sort mechanism or default
 1601: 	undef($args->{'sort'});
 1602:     }
 1603: 
 1604: 
 1605:     while (1) {
 1606: 	if ($args->{'sort'}) {
 1607: 	    $curRes = shift(@resources);
 1608: 	} else {
 1609: 	    $curRes = $it->next($closeAllPages);
 1610: 	}
 1611: 	if (!$curRes) { last; }
 1612: 
 1613:         # Maintain indentation level.
 1614:         if ($curRes == $it->BEGIN_MAP() ||
 1615:             $curRes == $it->BEGIN_BRANCH() ) {
 1616:             $args->{'indentLevel'}++;
 1617:         }
 1618:         if ($curRes == $it->END_MAP() ||
 1619:             $curRes == $it->END_BRANCH() ) {
 1620:             $args->{'indentLevel'}--;
 1621:         }
 1622:         # Notice new branches
 1623:         if ($curRes == $it->BEGIN_BRANCH()) {
 1624:             $args->{'isNewBranch'} = 1;
 1625:         }
 1626: 
 1627:         # If this isn't an actual resource, continue on
 1628:         if (!ref($curRes)) {
 1629:             next;
 1630:         }
 1631: 
 1632:         # If this has been filtered out, continue on
 1633:         if (!(&$filterFunc($curRes))) {
 1634:             $args->{'isNewBranch'} = 0; # Don't falsely remember this
 1635:             next;
 1636:         } 
 1637: 
 1638:         # If this is an empty sequence and we're filtering them, continue on
 1639:         if ($curRes->is_map() && $args->{'suppressEmptySequences'} &&
 1640:             !$curRes->{DATA}->{HAS_VISIBLE_CHILDREN}) {
 1641:             next;
 1642:         }
 1643: 
 1644:         # If we're suppressing navmaps and this is a navmap, continue on
 1645:         if ($suppressNavmap && $curRes->src() =~ /^\/adm\/navmaps/) {
 1646:             next;
 1647:         }
 1648: 
 1649:         $args->{'counter'}++;
 1650: 
 1651:         # Does it have multiple parts?
 1652:         $args->{'multipart'} = 0;
 1653:         $args->{'condensed'} = 0;
 1654:         my @parts;
 1655:             
 1656:         # Decide what parts to show.
 1657:         if ($curRes->is_problem() && $showParts) {
 1658:             @parts = @{$curRes->parts()};
 1659:             $args->{'multipart'} = $curRes->multipart();
 1660:             
 1661:             if ($condenseParts) { # do the condensation
 1662:                 if (!$args->{'condensed'}) {
 1663:                     # Decide whether to condense based on similarity
 1664:                     my $status = $curRes->status($parts[0]);
 1665:                     my $due = $curRes->duedate($parts[0]);
 1666:                     my $open = $curRes->opendate($parts[0]);
 1667:                     my $statusAllSame = 1;
 1668:                     my $dueAllSame = 1;
 1669:                     my $openAllSame = 1;
 1670:                     for (my $i = 1; $i < scalar(@parts); $i++) {
 1671:                         if ($curRes->status($parts[$i]) != $status){
 1672:                             $statusAllSame = 0;
 1673:                         }
 1674:                         if ($curRes->duedate($parts[$i]) != $due ) {
 1675:                             $dueAllSame = 0;
 1676:                         }
 1677:                         if ($curRes->opendate($parts[$i]) != $open) {
 1678:                             $openAllSame = 0;
 1679:                         }
 1680:                     }
 1681:                     # $*allSame is true if all the statuses were
 1682:                     # the same. Now, if they are all the same and
 1683:                     # match one of the statuses to condense, or they
 1684:                     # are all open with the same due date, or they are
 1685:                     # all OPEN_LATER with the same open date, display the
 1686:                     # status of the first non-zero part (to get the 'correct'
 1687:                     # status right, since 0 is never 'correct' or 'open').
 1688:                     if (($statusAllSame && defined($condenseStatuses{$status})) ||
 1689:                         ($dueAllSame && $status == $curRes->OPEN && $statusAllSame)||
 1690:                         ($openAllSame && $status == $curRes->OPEN_LATER && $statusAllSame) ){
 1691:                         @parts = ($parts[0]);
 1692:                         $args->{'condensed'} = 1;
 1693:                     }
 1694:                 }
 1695: 		# Multipart problem with one part: always "condense" (happens
 1696: 		#  to match the desirable behavior)
 1697: 		if ($curRes->countParts() == 1) {
 1698: 		    @parts = ($parts[0]);
 1699: 		    $args->{'condensed'} = 1;
 1700: 		}
 1701:             }
 1702:         } 
 1703:             
 1704:         # If the multipart problem was condensed, "forget" it was multipart
 1705:         if (scalar(@parts) == 1) {
 1706:             $args->{'multipart'} = 0;
 1707:         } else {
 1708:             # Add part 0 so we display it correctly.
 1709:             unshift @parts, '0';
 1710:         }
 1711: 	
 1712: 	{
 1713: 	    my ($src,$symb,$anchor,$stack);
 1714: 	    if ($args->{'sort'}) {
 1715: 		my $it = $navmap->getIterator(undef, undef, undef, 1);
 1716: 		while ( my $res=$it->next()) {
 1717: 		    if (ref($res) &&
 1718: 			$res->symb() eq  $curRes->symb()) { last; }
 1719: 		}
 1720: 		$stack=$it->getStack();
 1721: 	    } else {
 1722: 		$stack=$it->getStack();
 1723: 	    }
 1724: 	    ($src,$symb,$anchor)=getLinkForResource($stack);
 1725: 	    if (defined($anchor)) { $anchor='#'.$anchor; }
 1726: 	    my $srcHasQuestion = $src =~ /\?/;
 1727: 	    $args->{"resourceLink"} = $src.
 1728: 		($srcHasQuestion?'&':'?') .
 1729: 		'symb=' . &escape($symb).$anchor;
 1730: 	}
 1731:         # Now, we've decided what parts to show. Loop through them and
 1732:         # show them.
 1733:         foreach my $part (@parts) {
 1734:             $rownum ++;
 1735:             my $backgroundColor = $backgroundColors[$rownum % scalar(@backgroundColors)];
 1736:             
 1737:             $result .= &Apache::loncommon::start_data_table_row();
 1738: 
 1739:             # Set up some data about the parts that the cols might want
 1740:             my $filter = $it->{FILTER};
 1741: 
 1742:             # Now, display each column.
 1743:             foreach my $col (@$cols) {
 1744:                 my $colHTML = '';
 1745:                 if (ref($col)) {
 1746:                     $colHTML .= &$col($curRes, $part, $args);
 1747:                 } else {
 1748:                     $colHTML .= &{$preparedColumns[$col]}($curRes, $part, $args);
 1749:                 }
 1750: 
 1751:                 # If this is the first column and it's time to print
 1752:                 # the anchor, do so
 1753:                 if ($col == $cols->[0] && 
 1754:                     $args->{'counter'} == $args->{'currentJumpIndex'} - 
 1755:                     $currentJumpDelta) {
 1756:                     # Jam the anchor after the <td> tag;
 1757:                     # necessary for valid HTML (which Mozilla requires)
 1758:                     $colHTML =~ s/\>/\>\<a name="curloc" \/\>/;
 1759:                     $displayedJumpMarker = 1;
 1760:                 }
 1761:                 $result .= $colHTML . "\n";
 1762:             }
 1763:             $result .= &Apache::loncommon::end_data_table_row();
 1764:             $args->{'isNewBranch'} = 0;
 1765:         }
 1766: 
 1767:         if ($r && $rownum % 20 == 0) {
 1768:             $r->print($result);
 1769:             $result = "";
 1770:             $r->rflush();
 1771:         }
 1772:     } continue {
 1773: 	if ($r) {
 1774: 	    # If we have the connection, make sure the user is still connected
 1775: 	    my $c = $r->connection;
 1776: 	    if ($c->aborted()) {
 1777: 		# Who cares what we do, nobody will see it anyhow.
 1778: 		return '';
 1779: 	    }
 1780: 	}
 1781:     }
 1782:     
 1783:     # Print out the part that jumps to #curloc if it exists
 1784:     # delay needed because the browser is processing the jump before
 1785:     # it finishes rendering, so it goes to the wrong place!
 1786:     # onload might be better, but this routine has no access to that.
 1787:     # On mozilla, the 0-millisecond timeout seems to prevent this;
 1788:     # it's quite likely this might fix other browsers, too, and 
 1789:     # certainly won't hurt anything.
 1790:     if ($displayedJumpMarker) {
 1791:         $result .= "
 1792: <script>
 1793: if (location.href.indexOf('#curloc')==-1) {
 1794:     setTimeout(\"location += '#curloc';\", 0)
 1795: }
 1796: </script>";
 1797:     }
 1798: 
 1799:     $result.=&Apache::loncommon::end_data_table();
 1800: 
 1801:     if ($r) {
 1802:         $r->print($result);
 1803:         $result = "";
 1804:         $r->rflush();
 1805:     }
 1806:         
 1807:     return $result;
 1808: }
 1809: 
 1810: sub add_linkitem {
 1811:     my ($linkitems,$name,$cmd,$text)=@_;
 1812:     $$linkitems{$name}{'cmd'}=$cmd;
 1813:     $$linkitems{$name}{'text'}=&mt($text);
 1814: }
 1815: 
 1816: sub show_linkitems {
 1817:     my ($linkitems)=@_;
 1818:     my @linkorder = ("blank","launchnav","closenav","firsthomework",
 1819: 		     "everything","uncompleted","changefolder","clearbubbles");
 1820:     
 1821:     my $result .= (<<ENDBLOCK);
 1822:               <td align="left">
 1823: <script type="text/javascript">
 1824:     function changeNavDisplay () {
 1825: 	var navchoice = document.linkitems.toplink[document.linkitems.toplink.selectedIndex].value;
 1826: ENDBLOCK
 1827:     foreach my $link (@linkorder) {
 1828: 	$result.= "if (navchoice == '$link') {".
 1829: 	    $linkitems->{$link}{'cmd'}."}\n";
 1830:     }
 1831:     $result.='}
 1832:               </script>
 1833:                    <form name="linkitems" method="post">
 1834:                        <span class="LC_nobreak"><select name="toplink">'."\n";
 1835:     foreach my $link (@linkorder) {
 1836: 	if (defined($linkitems->{$link})) {
 1837: 	    if ($linkitems->{$link}{'text'} ne '') {
 1838: 		$result .= ' <option value="'.$link.'">'.
 1839: 		    $linkitems->{$link}{'text'}."</option>\n";
 1840: 	    }
 1841: 	}
 1842:     }
 1843:     $result .= '</select>&nbsp;<input type="button" name="chgnav"
 1844:                    value="Go" onClick="javascript:changeNavDisplay()" />
 1845:                 </span></form></td>'."\n";
 1846: 	
 1847:     return $result;
 1848: }
 1849: 
 1850: sub show_linkitems_toolbar {
 1851:     my ($linkitems,$condition)=@_;
 1852:     my @linkorder = ("blank","launchnav","closenav","firsthomework",
 1853: 		     "everything","uncompleted","changefolder","clearbubbles");
 1854:     
 1855:     my $result .=' 
 1856:               <td align="left">
 1857:                        <span class="LC_nobreak">'."\n<ul id=\"LC_toolbar\">";
 1858: 	foreach my $link (@linkorder) {
 1859:         my $link_id = "LC_content_toolbar_".$link;
 1860: 	if (defined($linkitems->{$link})) {
 1861: 	    if ($linkitems->{$link}{'text'} ne '') {
 1862: 		$linkitems->{$link}{'cmd'}=~s/"/'/g;
 1863: 		if($linkitems->{$link}{'cmd'}){
 1864:                    if($link eq 'changefolder'){
 1865:                       if($condition){$link_id='LC_content_toolbar_changefolder_toggled'}
 1866:                       else{$link_id='LC_content_toolbar_changefolder'}
 1867:                    }
 1868:                           $result .=  ' <li><a href="#"'.
 1869: 			    	' onClick="'.$linkitems->{$link}{'cmd'}.'"'.
 1870:                                 ' id="'.$link_id.'"'.
 1871:                                 ' class="LC_toolbarItem"'.
 1872: 			   	' title="'.$linkitems->{$link}{'text'}.'"></a></li>'."\n";
 1873: 		}
 1874: 
 1875: 	    }
 1876: 	}
 1877:     }
 1878:     $result .= '</ul>';
 1879:     $result .= ' </span></td>'."\n";
 1880: 	
 1881:     return $result;
 1882: }
 1883: 
 1884: 
 1885: 1;
 1886: 
 1887: 
 1888: 
 1889: 
 1890: 
 1891: 
 1892: 
 1893: 
 1894: 
 1895: package Apache::lonnavmaps::navmap;
 1896: 
 1897: =pod
 1898: 
 1899: =head1 Object: Apache::lonnavmaps::navmap
 1900: 
 1901: =head2 Overview
 1902: 
 1903: The navmap object's job is to provide access to the resources
 1904: in the course as Apache::lonnavmaps::resource objects, and to
 1905: query and manage the relationship between those resource objects.
 1906: 
 1907: Generally, you'll use the navmap object in one of three basic ways.
 1908: In order of increasing complexity and power:
 1909: 
 1910: =over 4
 1911: 
 1912: =item * C<$navmap-E<gt>getByX>, where X is B<Id>, B<Symb> or B<MapPc> and getResourceByUrl. This provides
 1913:     various ways to obtain resource objects, based on various identifiers.
 1914:     Use this when you want to request information about one object or 
 1915:     a handful of resources you already know the identities of, from some
 1916:     other source. For more about Ids, Symbs, and MapPcs, see the
 1917:     Resource documentation. Note that Url should be a B<last resort>,
 1918:     not your first choice; it only really works when there is only one
 1919:     instance of the resource in the course, which only applies to
 1920:     maps, and even that may change in the future (see the B<getResourceByUrl>
 1921:     documentation for more details.)
 1922: 
 1923: =item * C<my @resources = $navmap-E<gt>retrieveResources(args)>. This
 1924:     retrieves resources matching some criterion and returns them
 1925:     in a flat array, with no structure information. Use this when
 1926:     you are manipulating a series of resources, based on what map
 1927:     the are in, but do not care about branching, or exactly how
 1928:     the maps and resources are related. This is the most common case.
 1929: 
 1930: =item * C<$it = $navmap-E<gt>getIterator(args)>. This allows you traverse
 1931:     the course's navmap in various ways without writing the traversal
 1932:     code yourself. See iterator documentation below. Use this when
 1933:     you need to know absolutely everything about the course, including
 1934:     branches and the precise relationship between maps and resources.
 1935: 
 1936: =back
 1937: 
 1938: =head2 Creation And Destruction
 1939: 
 1940: To create a navmap object, use the following function:
 1941: 
 1942: =over 4
 1943: 
 1944: =item * B<Apache::lonnavmaps::navmap-E<gt>new>():
 1945: 
 1946: Creates a new navmap object. Returns the navmap object if this is
 1947: successful, or B<undef> if not.
 1948: 
 1949: =back
 1950: 
 1951: =head2 Methods
 1952: 
 1953: =over 4
 1954: 
 1955: =item * B<getIterator>(first, finish, filter, condition):
 1956: 
 1957: See iterator documentation below.
 1958: 
 1959: =cut
 1960: 
 1961: use strict;
 1962: use GDBM_File;
 1963: use Apache::lonnet;
 1964: use LONCAPA;
 1965: 
 1966: sub new {
 1967:     # magic invocation to create a class instance
 1968:     my $proto = shift;
 1969:     my $class = ref($proto) || $proto;
 1970:     my $self = {};
 1971: 
 1972:     # Resource cache stores navmap resources as we reference them. We generate
 1973:     # them on-demand so we don't pay for creating resources unless we use them.
 1974:     $self->{RESOURCE_CACHE} = {};
 1975: 
 1976:     # Network failure flag, if we accessed the course or user opt and
 1977:     # failed
 1978:     $self->{NETWORK_FAILURE} = 0;
 1979: 
 1980:     # tie the nav hash
 1981: 
 1982:     my %navmaphash;
 1983:     my %parmhash;
 1984:     my $courseFn = $env{"request.course.fn"};
 1985:     if (!(tie(%navmaphash, 'GDBM_File', "${courseFn}.db",
 1986:               &GDBM_READER(), 0640))) {
 1987:         return undef;
 1988:     }
 1989:     
 1990:     if (!(tie(%parmhash, 'GDBM_File', "${courseFn}_parms.db",
 1991:               &GDBM_READER(), 0640)))
 1992:     {
 1993:         untie %{$self->{PARM_HASH}};
 1994:         return undef;
 1995:     }
 1996: 
 1997:     $self->{NAV_HASH} = \%navmaphash;
 1998:     $self->{PARM_HASH} = \%parmhash;
 1999:     $self->{PARM_CACHE} = {};
 2000: 
 2001:     bless($self);
 2002:         
 2003:     return $self;
 2004: }
 2005: 
 2006: sub generate_course_user_opt {
 2007:     my $self = shift;
 2008:     if ($self->{COURSE_USER_OPT_GENERATED}) { return; }
 2009: 
 2010:     my $uname=$env{'user.name'};
 2011:     my $udom=$env{'user.domain'};
 2012:     my $cid=$env{'request.course.id'};
 2013:     my $cdom=$env{'course.'.$cid.'.domain'};
 2014:     my $cnum=$env{'course.'.$cid.'.num'};
 2015:     
 2016: # ------------------------------------------------- Get coursedata (if present)
 2017:     my $courseopt=&Apache::lonnet::get_courseresdata($cnum,$cdom);
 2018:     # Check for network failure
 2019:     if (!ref($courseopt)) {
 2020: 	if ( $courseopt =~ /no.such.host/i || $courseopt =~ /con_lost/i) {
 2021: 	    $self->{NETWORK_FAILURE} = 1;
 2022: 	}
 2023: 	undef($courseopt);
 2024:     }
 2025: 
 2026: # --------------------------------------------------- Get userdata (if present)
 2027: 	
 2028:     my $useropt=&Apache::lonnet::get_userresdata($uname,$udom);
 2029:     # Check for network failure
 2030:     if (!ref($useropt)) {
 2031: 	if ( $useropt =~ /no.such.host/i || $useropt =~ /con_lost/i) {
 2032: 	    $self->{NETWORK_FAILURE} = 1;
 2033: 	}
 2034: 	undef($useropt);
 2035:     }
 2036: 
 2037:     $self->{COURSE_OPT} = $courseopt;
 2038:     $self->{USER_OPT} = $useropt;
 2039: 
 2040:     $self->{COURSE_USER_OPT_GENERATED} = 1;
 2041:     
 2042:     return;
 2043: }
 2044: 
 2045: sub generate_email_discuss_status {
 2046:     my $self = shift;
 2047:     my $symb = shift;
 2048:     if ($self->{EMAIL_DISCUSS_GENERATED}) { return; }
 2049: 
 2050:     my $cid=$env{'request.course.id'};
 2051:     my $cdom=$env{'course.'.$cid.'.domain'};
 2052:     my $cnum=$env{'course.'.$cid.'.num'};
 2053:     
 2054:     my %emailstatus = &Apache::lonnet::dump('email_status');
 2055:     my $logoutTime = $emailstatus{'logout'};
 2056:     my $courseLeaveTime = $emailstatus{'logout_'.$env{'request.course.id'}};
 2057:     $self->{LAST_CHECK} = (($courseLeaveTime > $logoutTime) ?
 2058: 			   $courseLeaveTime : $logoutTime);
 2059:     my %discussiontime = &Apache::lonnet::dump('discussiontimes', 
 2060: 					       $cdom, $cnum);
 2061:     my %lastread = &Apache::lonnet::dump('nohist_'.$cid.'_discuss',
 2062:                                         $env{'user.domain'},$env{'user.name'},'lastread');
 2063:     my %lastreadtime = ();
 2064:     foreach my $key (keys %lastread) {
 2065:         my $shortkey = $key;
 2066:         $shortkey =~ s/_lastread$//;
 2067:         $lastreadtime{$shortkey} = $lastread{$key};
 2068:     }
 2069: 
 2070:     my %feedback=();
 2071:     my %error=();
 2072:     my @keys = &Apache::lonnet::getkeys('nohist_email',$env{'user.domain'},
 2073: 					$env{'user.name'});
 2074:     
 2075:     foreach my $msgid (@keys) {
 2076: 	if ((!$emailstatus{$msgid}) || ($emailstatus{$msgid} eq 'new')) {
 2077:             my ($sendtime,$shortsubj,$fromname,$fromdomain,$status,$fromcid,
 2078:                 $symb,$error) = &Apache::lonmsg::unpackmsgid($msgid);
 2079:             &Apache::lonenc::check_decrypt(\$symb); 
 2080:             if (($fromcid ne '') && ($fromcid ne $cid)) {
 2081:                 next;
 2082:             }
 2083:             if (defined($symb)) {
 2084:                 if (defined($error) && $error == 1) {
 2085:                     $error{$symb}.=','.$msgid;
 2086:                 } else {
 2087:                     $feedback{$symb}.=','.$msgid;
 2088:                 }
 2089:             } else {
 2090:                 my $plain=
 2091:                     &LONCAPA::unescape(&LONCAPA::unescape($msgid));
 2092:                 if ($plain=~/ \[([^\]]+)\]\:/) {
 2093:                     my $url=$1;
 2094:                     if ($plain=~/\:Error \[/) {
 2095:                         $error{$url}.=','.$msgid;
 2096:                     } else {
 2097:                         $feedback{$url}.=','.$msgid;
 2098:                     }
 2099:                 }
 2100:             }
 2101: 	}
 2102:     }
 2103:     
 2104:     #symbs of resources that have feedbacks (will be urls pre-2.3)
 2105:     $self->{FEEDBACK} = \%feedback;
 2106:     #or errors (will be urls pre 2.3)
 2107:     $self->{ERROR_MSG} = \%error;
 2108:     $self->{DISCUSSION_TIME} = \%discussiontime;
 2109:     $self->{EMAIL_STATUS} = \%emailstatus;
 2110:     $self->{LAST_READ} = \%lastreadtime;
 2111:     
 2112:     $self->{EMAIL_DISCUSS_GENERATED} = 1;
 2113: }
 2114: 
 2115: sub get_user_data {
 2116:     my $self = shift;
 2117:     if ($self->{RETRIEVED_USER_DATA}) { return; }
 2118: 
 2119:     # Retrieve performance data on problems
 2120:     my %student_data = Apache::lonnet::currentdump($env{'request.course.id'},
 2121: 						   $env{'user.domain'},
 2122: 						   $env{'user.name'});
 2123:     $self->{STUDENT_DATA} = \%student_data;
 2124: 
 2125:     $self->{RETRIEVED_USER_DATA} = 1;
 2126: }
 2127: 
 2128: sub get_discussion_data {
 2129:     my $self = shift;
 2130:     if ($self->{RETRIEVED_DISCUSSION_DATA}) {
 2131: 	return $self->{DISCUSSION_DATA};
 2132:     }
 2133: 
 2134:     $self->generate_email_discuss_status();    
 2135: 
 2136:     my $cid=$env{'request.course.id'};
 2137:     my $cdom=$env{'course.'.$cid.'.domain'};
 2138:     my $cnum=$env{'course.'.$cid.'.num'};
 2139:     # Retrieve discussion data for resources in course
 2140:     my %discussion_data = &Apache::lonnet::dumpstore($cid,$cdom,$cnum);
 2141: 
 2142: 
 2143:     $self->{DISCUSSION_DATA} = \%discussion_data;
 2144:     $self->{RETRIEVED_DISCUSSION_DATA} = 1;
 2145:     return $self->{DISCUSSION_DATA};
 2146: }
 2147: 
 2148: 
 2149: # Internal function: Takes a key to look up in the nav hash and implements internal
 2150: # memory caching of that key.
 2151: sub navhash {
 2152:     my $self = shift; my $key = shift;
 2153:     return $self->{NAV_HASH}->{$key};
 2154: }
 2155: 
 2156: =pod
 2157: 
 2158: =item * B<courseMapDefined>(): Returns true if the course map is defined, 
 2159:     false otherwise. Undefined course maps indicate an error somewhere in
 2160:     LON-CAPA, and you will not be able to proceed with using the navmap.
 2161:     See the B<NAV> screen for an example of using this.
 2162: 
 2163: =cut
 2164: 
 2165: # Checks to see if coursemap is defined, matching test in old lonnavmaps
 2166: sub courseMapDefined {
 2167:     my $self = shift;
 2168:     my $uri = &Apache::lonnet::clutter($env{'request.course.uri'});
 2169: 
 2170:     my $firstres = $self->navhash("map_start_$uri");
 2171:     my $lastres = $self->navhash("map_finish_$uri");
 2172:     return $firstres && $lastres;
 2173: }
 2174: 
 2175: sub getIterator {
 2176:     my $self = shift;
 2177:     my $iterator = Apache::lonnavmaps::iterator->new($self, shift, shift,
 2178:                                                      shift, undef, shift,
 2179: 						     shift, shift);
 2180:     return $iterator;
 2181: }
 2182: 
 2183: # Private method: Does the given resource (as a symb string) have
 2184: # current discussion? Returns 0 if chat/mail data not extracted.
 2185: sub hasDiscussion {
 2186:     my $self = shift;
 2187:     my $symb = shift;
 2188:     $self->generate_email_discuss_status();
 2189: 
 2190:     if (!defined($self->{DISCUSSION_TIME})) { return 0; }
 2191: 
 2192:     #return defined($self->{DISCUSSION_TIME}->{$symb});
 2193: 
 2194:     # backward compatibility (bulletin boards used to be 'wrapped')
 2195:     my $ressymb = $self->wrap_symb($symb);
 2196:     if ( defined ( $self->{LAST_READ}->{$ressymb} ) ) {
 2197:         return $self->{DISCUSSION_TIME}->{$ressymb} > $self->{LAST_READ}->{$ressymb};
 2198:     } else {
 2199: #        return $self->{DISCUSSION_TIME}->{$ressymb} >  $self->{LAST_CHECK}; # v.1.1 behavior 
 2200:         return $self->{DISCUSSION_TIME}->{$ressymb} >  0; # in 1.2 will display speech bubble icons for all items with posts until marked as read (even if read in v 1.1).
 2201:     }
 2202: }
 2203: 
 2204: sub last_post_time {
 2205:     my $self = shift;
 2206:     my $symb = shift;
 2207:     my $ressymb = $self->wrap_symb($symb);
 2208:     return $self->{DISCUSSION_TIME}->{$ressymb};
 2209: }
 2210: 
 2211: sub discussion_info {
 2212:     my $self = shift;
 2213:     my $symb = shift;
 2214:     my $filter = shift;
 2215: 
 2216:     $self->get_discussion_data();
 2217: 
 2218:     my $ressymb = $self->wrap_symb($symb);
 2219:     # keys used to store bulletinboard postings use 'unwrapped' symb. 
 2220:     my $discsymb = &escape($self->unwrap_symb($ressymb));
 2221:     my $version = $self->{DISCUSSION_DATA}{'version:'.$discsymb};
 2222:     if (!$version) { return; }
 2223: 
 2224:     my $prevread = $self->{LAST_READ}{$ressymb};
 2225: 
 2226:     my $count = 0;
 2227:     my $hiddenflag = 0;
 2228:     my $deletedflag = 0;
 2229:     my ($hidden,$deleted,%info);
 2230: 
 2231:     for (my $id=$version; $id>0; $id--) {
 2232: 	my $vkeys=$self->{DISCUSSION_DATA}{$id.':keys:'.$discsymb};
 2233: 	my @keys=split(/:/,$vkeys);
 2234: 	if (grep(/^hidden$/ ,@keys)) {
 2235: 	    if (!$hiddenflag) {
 2236: 		$hidden = $self->{DISCUSSION_DATA}{$id.':'.$discsymb.':hidden'};
 2237: 		$hiddenflag = 1;
 2238: 	    }
 2239: 	} elsif (grep(/^deleted$/,@keys)) {
 2240: 	    if (!$deletedflag) {
 2241: 		$deleted = $self->{DISCUSSION_DATA}{$id.':'.$discsymb.':deleted'};
 2242: 		$deletedflag = 1;
 2243: 	    }
 2244: 	} else {
 2245: 	    if (($hidden !~/\.$id\./) && ($deleted !~/\.$id\./)) {
 2246:                 if ($filter eq 'unread') {
 2247: 		    if ($prevread >= $self->{DISCUSSION_DATA}{$id.':'.$discsymb.':timestamp'}) {
 2248:                         next;
 2249:                     }
 2250:                 }
 2251: 		$count++;
 2252: 		$info{$count}{'subject'} =
 2253: 		    $self->{DISCUSSION_DATA}{$id.':'.$discsymb.':subject'};
 2254:                 $info{$count}{'id'} = $id;
 2255:                 $info{$count}{'timestamp'} = $self->{DISCUSSION_DATA}{$id.':'.$discsymb.':timestamp'};
 2256:             }
 2257: 	}
 2258:     }
 2259:     if (wantarray) {
 2260: 	return ($count,%info);
 2261:     }
 2262:     return $count;
 2263: }
 2264: 
 2265: sub wrap_symb {
 2266:     my $self = shift;
 2267:     my $symb = shift;
 2268:     if ($symb =~ m-___(adm/[^/]+/[^/]+/)(\d+)(/bulletinboard)$-) {
 2269:         unless ($symb =~ m|adm/wrapper/adm|) {
 2270:             $symb = 'bulletin___'.$2.'___adm/wrapper/'.$1.$2.$3;
 2271:         }
 2272:     }
 2273:     return $symb;
 2274: }
 2275: 
 2276: sub unwrap_symb {
 2277:     my $self = shift;
 2278:     my $ressymb = shift;
 2279:     my $discsymb = $ressymb;
 2280:     if ($ressymb =~ m-^(bulletin___\d+___)adm/wrapper/(adm/[^/]+/[^/]+/\d+/bulletinboard)$-) {
 2281:          $discsymb = $1.$2;
 2282:     }
 2283:     return $discsymb;
 2284: }
 2285: 
 2286: # Private method: Does the given resource (as a symb string) have
 2287: # current feedback? Returns the string in the feedback hash, which
 2288: # will be false if it does not exist.
 2289: 
 2290: sub getFeedback { 
 2291:     my $self = shift;
 2292:     my $symb = shift;
 2293:     my $source = shift;
 2294: 
 2295:     $self->generate_email_discuss_status();
 2296: 
 2297:     if (!defined($self->{FEEDBACK})) { return ""; }
 2298:     
 2299:     my $feedback;
 2300:     if ($self->{FEEDBACK}->{$symb}) {
 2301:         $feedback = $self->{FEEDBACK}->{$symb};
 2302:         if ($self->{FEEDBACK}->{$source}) {
 2303:             $feedback .= ','.$self->{FEEDBACK}->{$source};
 2304:         }
 2305:     } else {
 2306:         if ($self->{FEEDBACK}->{$source}) {
 2307:             $feedback = $self->{FEEDBACK}->{$source};
 2308:         }
 2309:     }
 2310:     return $feedback;
 2311: }
 2312: 
 2313: # Private method: Get the errors for that resource (by source).
 2314: sub getErrors { 
 2315:     my $self = shift;
 2316:     my $symb = shift;
 2317:     my $src = shift;
 2318: 
 2319:     $self->generate_email_discuss_status();
 2320: 
 2321:     if (!defined($self->{ERROR_MSG})) { return ""; }
 2322: 
 2323:     my $errors;
 2324:     if ($self->{ERROR_MSG}->{$symb}) {
 2325:         $errors = $self->{ERROR_MSG}->{$symb};
 2326:         if ($self->{ERROR_MSG}->{$src}) {
 2327:             $errors .= ','.$self->{ERROR_MSG}->{$src};
 2328:         }
 2329:     } else {
 2330:         if ($self->{ERROR_MSG}->{$src}) {
 2331:             $errors = $self->{ERROR_MSG}->{$src};
 2332:         }
 2333:     }
 2334:     return $errors;
 2335: }
 2336: 
 2337: =pod
 2338: 
 2339: =item * B<getById>(id):
 2340: 
 2341: Based on the ID of the resource (1.1, 3.2, etc.), get a resource
 2342: object for that resource. This method, or other methods that use it
 2343: (as in the resource object) is the only proper way to obtain a
 2344: resource object.
 2345: 
 2346: =item * B<getBySymb>(symb):
 2347: 
 2348: Based on the symb of the resource, get a resource object for that
 2349: resource. This is one of the proper ways to get a resource object.
 2350: 
 2351: =item * B<getMapByMapPc>(map_pc):
 2352: 
 2353: Based on the map_pc of the resource, get a resource object for
 2354: the given map. This is one of the proper ways to get a resource object.
 2355: 
 2356: =cut
 2357: 
 2358: # The strategy here is to cache the resource objects, and only construct them
 2359: # as we use them. The real point is to prevent reading any more from the tied
 2360: # hash than we have to, which should hopefully alleviate speed problems.
 2361: 
 2362: sub getById {
 2363:     my $self = shift;
 2364:     my $id = shift;
 2365: 
 2366:     if (defined ($self->{RESOURCE_CACHE}->{$id}))
 2367:     {
 2368:         return $self->{RESOURCE_CACHE}->{$id};
 2369:     }
 2370: 
 2371:     # resource handles inserting itself into cache.
 2372:     # Not clear why the quotes are necessary, but as of this
 2373:     # writing it doesn't work without them.
 2374:     return "Apache::lonnavmaps::resource"->new($self, $id);
 2375: }
 2376: 
 2377: sub getBySymb {
 2378:     my $self = shift;
 2379:     my $symb = shift;
 2380: 
 2381:     my ($mapUrl, $id, $filename) = &Apache::lonnet::decode_symb($symb);
 2382:     my $map = $self->getResourceByUrl($mapUrl);
 2383:     my $returnvalue = undef;
 2384:     if (ref($map)) {
 2385:         $returnvalue = $self->getById($map->map_pc() .'.'.$id);
 2386:     }
 2387:     return $returnvalue;
 2388: }
 2389: 
 2390: sub getByMapPc {
 2391:     my $self = shift;
 2392:     my $map_pc = shift;
 2393:     my $map_id = $self->{NAV_HASH}->{'map_id_' . $map_pc};
 2394:     $map_id = $self->{NAV_HASH}->{'ids_' . $map_id};
 2395:     return $self->getById($map_id);
 2396: }
 2397: 
 2398: =pod
 2399: 
 2400: =item * B<firstResource>():
 2401: 
 2402: Returns a resource object reference corresponding to the first
 2403: resource in the navmap.
 2404: 
 2405: =cut
 2406: 
 2407: sub firstResource {
 2408:     my $self = shift;
 2409:     my $firstResource = $self->navhash('map_start_' .
 2410:                      &Apache::lonnet::clutter($env{'request.course.uri'}));
 2411:     return $self->getById($firstResource);
 2412: }
 2413: 
 2414: =pod
 2415: 
 2416: =item * B<finishResource>():
 2417: 
 2418: Returns a resource object reference corresponding to the last resource
 2419: in the navmap.
 2420: 
 2421: =cut
 2422: 
 2423: sub finishResource {
 2424:     my $self = shift;
 2425:     my $firstResource = $self->navhash('map_finish_' .
 2426:                      &Apache::lonnet::clutter($env{'request.course.uri'}));
 2427:     return $self->getById($firstResource);
 2428: }
 2429: 
 2430: # Parmval reads the parm hash and cascades the lookups. parmval_real does
 2431: # the actual lookup; parmval caches the results.
 2432: sub parmval {
 2433:     my $self = shift;
 2434:     my ($what,$symb,$recurse)=@_;
 2435:     my $hashkey = $what."|||".$symb;
 2436: 
 2437:     if (defined($self->{PARM_CACHE}->{$hashkey})) {
 2438:         if (ref($self->{PARM_CACHE}->{$hashkey}) eq 'ARRAY') { 
 2439:             if (defined($self->{PARM_CACHE}->{$hashkey}->[0])) {
 2440:                 if (wantarray) {
 2441:                     return @{$self->{PARM_CACHE}->{$hashkey}};
 2442:                 } else {
 2443:                     return $self->{PARM_CACHE}->{$hashkey}->[0];
 2444:                 }
 2445:             }
 2446:         } else {
 2447:             return $self->{PARM_CACHE}->{$hashkey};
 2448:         }
 2449:     }
 2450:     my $result = $self->parmval_real($what, $symb, $recurse);
 2451:     $self->{PARM_CACHE}->{$hashkey} = $result;
 2452:     if (wantarray) {
 2453:         return @{$result};
 2454:     }
 2455:     return $result->[0];
 2456: }
 2457: 
 2458: sub parmval_real {
 2459:     my $self = shift;
 2460:     my ($what,$symb,$recurse) = @_;
 2461: 
 2462:     # Make sure the {USER_OPT} and {COURSE_OPT} hashes are populated
 2463:     $self->generate_course_user_opt();
 2464: 
 2465:     my $cid=$env{'request.course.id'};
 2466:     my $csec=$env{'request.course.sec'};
 2467:     my $cgroup='';
 2468:     my @cgrps=split(/:/,$env{'request.course.groups'});
 2469:     if (@cgrps > 0) {
 2470:         @cgrps = sort(@cgrps);
 2471:         $cgroup = $cgrps[0];
 2472:     } 
 2473:     my $uname=$env{'user.name'};
 2474:     my $udom=$env{'user.domain'};
 2475: 
 2476:     unless ($symb) { return ['']; }
 2477:     my $result='';
 2478: 
 2479:     my ($mapname,$id,$fn)=&Apache::lonnet::decode_symb($symb);
 2480:     $mapname = &Apache::lonnet::deversion($mapname);
 2481: # ----------------------------------------------------- Cascading lookup scheme
 2482:     my $rwhat=$what;
 2483:     $what=~s/^parameter\_//;
 2484:     $what=~s/\_/\./;
 2485: 
 2486:     my $symbparm=$symb.'.'.$what;
 2487:     my $mapparm=$mapname.'___(all).'.$what;
 2488:     my $usercourseprefix=$cid;
 2489: 
 2490:     my $grplevel=$usercourseprefix.'.['.$cgroup.'].'.$what;
 2491:     my $grplevelr=$usercourseprefix.'.['.$cgroup.'].'.$symbparm;
 2492:     my $grplevelm=$usercourseprefix.'.['.$cgroup.'].'.$mapparm;
 2493: 
 2494:     my $seclevel= $usercourseprefix.'.['.$csec.'].'.$what;
 2495:     my $seclevelr=$usercourseprefix.'.['.$csec.'].'.$symbparm;
 2496:     my $seclevelm=$usercourseprefix.'.['.$csec.'].'.$mapparm;
 2497: 
 2498:     my $courselevel= $usercourseprefix.'.'.$what;
 2499:     my $courselevelr=$usercourseprefix.'.'.$symbparm;
 2500:     my $courselevelm=$usercourseprefix.'.'.$mapparm;
 2501: 
 2502:     my $useropt = $self->{USER_OPT};
 2503:     my $courseopt = $self->{COURSE_OPT};
 2504:     my $parmhash = $self->{PARM_HASH};
 2505: 
 2506: # ---------------------------------------------------------- first, check user
 2507:     if ($uname and defined($useropt)) {
 2508:         if (defined($$useropt{$courselevelr})) { return [$$useropt{$courselevelr},'resource']; }
 2509:         if (defined($$useropt{$courselevelm})) { return [$$useropt{$courselevelm},'map']; }
 2510:         if (defined($$useropt{$courselevel})) { return [$$useropt{$courselevel},'course']; }
 2511:     }
 2512: 
 2513: # ------------------------------------------------------- second, check course
 2514:     if ($cgroup ne '' and defined($courseopt)) {
 2515:         if (defined($$courseopt{$grplevelr})) { return [$$courseopt{$grplevelr},'resource']; }
 2516:         if (defined($$courseopt{$grplevelm})) { return [$$courseopt{$grplevelm},'map']; }
 2517:         if (defined($$courseopt{$grplevel})) { return [$$courseopt{$grplevel},'course']; }
 2518:     }
 2519: 
 2520:     if ($csec and defined($courseopt)) {
 2521:         if (defined($$courseopt{$seclevelr})) { return [$$courseopt{$seclevelr},'resource']; }
 2522:         if (defined($$courseopt{$seclevelm})) { return [$$courseopt{$seclevelm},'map']; }
 2523:         if (defined($$courseopt{$seclevel})) { return [$$courseopt{$seclevel},'course']; }
 2524:     }
 2525: 
 2526:     if (defined($courseopt)) {
 2527:         if (defined($$courseopt{$courselevelr})) { return [$$courseopt{$courselevelr},'resource']; }
 2528:     }
 2529: 
 2530: # ----------------------------------------------------- third, check map parms
 2531: 
 2532:     my $thisparm=$$parmhash{$symbparm};
 2533:     if (defined($thisparm)) { return [$thisparm,'map']; }
 2534: 
 2535: # ----------------------------------------------------- fourth , check default
 2536: 
 2537:     my $meta_rwhat=$rwhat;
 2538:     $meta_rwhat=~s/\./_/g;
 2539:     my $default=&Apache::lonnet::metadata($fn,$meta_rwhat);
 2540:     if (defined($default)) { return [$default,'resource']}
 2541:     $default=&Apache::lonnet::metadata($fn,'parameter_'.$meta_rwhat);
 2542:     if (defined($default)) { return [$default,'resource']}
 2543: # --------------------------------------------------- fifth, check more course
 2544:     if (defined($courseopt)) {
 2545:         if (defined($$courseopt{$courselevelm})) { return [$$courseopt{$courselevelm},'map']; }
 2546:         if (defined($$courseopt{$courselevel})) {
 2547:            my $ret = [$$courseopt{$courselevel},'course'];
 2548:            return $ret;
 2549:        }
 2550:     }
 2551: # --------------------------------------------------- sixth , cascade up parts
 2552: 
 2553:     my ($space,@qualifier)=split(/\./,$rwhat);
 2554:     my $qualifier=join('.',@qualifier);
 2555:     unless ($space eq '0') {
 2556: 	my @parts=split(/_/,$space);
 2557: 	my $id=pop(@parts);
 2558: 	my $part=join('_',@parts);
 2559: 	if ($part eq '') { $part='0'; }
 2560:        my @partgeneral=$self->parmval($part.".$qualifier",$symb,1);
 2561:        if (defined($partgeneral[0])) { return \@partgeneral; }
 2562:     }
 2563:     if ($recurse) { return []; }
 2564:     my $pack_def=&Apache::lonnet::packages_tab_default($fn,'resource.'.$rwhat);
 2565:     if (defined($pack_def)) { return [$pack_def,'resource']; }
 2566:     return [''];
 2567: }
 2568: 
 2569: =pod
 2570: 
 2571: =item * B<getResourceByUrl>(url,multiple):
 2572: 
 2573: Retrieves a resource object by URL of the resource, unless the optional
 2574: multiple parameter is included in which case an array of resource 
 2575: objects is returned. If passed a resource object, it will simply return  
 2576: it, so it is safe to use this method in code like
 2577: "$res = $navmap->getResourceByUrl($res)"
 2578: if you're not sure if $res is already an object, or just a URL. If the
 2579: resource appears multiple times in the course, only the first instance 
 2580: will be returned (useful for maps), unless the multiple parameter has
 2581: been included, in which case all instances are returned in an array.
 2582: 
 2583: =item * B<retrieveResources>(map, filterFunc, recursive, bailout, showall):
 2584: 
 2585: The map is a specification of a map to retreive the resources from,
 2586: either as a url or as an object. The filterFunc is a reference to a
 2587: function that takes a resource object as its one argument and returns
 2588: true if the resource should be included, or false if it should not
 2589: be. If recursive is true, the map will be recursively examined,
 2590: otherwise it will not be. If bailout is true, the function will return
 2591: as soon as it finds a resource, if false it will finish. If showall is
 2592: true it will not hide maps that contain nothing but one other map. By
 2593: default, the map is the top-level map of the course, filterFunc is a
 2594: function that always returns 1, recursive is true, bailout is false,
 2595: showall is false. The resources will be returned in a list containing
 2596: the resource objects for the corresponding resources, with B<no
 2597: structure information> in the list; regardless of branching,
 2598: recursion, etc., it will be a flat list.
 2599: 
 2600: Thus, this is suitable for cases where you don't want the structure,
 2601: just a list of all resources. It is also suitable for finding out how
 2602: many resources match a given description; for this use, if all you
 2603: want to know is if I<any> resources match the description, the bailout
 2604: parameter will allow you to avoid potentially expensive enumeration of
 2605: all matching resources.
 2606: 
 2607: =item * B<hasResource>(map, filterFunc, recursive, showall):
 2608: 
 2609: Convenience method for
 2610: 
 2611:  scalar(retrieveResources($map, $filterFunc, $recursive, 1, $showall)) > 0
 2612: 
 2613: which will tell whether the map has resources matching the description
 2614: in the filter function.
 2615: 
 2616: =item * B<usedVersion>(url):
 2617: 
 2618: Retrieves version infomation for a url. Returns the version (a number, or 
 2619: the string "mostrecent") for resources which have version information in  
 2620: the big hash.
 2621:     
 2622: =cut
 2623: 
 2624: 
 2625: sub getResourceByUrl {
 2626:     my $self = shift;
 2627:     my $resUrl = shift;
 2628:     my $multiple = shift;
 2629: 
 2630:     if (ref($resUrl)) { return $resUrl; }
 2631: 
 2632:     $resUrl = &Apache::lonnet::clutter($resUrl);
 2633:     my $resId = $self->{NAV_HASH}->{'ids_' . $resUrl};
 2634:     if (!$resId) { return ''; }
 2635:     if ($multiple) {
 2636:         my @resources = ();
 2637:         my @resIds = split (/,/, $resId);
 2638:         foreach my $id (@resIds) {
 2639:             my $resourceId = $self->getById($id);
 2640:             if ($resourceId) { 
 2641:                 push(@resources,$resourceId);
 2642:             }
 2643:         }
 2644:         return @resources;
 2645:     } else {
 2646:         if ($resId =~ /,/) {
 2647:             $resId = (split (/,/, $resId))[0];
 2648:         }
 2649:         return $self->getById($resId);
 2650:     }
 2651: }
 2652: 
 2653: sub retrieveResources {
 2654:     my $self = shift;
 2655:     my $map = shift;
 2656:     my $filterFunc = shift;
 2657:     if (!defined ($filterFunc)) {
 2658:         $filterFunc = sub {return 1;};
 2659:     }
 2660:     my $recursive = shift;
 2661:     if (!defined($recursive)) { $recursive = 1; }
 2662:     my $bailout = shift;
 2663:     if (!defined($bailout)) { $bailout = 0; }
 2664:     my $showall = shift;
 2665:     # Create the necessary iterator.
 2666:     if (!ref($map)) { # assume it's a url of a map.
 2667:         $map = $self->getResourceByUrl($map);
 2668:     }
 2669: 
 2670:     # If nothing was passed, assume top-level map
 2671:     if (!$map) {
 2672: 	$map = $self->getById('0.0');
 2673:     }
 2674: 
 2675:     # Check the map's validity.
 2676:     if (!$map->is_map()) {
 2677:         # Oh, to throw an exception.... how I'd love that!
 2678:         return ();
 2679:     }
 2680: 
 2681:     # Get an iterator.
 2682:     my $it = $self->getIterator($map->map_start(), $map->map_finish(),
 2683:                                 undef, $recursive, $showall);
 2684: 
 2685:     my @resources = ();
 2686: 
 2687:     if (&$filterFunc($map)) {
 2688: 	push(@resources, $map);
 2689:     }
 2690: 
 2691:     # Run down the iterator and collect the resources.
 2692:     my $curRes;
 2693: 
 2694:     while ($curRes = $it->next()) {
 2695:         if (ref($curRes)) {
 2696:             if (!&$filterFunc($curRes)) {
 2697:                 next;
 2698:             }
 2699: 
 2700:             push(@resources, $curRes);
 2701: 
 2702:             if ($bailout) {
 2703:                 return @resources;
 2704:             }
 2705:         }
 2706: 
 2707:     }
 2708: 
 2709:     return @resources;
 2710: }
 2711: 
 2712: sub hasResource {
 2713:     my $self = shift;
 2714:     my $map = shift;
 2715:     my $filterFunc = shift;
 2716:     my $recursive = shift;
 2717:     my $showall = shift;
 2718:     
 2719:     return scalar($self->retrieveResources($map, $filterFunc, $recursive, 1, $showall)) > 0;
 2720: }
 2721: 
 2722: sub usedVersion {
 2723:     my $self = shift;
 2724:     my $linkurl = shift;
 2725:     return $self->navhash("version_$linkurl");
 2726: }
 2727: 
 2728: 1;
 2729: 
 2730: package Apache::lonnavmaps::iterator;
 2731: use Scalar::Util qw(weaken);
 2732: use Apache::lonnet;
 2733: 
 2734: =pod
 2735: 
 2736: =back
 2737: 
 2738: =head1 Object: navmap Iterator
 2739: 
 2740: An I<iterator> encapsulates the logic required to traverse a data
 2741: structure. navmap uses an iterator to traverse the course map
 2742: according to the criteria you wish to use.
 2743: 
 2744: To obtain an iterator, call the B<getIterator>() function of a
 2745: B<navmap> object. (Do not instantiate Apache::lonnavmaps::iterator
 2746: directly.) This will return a reference to the iterator:
 2747: 
 2748: C<my $resourceIterator = $navmap-E<gt>getIterator();>
 2749: 
 2750: To get the next thing from the iterator, call B<next>:
 2751: 
 2752: C<my $nextThing = $resourceIterator-E<gt>next()>
 2753: 
 2754: getIterator behaves as follows:
 2755: 
 2756: =over 4
 2757: 
 2758: =item * B<getIterator>(firstResource, finishResource, filterHash, condition, forceTop, returnTopMap):
 2759: 
 2760: All parameters are optional. firstResource is a resource reference
 2761: corresponding to where the iterator should start. It defaults to
 2762: navmap->firstResource() for the corresponding nav map. finishResource
 2763: corresponds to where you want the iterator to end, defaulting to
 2764: navmap->finishResource(). filterHash is a hash used as a set
 2765: containing strings representing the resource IDs, defaulting to
 2766: empty. Condition is a 1 or 0 that sets what to do with the filter
 2767: hash: If a 0, then only resources that exist IN the filterHash will be
 2768: recursed on. If it is a 1, only resources NOT in the filterHash will
 2769: be recursed on. Defaults to 0. forceTop is a boolean value. If it is
 2770: false (default), the iterator will only return the first level of map
 2771: that is not just a single, 'redirecting' map. If true, the iterator
 2772: will return all information, starting with the top-level map,
 2773: regardless of content. returnTopMap, if true (default false), will
 2774: cause the iterator to return the top-level map object (resource 0.0)
 2775: before anything else.
 2776: 
 2777: Thus, by default, only top-level resources will be shown. Change the
 2778: condition to a 1 without changing the hash, and all resources will be
 2779: shown. Changing the condition to 1 and including some values in the
 2780: hash will allow you to selectively suppress parts of the navmap, while
 2781: leaving it on 0 and adding things to the hash will allow you to
 2782: selectively add parts of the nav map. See the handler code for
 2783: examples.
 2784: 
 2785: The iterator will return either a reference to a resource object, or a
 2786: token representing something in the map, such as the beginning of a
 2787: new branch. The possible tokens are:
 2788: 
 2789: =over 4
 2790: 
 2791: =item * B<END_ITERATOR>:
 2792: 
 2793: The iterator has returned all that it's going to. Further calls to the
 2794: iterator will just produce more of these. This is a "false" value, and
 2795: is the only false value the iterator which will be returned, so it can
 2796: be used as a loop sentinel.
 2797: 
 2798: =item * B<BEGIN_MAP>:
 2799: 
 2800: A new map is being recursed into. This is returned I<after> the map
 2801: resource itself is returned.
 2802: 
 2803: =item * B<END_MAP>:
 2804: 
 2805: The map is now done.
 2806: 
 2807: =item * B<BEGIN_BRANCH>:
 2808: 
 2809: A branch is now starting. The next resource returned will be the first
 2810: in that branch.
 2811: 
 2812: =item * B<END_BRANCH>:
 2813: 
 2814: The branch is now done.
 2815: 
 2816: =back
 2817: 
 2818: The tokens are retreivable via methods on the iterator object, i.e.,
 2819: $iterator->END_MAP.
 2820: 
 2821: Maps can contain empty resources. The iterator will automatically skip
 2822: over such resources, but will still treat the structure
 2823: correctly. Thus, a complicated map with several branches, but
 2824: consisting entirely of empty resources except for one beginning or
 2825: ending resource, will cause a lot of BRANCH_STARTs and BRANCH_ENDs,
 2826: but only one resource will be returned.
 2827: 
 2828: =back
 2829: 
 2830: =head2 Normal Usage
 2831: 
 2832: Normal usage of the iterator object is to do the following:
 2833: 
 2834:  my $it = $navmap->getIterator([your params here]);
 2835:  my $curRes;
 2836:  while ($curRes = $it->next()) {
 2837:    [your logic here]
 2838:  }
 2839: 
 2840: Note that inside of the loop, it's frequently useful to check if
 2841: "$curRes" is a reference or not with the reference function; only
 2842: resource objects will be references, and any non-references will 
 2843: be the tokens described above.
 2844: 
 2845: Also note there is some old code floating around that trys to track
 2846: the depth of the iterator to see when it's done; do not copy that 
 2847: code. It is difficult to get right and harder to understand than
 2848: this. They should be migrated to this new style.
 2849: 
 2850: =cut
 2851: 
 2852: # Here are the tokens for the iterator:
 2853: 
 2854: sub END_ITERATOR { return 0; }
 2855: sub BEGIN_MAP { return 1; }    # begining of a new map
 2856: sub END_MAP { return 2; }      # end of the map
 2857: sub BEGIN_BRANCH { return 3; } # beginning of a branch
 2858: sub END_BRANCH { return 4; }   # end of a branch
 2859: sub FORWARD { return 1; }      # go forward
 2860: sub BACKWARD { return 2; }
 2861: 
 2862: sub min {
 2863:     (my $a, my $b) = @_;
 2864:     if ($a < $b) { return $a; } else { return $b; }
 2865: }
 2866: 
 2867: sub new {
 2868:     # magic invocation to create a class instance
 2869:     my $proto = shift;
 2870:     my $class = ref($proto) || $proto;
 2871:     my $self = {};
 2872: 
 2873:     weaken($self->{NAV_MAP} = shift);
 2874:     return undef unless ($self->{NAV_MAP});
 2875: 
 2876:     # Handle the parameters
 2877:     $self->{FIRST_RESOURCE} = shift || $self->{NAV_MAP}->firstResource();
 2878:     $self->{FINISH_RESOURCE} = shift || $self->{NAV_MAP}->finishResource();
 2879: 
 2880:     # If the given resources are just the ID of the resource, get the
 2881:     # objects
 2882:     if (!ref($self->{FIRST_RESOURCE})) { $self->{FIRST_RESOURCE} = 
 2883:              $self->{NAV_MAP}->getById($self->{FIRST_RESOURCE}); }
 2884:     if (!ref($self->{FINISH_RESOURCE})) { $self->{FINISH_RESOURCE} = 
 2885:              $self->{NAV_MAP}->getById($self->{FINISH_RESOURCE}); }
 2886: 
 2887:     $self->{FILTER} = shift;
 2888: 
 2889:     # A hash, used as a set, of resource already seen
 2890:     $self->{ALREADY_SEEN} = shift;
 2891:     if (!defined($self->{ALREADY_SEEN})) { $self->{ALREADY_SEEN} = {} };
 2892:     $self->{CONDITION} = shift;
 2893: 
 2894:     # Do we want to automatically follow "redirection" maps?
 2895:     $self->{FORCE_TOP} = shift;
 2896: 
 2897:     # Do we want to return the top-level map object (resource 0.0)?
 2898:     $self->{RETURN_0} = shift;
 2899:     # have we done that yet?
 2900:     $self->{HAVE_RETURNED_0} = 0;
 2901: 
 2902:     # Now, we need to pre-process the map, by walking forward and backward
 2903:     # over the parts of the map we're going to look at.
 2904: 
 2905:     # The processing steps are exactly the same, except for a few small 
 2906:     # changes, so I bundle those up in the following list of two elements:
 2907:     # (direction_to_iterate, VAL_name, next_resource_method_to_call,
 2908:     # first_resource).
 2909:     # This prevents writing nearly-identical code twice.
 2910:     my @iterations = ( [FORWARD(), 'TOP_DOWN_VAL', 'getNext', 
 2911:                         'FIRST_RESOURCE'],
 2912:                        [BACKWARD(), 'BOT_UP_VAL', 'getPrevious', 
 2913:                         'FINISH_RESOURCE'] );
 2914: 
 2915:     my $maxDepth = 0; # tracks max depth
 2916: 
 2917:     # If there is only one resource in this map, and it's a map, we
 2918:     # want to remember that, so the user can ask for the first map
 2919:     # that isn't just a redirector.
 2920:     my $resource; my $resourceCount = 0;
 2921: 
 2922:     # Documentation on this algorithm can be found in the CVS repository at 
 2923:     # /docs/lonnavdocs; these "**#**" markers correspond to documentation
 2924:     # in that file.
 2925:     # **1**
 2926: 
 2927:     foreach my $pass (@iterations) {
 2928:         my $direction = $pass->[0];
 2929:         my $valName = $pass->[1];
 2930:         my $nextResourceMethod = $pass->[2];
 2931:         my $firstResourceName = $pass->[3];
 2932: 
 2933:         my $iterator = Apache::lonnavmaps::DFSiterator->new($self->{NAV_MAP}, 
 2934:                                                             $self->{FIRST_RESOURCE},
 2935:                                                             $self->{FINISH_RESOURCE},
 2936:                                                             {}, undef, 0, $direction);
 2937:     
 2938:         # prime the recursion
 2939:         $self->{$firstResourceName}->{DATA}->{$valName} = 0;
 2940: 	$iterator->next();
 2941:         my $curRes = $iterator->next();
 2942: 	my $depth = 1;
 2943:         while ($depth > 0) {
 2944: 	    if ($curRes == $iterator->BEGIN_MAP()) { $depth++; }
 2945: 	    if ($curRes == $iterator->END_MAP()) { $depth--; }
 2946: 
 2947:             if (ref($curRes)) {
 2948:                 # If there's only one resource, this will save it
 2949:                 # we have to filter empty resources from consideration here,
 2950:                 # or even "empty", redirecting maps have two (start & finish)
 2951:                 # or three (start, finish, plus redirector)
 2952:                 if($direction == FORWARD && $curRes->src()) { 
 2953:                     $resource = $curRes; $resourceCount++; 
 2954:                 }
 2955:                 my $resultingVal = $curRes->{DATA}->{$valName};
 2956:                 my $nextResources = $curRes->$nextResourceMethod();
 2957:                 my $nextCount = scalar(@{$nextResources});
 2958: 
 2959:                 if ($nextCount == 1) { # **3**
 2960:                     my $current = $nextResources->[0]->{DATA}->{$valName} || 999999999;
 2961:                     $nextResources->[0]->{DATA}->{$valName} = min($resultingVal, $current);
 2962:                 }
 2963:                 
 2964:                 if ($nextCount > 1) { # **4**
 2965:                     foreach my $res (@{$nextResources}) {
 2966:                         my $current = $res->{DATA}->{$valName} || 999999999;
 2967:                         $res->{DATA}->{$valName} = min($current, $resultingVal + 1);
 2968:                     }
 2969:                 }
 2970:             }
 2971:             
 2972:             # Assign the final val (**2**)
 2973:             if (ref($curRes) && $direction == BACKWARD()) {
 2974:                 my $finalDepth = min($curRes->{DATA}->{TOP_DOWN_VAL},
 2975:                                      $curRes->{DATA}->{BOT_UP_VAL});
 2976:                 
 2977:                 $curRes->{DATA}->{DISPLAY_DEPTH} = $finalDepth;
 2978:                 if ($finalDepth > $maxDepth) {$maxDepth = $finalDepth;}
 2979:             }
 2980: 
 2981: 	    $curRes = $iterator->next();
 2982:         }
 2983:     }
 2984: 
 2985:     # Check: Was this only one resource, a map?
 2986:     if ($resourceCount == 1 && $resource->is_sequence() && !$self->{FORCE_TOP}) { 
 2987:         my $firstResource = $resource->map_start();
 2988:         my $finishResource = $resource->map_finish();
 2989:         return 
 2990:             Apache::lonnavmaps::iterator->new($self->{NAV_MAP}, $firstResource,
 2991:                                               $finishResource, $self->{FILTER},
 2992:                                               $self->{ALREADY_SEEN}, 
 2993:                                               $self->{CONDITION},
 2994: 					      $self->{FORCE_TOP});
 2995:         
 2996:     }
 2997: 
 2998:     # Set up some bookkeeping information.
 2999:     $self->{CURRENT_DEPTH} = 0;
 3000:     $self->{MAX_DEPTH} = $maxDepth;
 3001:     $self->{STACK} = [];
 3002:     $self->{RECURSIVE_ITERATOR_FLAG} = 0;
 3003:     $self->{FINISHED} = 0; # When true, the iterator has finished
 3004: 
 3005:     for (my $i = 0; $i <= $self->{MAX_DEPTH}; $i++) {
 3006:         push @{$self->{STACK}}, [];
 3007:     }
 3008: 
 3009:     # Prime the recursion w/ the first resource **5**
 3010:     push @{$self->{STACK}->[0]}, $self->{FIRST_RESOURCE};
 3011:     $self->{ALREADY_SEEN}->{$self->{FIRST_RESOURCE}->{ID}} = 1;
 3012: 
 3013:     bless ($self);
 3014: 
 3015:     return $self;
 3016: }
 3017: 
 3018: sub next {
 3019:     my $self = shift;
 3020:     my $closeAllPages=shift;
 3021:     if ($self->{FINISHED}) {
 3022: 	return END_ITERATOR();
 3023:     }
 3024: 
 3025:     # If we want to return the top-level map object, and haven't yet,
 3026:     # do so.
 3027:     if ($self->{RETURN_0} && !$self->{HAVE_RETURNED_0}) {
 3028:         $self->{HAVE_RETURNED_0} = 1;
 3029:         return $self->{NAV_MAP}->getById('0.0');
 3030:     }
 3031:     if ($self->{RETURN_0} && !$self->{HAVE_RETURNED_0_BEGIN_MAP}) {
 3032: 	$self->{HAVE_RETURNED_0_BEGIN_MAP} = 1;
 3033: 	return $self->BEGIN_MAP();
 3034:     }
 3035: 
 3036:     if ($self->{RECURSIVE_ITERATOR_FLAG}) {
 3037:         # grab the next from the recursive iterator 
 3038:         my $next = $self->{RECURSIVE_ITERATOR}->next($closeAllPages);
 3039: 
 3040:         # is it a begin or end map? If so, update the depth
 3041:         if ($next == BEGIN_MAP() ) { $self->{RECURSIVE_DEPTH}++; }
 3042:         if ($next == END_MAP() ) { $self->{RECURSIVE_DEPTH}--; }
 3043: 
 3044:         # Are we back at depth 0? If so, stop recursing
 3045:         if ($self->{RECURSIVE_DEPTH} == 0) {
 3046:             $self->{RECURSIVE_ITERATOR_FLAG} = 0;
 3047:         }
 3048: 
 3049:         return $next;
 3050:     }
 3051: 
 3052:     if (defined($self->{FORCE_NEXT})) {
 3053:         my $tmp = $self->{FORCE_NEXT};
 3054:         $self->{FORCE_NEXT} = undef;
 3055:         return $tmp;
 3056:     }
 3057: 
 3058:     # Have we not yet begun? If not, return BEGIN_MAP and
 3059:     # remember we've started.
 3060:     if ( !$self->{STARTED} ) { 
 3061:         $self->{STARTED} = 1;
 3062:         return $self->BEGIN_MAP();
 3063:     }
 3064: 
 3065:     # Here's the guts of the iterator.
 3066:     
 3067:     # Find the next resource, if any.
 3068:     my $found = 0;
 3069:     my $i = $self->{MAX_DEPTH};
 3070:     my $newDepth;
 3071:     my $here;
 3072:     while ( $i >= 0 && !$found ) {
 3073:         if ( scalar(@{$self->{STACK}->[$i]}) > 0 ) { # **6**
 3074:             $here = pop @{$self->{STACK}->[$i]}; # **7**
 3075:             $found = 1;
 3076:             $newDepth = $i;
 3077:         }
 3078:         $i--;
 3079:     }
 3080: 
 3081:     # If we still didn't find anything, we're done.
 3082:     if ( !$found ) {
 3083:         # We need to get back down to the correct branch depth
 3084:         if ( $self->{CURRENT_DEPTH} > 0 ) {
 3085:             $self->{CURRENT_DEPTH}--;
 3086:             return END_BRANCH();
 3087:         } else {
 3088: 	    $self->{FINISHED} = 1;
 3089:             return END_MAP();
 3090:         }
 3091:     }
 3092: 
 3093:     # If this is not a resource, it must be an END_BRANCH marker we want
 3094:     # to return directly.
 3095:     if (!ref($here)) { # **8**
 3096:         if ($here == END_BRANCH()) { # paranoia, in case of later extension
 3097:             $self->{CURRENT_DEPTH}--;
 3098:             return $here;
 3099:         }
 3100:     }
 3101: 
 3102:     # Otherwise, it is a resource and it's safe to store in $self->{HERE}
 3103:     $self->{HERE} = $here;
 3104: 
 3105:     # Get to the right level
 3106:     if ( $self->{CURRENT_DEPTH} > $newDepth ) {
 3107:         push @{$self->{STACK}->[$newDepth]}, $here;
 3108:         $self->{CURRENT_DEPTH}--;
 3109:         return END_BRANCH();
 3110:     }
 3111:     if ( $self->{CURRENT_DEPTH} < $newDepth) {
 3112:         push @{$self->{STACK}->[$newDepth]}, $here;
 3113:         $self->{CURRENT_DEPTH}++;
 3114:         return BEGIN_BRANCH();
 3115:     }
 3116: 
 3117:     # If we made it here, we have the next resource, and we're at the
 3118:     # right branch level. So let's examine the resource for where
 3119:     # we can get to from here.
 3120: 
 3121:     # So we need to look at all the resources we can get to from here,
 3122:     # categorize them if we haven't seen them, remember if we have a new
 3123:     my $nextUnfiltered = $here->getNext();
 3124:     my $maxDepthAdded = -1;
 3125:     
 3126:     for (@$nextUnfiltered) {
 3127:         if (!defined($self->{ALREADY_SEEN}->{$_->{ID}})) {
 3128:             my $depth = $_->{DATA}->{DISPLAY_DEPTH};
 3129:             push @{$self->{STACK}->[$depth]}, $_;
 3130:             $self->{ALREADY_SEEN}->{$_->{ID}} = 1;
 3131:             if ($maxDepthAdded < $depth) { $maxDepthAdded = $depth; }
 3132:         }
 3133:     }
 3134: 
 3135:     # Is this the end of a branch? If so, all of the resources examined above
 3136:     # led to lower levels than the one we are currently at, so we push a END_BRANCH
 3137:     # marker onto the stack so we don't forget.
 3138:     # Example: For the usual A(BC)(DE)F case, when the iterator goes down the
 3139:     # BC branch and gets to C, it will see F as the only next resource, but it's
 3140:     # one level lower. Thus, this is the end of the branch, since there are no
 3141:     # more resources added to this level or above.
 3142:     # We don't do this if the examined resource is the finish resource,
 3143:     # because the condition given above is true, but the "END_MAP" will
 3144:     # take care of things and we should already be at depth 0.
 3145:     my $isEndOfBranch = $maxDepthAdded < $self->{CURRENT_DEPTH};
 3146:     if ($isEndOfBranch && $here != $self->{FINISH_RESOURCE}) { # **9**
 3147:         push @{$self->{STACK}->[$self->{CURRENT_DEPTH}]}, END_BRANCH();
 3148:     }
 3149: 
 3150:     # That ends the main iterator logic. Now, do we want to recurse
 3151:     # down this map (if this resource is a map)?
 3152:     if ( ($self->{HERE}->is_sequence() || (!$closeAllPages && $self->{HERE}->is_page())) &&
 3153:         (defined($self->{FILTER}->{$self->{HERE}->map_pc()}) xor $self->{CONDITION})) {
 3154:         $self->{RECURSIVE_ITERATOR_FLAG} = 1;
 3155:         my $firstResource = $self->{HERE}->map_start();
 3156:         my $finishResource = $self->{HERE}->map_finish();
 3157: 
 3158:         $self->{RECURSIVE_ITERATOR} = 
 3159:             Apache::lonnavmaps::iterator->new($self->{NAV_MAP}, $firstResource,
 3160:                                               $finishResource, $self->{FILTER},
 3161:                                               $self->{ALREADY_SEEN},
 3162: 					      $self->{CONDITION},
 3163: 					      $self->{FORCE_TOP});
 3164:     }
 3165: 
 3166:     # If this is a blank resource, don't actually return it.
 3167:     # Should you ever find you need it, make sure to add an option to the code
 3168:     #  that you can use; other things depend on this behavior.
 3169:     my $browsePriv = $self->{HERE}->browsePriv();
 3170:     if (!$self->{HERE}->src() || 
 3171:         (!($browsePriv eq 'F') && !($browsePriv eq '2')) ) {
 3172:         return $self->next($closeAllPages);
 3173:     }
 3174: 
 3175:     return $self->{HERE};
 3176: 
 3177: }
 3178: 
 3179: =pod
 3180: 
 3181: The other method available on the iterator is B<getStack>, which
 3182: returns an array populated with the current 'stack' of maps, as
 3183: references to the resource objects. Example: This is useful when
 3184: making the navigation map, as we need to check whether we are under a
 3185: page map to see if we need to link directly to the resource, or to the
 3186: page. The first elements in the array will correspond to the top of
 3187: the stack (most inclusive map).
 3188: 
 3189: =cut
 3190: 
 3191: sub getStack {
 3192:     my $self=shift;
 3193: 
 3194:     my @stack;
 3195: 
 3196:     $self->populateStack(\@stack);
 3197: 
 3198:     return \@stack;
 3199: }
 3200: 
 3201: # Private method: Calls the iterators recursively to populate the stack.
 3202: sub populateStack {
 3203:     my $self=shift;
 3204:     my $stack = shift;
 3205: 
 3206:     push @$stack, $self->{HERE} if ($self->{HERE});
 3207: 
 3208:     if ($self->{RECURSIVE_ITERATOR_FLAG}) {
 3209:         $self->{RECURSIVE_ITERATOR}->populateStack($stack);
 3210:     }
 3211: }
 3212: 
 3213: 1;
 3214: 
 3215: package Apache::lonnavmaps::DFSiterator;
 3216: use Scalar::Util qw(weaken);
 3217: use Apache::lonnet;
 3218: 
 3219: # Not documented in the perldoc: This is a simple iterator that just walks
 3220: #  through the nav map and presents the resources in a depth-first search
 3221: #  fashion, ignorant of conditionals, randomized resources, etc. It presents
 3222: #  BEGIN_MAP and END_MAP, but does not understand branches at all. It is
 3223: #  useful for pre-processing of some kind, and is in fact used by the main
 3224: #  iterator that way, but that's about it.
 3225: # One could imagine merging this into the init routine of the main iterator,
 3226: #  but this might as well be left separate, since it is possible some other
 3227: #  use might be found for it. - Jeremy
 3228: 
 3229: # Unlike the main iterator, this DOES return all resources, even blank ones.
 3230: #  The main iterator needs them to correctly preprocess the map.
 3231: 
 3232: sub BEGIN_MAP { return 1; }    # begining of a new map
 3233: sub END_MAP { return 2; }      # end of the map
 3234: sub FORWARD { return 1; }      # go forward
 3235: sub BACKWARD { return 2; }
 3236: 
 3237: # Params: Nav map ref, first resource id/ref, finish resource id/ref,
 3238: #         filter hash ref (or undef), already seen hash or undef, condition
 3239: #         (as in main iterator), direction FORWARD or BACKWARD (undef->forward).
 3240: sub new {
 3241:     # magic invocation to create a class instance
 3242:     my $proto = shift;
 3243:     my $class = ref($proto) || $proto;
 3244:     my $self = {};
 3245: 
 3246:     weaken($self->{NAV_MAP} = shift);
 3247:     return undef unless ($self->{NAV_MAP});
 3248: 
 3249:     $self->{FIRST_RESOURCE} = shift || $self->{NAV_MAP}->firstResource();
 3250:     $self->{FINISH_RESOURCE} = shift || $self->{NAV_MAP}->finishResource();
 3251: 
 3252:     # If the given resources are just the ID of the resource, get the
 3253:     # objects
 3254:     if (!ref($self->{FIRST_RESOURCE})) { $self->{FIRST_RESOURCE} = 
 3255:              $self->{NAV_MAP}->getById($self->{FIRST_RESOURCE}); }
 3256:     if (!ref($self->{FINISH_RESOURCE})) { $self->{FINISH_RESOURCE} = 
 3257:              $self->{NAV_MAP}->getById($self->{FINISH_RESOURCE}); }
 3258: 
 3259:     $self->{FILTER} = shift;
 3260: 
 3261:     # A hash, used as a set, of resource already seen
 3262:     $self->{ALREADY_SEEN} = shift;
 3263:      if (!defined($self->{ALREADY_SEEN})) { $self->{ALREADY_SEEN} = {} };
 3264:     $self->{CONDITION} = shift;
 3265:     $self->{DIRECTION} = shift || FORWARD();
 3266: 
 3267:     # Flag: Have we started yet?
 3268:     $self->{STARTED} = 0;
 3269: 
 3270:     # Should we continue calling the recursive iterator, if any?
 3271:     $self->{RECURSIVE_ITERATOR_FLAG} = 0;
 3272:     # The recursive iterator, if any
 3273:     $self->{RECURSIVE_ITERATOR} = undef;
 3274:     # Are we recursing on a map, or a branch?
 3275:     $self->{RECURSIVE_MAP} = 1; # we'll manually unset this when recursing on branches
 3276:     # And the count of how deep it is, so that this iterator can keep track of
 3277:     # when to pick back up again.
 3278:     $self->{RECURSIVE_DEPTH} = 0;
 3279: 
 3280:     # For keeping track of our branches, we maintain our own stack
 3281:     $self->{STACK} = [];
 3282: 
 3283:     # Start with the first resource
 3284:     if ($self->{DIRECTION} == FORWARD) {
 3285:         push @{$self->{STACK}}, $self->{FIRST_RESOURCE};
 3286:     } else {
 3287:         push @{$self->{STACK}}, $self->{FINISH_RESOURCE};
 3288:     }
 3289: 
 3290:     bless($self);
 3291:     return $self;
 3292: }
 3293: 
 3294: sub next {
 3295:     my $self = shift;
 3296:     
 3297:     # Are we using a recursive iterator? If so, pull from that and
 3298:     # watch the depth; we want to resume our level at the correct time.
 3299:     if ($self->{RECURSIVE_ITERATOR_FLAG}) {
 3300:         # grab the next from the recursive iterator
 3301:         my $next = $self->{RECURSIVE_ITERATOR}->next();
 3302:         
 3303:         # is it a begin or end map? Update depth if so
 3304:         if ($next == BEGIN_MAP() ) { $self->{RECURSIVE_DEPTH}++; }
 3305:         if ($next == END_MAP() ) { $self->{RECURSIVE_DEPTH}--; }
 3306: 
 3307:         # Are we back at depth 0? If so, stop recursing.
 3308:         if ($self->{RECURSIVE_DEPTH} == 0) {
 3309:             $self->{RECURSIVE_ITERATOR_FLAG} = 0;
 3310:         }
 3311:         
 3312:         return $next;
 3313:     }
 3314: 
 3315:     # Is there a current resource to grab? If not, then return
 3316:     # END_MAP, which will end the iterator.
 3317:     if (scalar(@{$self->{STACK}}) == 0) {
 3318:         return $self->END_MAP();
 3319:     }
 3320: 
 3321:     # Have we not yet begun? If not, return BEGIN_MAP and 
 3322:     # remember that we've started.
 3323:     if ( !$self->{STARTED} ) {
 3324:         $self->{STARTED} = 1;
 3325:         return $self->BEGIN_MAP;
 3326:     }
 3327: 
 3328:     # Get the next resource in the branch
 3329:     $self->{HERE} = pop @{$self->{STACK}};
 3330: 
 3331:     # remember that we've seen this, so we don't return it again later
 3332:     $self->{ALREADY_SEEN}->{$self->{HERE}->{ID}} = 1;
 3333:     
 3334:     # Get the next possible resources
 3335:     my $nextUnfiltered;
 3336:     if ($self->{DIRECTION} == FORWARD()) {
 3337:         $nextUnfiltered = $self->{HERE}->getNext();
 3338:     } else {
 3339:         $nextUnfiltered = $self->{HERE}->getPrevious();
 3340:     }
 3341:     my $next = [];
 3342: 
 3343:     # filter the next possibilities to remove things we've 
 3344:     # already seen.
 3345:     foreach my $item (@$nextUnfiltered) {
 3346:         if (!defined($self->{ALREADY_SEEN}->{$item->{ID}})) {
 3347:             push @$next, $item;
 3348:         }
 3349:     }
 3350: 
 3351:     while (@$next) {
 3352:         # copy the next possibilities over to the stack
 3353:         push @{$self->{STACK}}, shift @$next;
 3354:     }
 3355: 
 3356:     # If this is a map and we want to recurse down it... (not filtered out)
 3357:     if ($self->{HERE}->is_map() && 
 3358:          (defined($self->{FILTER}->{$self->{HERE}->map_pc()}) xor $self->{CONDITION})) { 
 3359:         $self->{RECURSIVE_ITERATOR_FLAG} = 1;
 3360:         my $firstResource = $self->{HERE}->map_start();
 3361:         my $finishResource = $self->{HERE}->map_finish();
 3362: 
 3363:         $self->{RECURSIVE_ITERATOR} =
 3364:           Apache::lonnavmaps::DFSiterator->new ($self->{NAV_MAP}, $firstResource, 
 3365:                      $finishResource, $self->{FILTER}, $self->{ALREADY_SEEN},
 3366:                                              $self->{CONDITION}, $self->{DIRECTION});
 3367:     }
 3368: 
 3369:     return $self->{HERE};
 3370: }
 3371: 
 3372: # Identical to the full iterator methods of the same name. Hate to copy/paste
 3373: # but I also hate to "inherit" either iterator from the other.
 3374: 
 3375: sub getStack {
 3376:     my $self=shift;
 3377: 
 3378:     my @stack;
 3379: 
 3380:     $self->populateStack(\@stack);
 3381: 
 3382:     return \@stack;
 3383: }
 3384: 
 3385: # Private method: Calls the iterators recursively to populate the stack.
 3386: sub populateStack {
 3387:     my $self=shift;
 3388:     my $stack = shift;
 3389: 
 3390:     push @$stack, $self->{HERE} if ($self->{HERE});
 3391: 
 3392:     if ($self->{RECURSIVE_ITERATOR_FLAG}) {
 3393:         $self->{RECURSIVE_ITERATOR}->populateStack($stack);
 3394:     }
 3395: }
 3396: 
 3397: 1;
 3398: 
 3399: package Apache::lonnavmaps::resource;
 3400: use Scalar::Util qw(weaken);
 3401: use Apache::lonnet;
 3402: 
 3403: =pod
 3404: 
 3405: =head1 Object: resource 
 3406: 
 3407: X<resource, navmap object>
 3408: A resource object encapsulates a resource in a resource map, allowing
 3409: easy manipulation of the resource, querying the properties of the
 3410: resource (including user properties), and represents a reference that
 3411: can be used as the canonical representation of the resource by
 3412: lonnavmap clients like renderers.
 3413: 
 3414: A resource only makes sense in the context of a navmap, as some of the
 3415: data is stored in the navmap object.
 3416: 
 3417: You will probably never need to instantiate this object directly. Use
 3418: Apache::lonnavmaps::navmap, and use the "start" method to obtain the
 3419: starting resource.
 3420: 
 3421: Resource objects respect the parameter_hiddenparts, which suppresses 
 3422: various parts according to the wishes of the map author. As of this
 3423: writing, there is no way to override this parameter, and suppressed
 3424: parts will never be returned, nor will their response types or ids be
 3425: stored.
 3426: 
 3427: =head2 Overview
 3428: 
 3429: A B<Resource> is the most granular type of object in LON-CAPA that can
 3430: be included in a course. It can either be a particular resource, like
 3431: an HTML page, external resource, problem, etc., or it can be a
 3432: container sequence, such as a "page" or a "map".
 3433: 
 3434: To see a sequence from the user's point of view, please see the
 3435: B<Creating a Course: Maps and Sequences> chapter of the Author's
 3436: Manual.
 3437: 
 3438: A Resource Object, once obtained from a navmap object via a B<getBy*>
 3439: method of the navmap, or from an iterator, allows you to query
 3440: information about that resource.
 3441: 
 3442: Generally, you do not ever want to create a resource object yourself,
 3443: so creation has been left undocumented. Always retrieve resources
 3444: from navmap objects.
 3445: 
 3446: =head3 Identifying Resources
 3447: 
 3448: X<big hash>Every resource is identified by a Resource ID in the big hash that is
 3449: unique to that resource for a given course. X<resource ID, in big hash>
 3450: The Resource ID has the form #.#, where the first number is the same
 3451: for every resource in a map, and the second is unique. For instance,
 3452: for a course laid out like this:
 3453: 
 3454:  * Problem 1
 3455:  * Map
 3456:    * Resource 2
 3457:    * Resource 3
 3458: 
 3459: C<Problem 1> and C<Map> will share a first number, and C<Resource 2>
 3460: C<Resource 3> will share a first number. The second number may end up
 3461: re-used between the two groups.
 3462: 
 3463: The resource ID is only used in the big hash, but can be used in the
 3464: context of a course to identify a resource easily. (For instance, the
 3465: printing system uses it to record which resources from a sequence you 
 3466: wish to print.)
 3467: 
 3468: X<symb> X<resource, symb>
 3469: All resources also have B<symb>s, which uniquely identify a resource
 3470: in a course. Many internal LON-CAPA functions expect a symb. A symb
 3471: carries along with it the URL of the resource, and the map it appears
 3472: in. Symbs are much larger than resource IDs.
 3473: 
 3474: =cut
 3475: 
 3476: sub new {
 3477:     # magic invocation to create a class instance
 3478:     my $proto = shift;
 3479:     my $class = ref($proto) || $proto;
 3480:     my $self = {};
 3481: 
 3482:     weaken($self->{NAV_MAP} = shift);
 3483:     $self->{ID} = shift;
 3484: 
 3485:     # Store this new resource in the parent nav map's cache.
 3486:     $self->{NAV_MAP}->{RESOURCE_CACHE}->{$self->{ID}} = $self;
 3487:     $self->{RESOURCE_ERROR} = 0;
 3488: 
 3489:     # A hash that can be used by two-pass algorithms to store data
 3490:     # about this resource in. Not used by the resource object
 3491:     # directly.
 3492:     $self->{DATA} = {};
 3493:    
 3494:     bless($self);
 3495:     
 3496:     return $self;
 3497: }
 3498: 
 3499: # private function: simplify the NAV_HASH lookups we keep doing
 3500: # pass the name, and to automatically append my ID, pass a true val on the
 3501: # second param
 3502: sub navHash {
 3503:     my $self = shift;
 3504:     my $param = shift;
 3505:     my $id = shift;
 3506:     return $self->{NAV_MAP}->navhash($param . ($id?$self->{ID}:""));
 3507: }
 3508: 
 3509: =pod
 3510: 
 3511: =head2 Methods
 3512: 
 3513: Once you have a resource object, here's what you can do with it:
 3514: 
 3515: =head3 Attribute Retrieval
 3516: 
 3517: Every resource has certain attributes that can be retrieved and used:
 3518: 
 3519: =over 4
 3520: 
 3521: =item * B<ID>: Every resource has an ID that is unique for that
 3522:     resource in the course it is in. The ID is actually in the hash
 3523:     representing the resource, so for a resource object $res, obtain
 3524:     it via C<$res->{ID}).
 3525: 
 3526: =item * B<compTitle>:
 3527: 
 3528: Returns a "composite title", that is equal to $res->title() if the
 3529: resource has a title, and is otherwise the last part of the URL (e.g.,
 3530: "problem.problem").
 3531: 
 3532: =item * B<ext>:
 3533: 
 3534: Returns true if the resource is external.
 3535: 
 3536: =item * B<kind>:
 3537: 
 3538: Returns the kind of the resource from the compiled nav map.
 3539: 
 3540: =item * B<randomout>:
 3541: 
 3542: Returns true if this resource was chosen to NOT be shown to the user
 3543: by the random map selection feature. In other words, this is usually
 3544: false.
 3545: 
 3546: =item * B<randompick>:
 3547: 
 3548: Returns the number of randomly picked items for a map if the randompick
 3549: feature is being used on the map. 
 3550: 
 3551: =item * B<randomorder>:
 3552: 
 3553: Returns true for a map if the randomorder feature is being used on the
 3554: map.
 3555: 
 3556: =item * B<src>:
 3557: 
 3558: Returns the source for the resource.
 3559: 
 3560: =item * B<symb>:
 3561: 
 3562: Returns the symb for the resource.
 3563: 
 3564: =item * B<title>:
 3565: 
 3566: Returns the title of the resource.
 3567: 
 3568: =back
 3569: 
 3570: =cut
 3571: 
 3572: # These info functions can be used directly, as they don't return
 3573: # resource information.
 3574: sub comesfrom { my $self=shift; return $self->navHash("comesfrom_", 1); }
 3575: sub encrypted { my $self=shift; return $self->navHash("encrypted_", 1); }
 3576: sub ext { my $self=shift; return $self->navHash("ext_", 1) eq 'true:'; }
 3577: sub from { my $self=shift; return $self->navHash("from_", 1); }
 3578: # considered private and undocumented
 3579: sub goesto { my $self=shift; return $self->navHash("goesto_", 1); }
 3580: sub kind { my $self=shift; return $self->navHash("kind_", 1); }
 3581: sub randomout { my $self=shift; return $self->navHash("randomout_", 1); }
 3582: sub randompick { 
 3583:     my $self = shift;
 3584:     my $randompick = $self->parmval('randompick');
 3585:     return $randompick;
 3586: }
 3587: sub randomorder { 
 3588:     my $self = shift;
 3589:     my $randomorder = $self->parmval('randomorder');
 3590:     return ($randomorder =~ /^yes$/i);
 3591: }
 3592: sub link {
 3593:     my $self=shift;
 3594:     if ($self->encrypted()) { return &Apache::lonenc::encrypted($self->src); }
 3595:     return $self->src;
 3596: }
 3597: sub src { 
 3598:     my $self=shift;
 3599:     return $self->navHash("src_", 1);
 3600: }
 3601: sub shown_symb {
 3602:     my $self=shift;
 3603:     if ($self->encrypted()) {return &Apache::lonenc::encrypted($self->symb());}
 3604:     return $self->symb();
 3605: }
 3606: sub id {
 3607:     my $self=shift;
 3608:     return $self->{ID};
 3609: }
 3610: sub enclosing_map_src {
 3611:     my $self=shift;
 3612:     (my $first, my $second) = $self->{ID} =~ /(\d+).(\d+)/;
 3613:     return $self->navHash('map_id_'.$first);
 3614: }
 3615: sub symb {
 3616:     my $self=shift;
 3617:     (my $first, my $second) = $self->{ID} =~ /(\d+).(\d+)/;
 3618:     my $symbSrc = &Apache::lonnet::declutter($self->src());
 3619:     my $symb = &Apache::lonnet::declutter($self->navHash('map_id_'.$first)) 
 3620:         . '___' . $second . '___' . $symbSrc;
 3621:     return &Apache::lonnet::symbclean($symb);
 3622: }
 3623: sub wrap_symb {
 3624:     my $self = shift;
 3625:     return $self->{NAV_MAP}->wrap_symb($self->symb());
 3626: }
 3627: sub title { 
 3628:     my $self=shift; 
 3629:     if ($self->{ID} eq '0.0') {
 3630: 	# If this is the top-level map, return the title of the course
 3631: 	# since this map can not be titled otherwise.
 3632: 	return $env{'course.'.$env{'request.course.id'}.'.description'};
 3633:     }
 3634:     return $self->navHash("title_", 1); }
 3635: # considered private and undocumented
 3636: sub to { my $self=shift; return $self->navHash("to_", 1); }
 3637: sub condition {
 3638:     my $self=shift;
 3639:     my $undercond=$self->navHash("undercond_", 1);
 3640:     if (!defined($undercond)) { return 1; };
 3641:     my $condid=$self->navHash("condid_$undercond");
 3642:     if (!defined($condid)) { return 1; };
 3643:     my $condition=&Apache::lonnet::directcondval($condid);
 3644:     return $condition;
 3645: }
 3646: sub condval {
 3647:     my $self=shift;
 3648:     my ($pathname,$filename) = 
 3649: 	&Apache::lonnet::split_uri_for_cond($self->src());
 3650: 
 3651:     my $match=($env{'acc.res.'.$env{'request.course.id'}.'.'.$pathname}=~
 3652: 	       /\&\Q$filename\E\:([\d\|]+)\&/);
 3653:     if ($match) {
 3654: 	return &Apache::lonnet::condval($1);
 3655:     }
 3656:     return 0;
 3657: }
 3658: sub compTitle {
 3659:     my $self = shift;
 3660:     my $title = $self->title();
 3661:     $title=~s/\&colon\;/\:/gs;
 3662:     if (!$title) {
 3663:         $title = $self->src();
 3664:         $title = substr($title, rindex($title, '/') + 1);
 3665:     }
 3666:     return $title;
 3667: }
 3668: 
 3669: =pod
 3670: 
 3671: B<Predicate Testing the Resource>
 3672: 
 3673: These methods are shortcuts to deciding if a given resource has a given property.
 3674: 
 3675: =over 4
 3676: 
 3677: =item * B<is_map>:
 3678: 
 3679: Returns true if the resource is a map type.
 3680: 
 3681: =item * B<is_problem>:
 3682: 
 3683: Returns true if the resource is a problem type, false
 3684: otherwise. (Looks at the extension on the src field; might need more
 3685: to work correctly.)
 3686: 
 3687: =item * B<is_page>:
 3688: 
 3689: Returns true if the resource is a page.
 3690: 
 3691: =item * B<is_sequence>:
 3692: 
 3693: Returns true if the resource is a sequence.
 3694: 
 3695: =back
 3696: 
 3697: =cut
 3698: 
 3699: sub hasResource {
 3700:    my $self = shift;
 3701:    return $self->{NAV_MAP}->hasResource(@_);
 3702: }
 3703: 
 3704: sub retrieveResources {
 3705:    my $self = shift;
 3706:    return $self->{NAV_MAP}->retrieveResources(@_);
 3707: }
 3708: 
 3709: sub is_exam {
 3710:     my ($self,$part) = @_;
 3711:     my $type = $self->parmval('type',$part);
 3712:     if ($type eq 'exam') {
 3713:         return 1;
 3714:     }
 3715:     if ($self->src() =~ /\.(exam)$/) {
 3716:         return 1;
 3717:     }
 3718:     return 0;
 3719: }
 3720: sub is_html {
 3721:     my $self=shift;
 3722:     my $src = $self->src();
 3723:     return ($src =~ /html$/);
 3724: }
 3725: sub is_map { my $self=shift; return defined($self->navHash("is_map_", 1)); }
 3726: sub is_page {
 3727:     my $self=shift;
 3728:     my $src = $self->src();
 3729:     return $self->navHash("is_map_", 1) && 
 3730: 	$self->navHash("map_type_" . $self->map_pc()) eq 'page';
 3731: }
 3732: sub is_practice {
 3733:     my $self=shift;
 3734:     my ($part) = @_;
 3735:     my $type = $self->parmval('type',$part);
 3736:     if ($type eq 'practice') {
 3737:         return 1;
 3738:     }
 3739:     return 0;
 3740: }
 3741: sub is_problem {
 3742:     my $self=shift;
 3743:     my $src = $self->src();
 3744:     if ($src =~ /\.(problem|exam|quiz|assess|survey|form|library|task)$/) {
 3745: 	return !($self->is_practice());
 3746:     }
 3747:     return 0;
 3748: }
 3749: sub is_raw_problem {
 3750:     my $self=shift;
 3751:     my $src = $self->src();
 3752:     if ($src =~ /\.(problem|exam|quiz|assess|survey|form|library|task)$/) {
 3753:         return 1;
 3754:     }
 3755:     return 0;
 3756: }
 3757: 
 3758: sub contains_problem {
 3759:     my $self=shift;
 3760:     if ($self->is_page()) {
 3761: 	my $hasProblem=$self->hasResource($self,sub { $_[0]->is_problem() },1);
 3762: 	return $hasProblem;
 3763:     }
 3764:     return 0;
 3765: }
 3766: sub map_contains_problem {
 3767:     my $self=shift;
 3768:     if ($self->is_map()) {
 3769: 	my $has_problem=
 3770: 	    $self->hasResource($self,sub { $_[0]->is_problem() },1);
 3771: 	return $has_problem;
 3772:     }
 3773:     return 0;
 3774: }
 3775: sub is_sequence {
 3776:     my $self=shift;
 3777:     return $self->navHash("is_map_", 1) && 
 3778:     $self->navHash("map_type_" . $self->map_pc()) eq 'sequence';
 3779: }
 3780: sub is_survey {
 3781:     my $self = shift();
 3782:     my $part = shift();
 3783:     my $type = $self->parmval('type',$part);
 3784:     if ($type eq 'survey') {
 3785:         return 1;
 3786:     }
 3787:     if ($self->src() =~ /\.(survey)$/) {
 3788:         return 1;
 3789:     }
 3790:     return 0;
 3791: }
 3792: sub is_task {
 3793:     my $self=shift;
 3794:     my $src = $self->src();
 3795:     return ($src =~ /\.(task)$/)
 3796: }
 3797: 
 3798: sub is_empty_sequence {
 3799:     my $self=shift;
 3800:     my $src = $self->src();
 3801:     return !$self->is_page() && $self->navHash("is_map_", 1) && !$self->navHash("map_type_" . $self->map_pc());
 3802: }
 3803: 
 3804: # Private method: Shells out to the parmval in the nav map, handler parts.
 3805: sub parmval {
 3806:     my $self = shift;
 3807:     my $what = shift;
 3808:     my $part = shift;
 3809:     if (!defined($part)) { 
 3810:         $part = '0'; 
 3811:     }
 3812:     return $self->{NAV_MAP}->parmval($part.'.'.$what, $self->symb());
 3813: }
 3814: 
 3815: =pod
 3816: 
 3817: B<Map Methods>
 3818: 
 3819: These methods are useful for getting information about the map
 3820: properties of the resource, if the resource is a map (B<is_map>).
 3821: 
 3822: =over 4
 3823: 
 3824: =item * B<map_finish>:
 3825: 
 3826: Returns a reference to a resource object corresponding to the finish
 3827: resource of the map.
 3828: 
 3829: =item * B<map_pc>:
 3830: 
 3831: Returns the pc value of the map, which is the first number that
 3832: appears in the resource ID of the resources in the map, and is the
 3833: number that appears around the middle of the symbs of the resources in
 3834: that map.
 3835: 
 3836: =item * B<map_start>:
 3837: 
 3838: Returns a reference to a resource object corresponding to the start
 3839: resource of the map.
 3840: 
 3841: =item * B<map_type>:
 3842: 
 3843: Returns a string with the type of the map in it.
 3844: 
 3845: =back
 3846: 
 3847: =cut
 3848: 
 3849: sub map_finish {
 3850:     my $self = shift;
 3851:     my $src = $self->src();
 3852:     $src = &Apache::lonnet::clutter($src);
 3853:     my $res = $self->navHash("map_finish_$src", 0);
 3854:     $res = $self->{NAV_MAP}->getById($res);
 3855:     return $res;
 3856: }
 3857: sub map_pc {
 3858:     my $self = shift;
 3859:     my $src = $self->src();
 3860:     return $self->navHash("map_pc_$src", 0);
 3861: }
 3862: sub map_start {
 3863:     my $self = shift;
 3864:     my $src = $self->src();
 3865:     $src = &Apache::lonnet::clutter($src);
 3866:     my $res = $self->navHash("map_start_$src", 0);
 3867:     $res = $self->{NAV_MAP}->getById($res);
 3868:     return $res;
 3869: }
 3870: sub map_type {
 3871:     my $self = shift;
 3872:     my $pc = $self->map_pc();
 3873:     return $self->navHash("map_type_$pc", 0);
 3874: }
 3875: 
 3876: #####
 3877: # Property queries
 3878: #####
 3879: 
 3880: # These functions will be responsible for returning the CORRECT
 3881: # VALUE for the parameter, no matter what. So while they may look
 3882: # like direct calls to parmval, they can be more than that.
 3883: # So, for instance, the duedate function should use the "duedatetype"
 3884: # information, rather than the resource object user.
 3885: 
 3886: =pod
 3887: 
 3888: =head2 Resource Parameters
 3889: 
 3890: In order to use the resource parameters correctly, the nav map must
 3891: have been instantiated with genCourseAndUserOptions set to true, so
 3892: the courseopt and useropt is read correctly. Then, you can call these
 3893: functions to get the relevant parameters for the resource. Each
 3894: function defaults to part "0", but can be directed to another part by
 3895: passing the part as the parameter.
 3896: 
 3897: These methods are responsible for getting the parameter correct, not
 3898: merely reflecting the contents of the GDBM hashes. As we move towards
 3899: dates relative to other dates, these methods should be updated to
 3900: reflect that. (Then, anybody using these methods will not have to update
 3901: their code.)
 3902: 
 3903: =over 4
 3904: 
 3905: =item * B<acc>:
 3906: 
 3907: Get the Client IP/Name Access Control information.
 3908: 
 3909: =item * B<answerdate>:
 3910: 
 3911: Get the answer-reveal date for the problem.
 3912: 
 3913: =item * B<awarded>: 
 3914: 
 3915: Gets the awarded value for the problem part. Requires genUserData set to
 3916: true when the navmap object was created.
 3917: 
 3918: =item * B<duedate>:
 3919: 
 3920: Get the due date for the problem.
 3921: 
 3922: =item * B<tries>:
 3923: 
 3924: Get the number of tries the student has used on the problem.
 3925: 
 3926: =item * B<maxtries>:
 3927: 
 3928: Get the number of max tries allowed.
 3929: 
 3930: =item * B<opendate>:
 3931: 
 3932: Get the open date for the problem.
 3933: 
 3934: =item * B<sig>:
 3935: 
 3936: Get the significant figures setting.
 3937: 
 3938: =item * B<tol>:
 3939: 
 3940: Get the tolerance for the problem.
 3941: 
 3942: =item * B<tries>:
 3943: 
 3944: Get the number of tries the user has already used on the problem.
 3945: 
 3946: =item * B<type>:
 3947: 
 3948: Get the question type for the problem.
 3949: 
 3950: =item * B<weight>:
 3951: 
 3952: Get the weight for the problem.
 3953: 
 3954: =back
 3955: 
 3956: =cut
 3957: 
 3958: sub acc {
 3959:     (my $self, my $part) = @_;
 3960:     my $acc = $self->parmval("acc", $part);
 3961:     return $acc;
 3962: }
 3963: sub answerdate {
 3964:     (my $self, my $part) = @_;
 3965:     # Handle intervals
 3966:     my $answerdatetype = $self->parmval("answerdate.type", $part);
 3967:     my $answerdate = $self->parmval("answerdate", $part);
 3968:     my $duedate = $self->parmval("duedate", $part);
 3969:     if ($answerdatetype eq 'date_interval') {
 3970:         $answerdate = $duedate + $answerdate; 
 3971:     }
 3972:     return $answerdate;
 3973: }
 3974: sub awarded { 
 3975:     my $self = shift; my $part = shift;
 3976:     $self->{NAV_MAP}->get_user_data();
 3977:     if (!defined($part)) { $part = '0'; }
 3978:     return $self->{NAV_MAP}->{STUDENT_DATA}->{$self->symb()}->{'resource.'.$part.'.awarded'};
 3979: }
 3980: # this should work exactly like the copy in lonhomework.pm
 3981: sub duedate {
 3982:     (my $self, my $part) = @_;
 3983:     my $date;
 3984:     my @interval=$self->parmval("interval", $part);
 3985:     my $due_date=$self->parmval("duedate", $part);
 3986:     if ($interval[0] =~ /\d+/) {
 3987:        my $first_access=&Apache::lonnet::get_first_access($interval[1],
 3988:                                                           $self->symb);
 3989: 	if (defined($first_access)) {
 3990:            my $interval = $first_access+$interval[0];
 3991: 	    $date = (!$due_date || $interval < $due_date) ? $interval 
 3992:                                                           : $due_date;
 3993: 	} else {
 3994: 	    $date = $due_date;
 3995: 	}
 3996:     } else {
 3997: 	$date = $due_date;
 3998:     }
 3999:     return $date;
 4000: }
 4001: sub handgrade {
 4002:     (my $self, my $part) = @_;
 4003:     my @response_ids = $self->responseIds($part);
 4004:     if (@response_ids) {
 4005: 	foreach my $response_id (@response_ids) {
 4006:             my $handgrade = $self->parmval("handgrade",$part.'_'.$response_id);
 4007: 	    if (lc($handgrade) eq 'yes') {
 4008: 		return 'yes';
 4009: 	    }
 4010: 	}
 4011:     }
 4012:     my $handgrade = $self->parmval("handgrade", $part);
 4013:     return $handgrade;
 4014: }
 4015: sub maxtries {
 4016:     (my $self, my $part) = @_;
 4017:     my $maxtries = $self->parmval("maxtries", $part);
 4018:     return $maxtries;
 4019: }
 4020: sub opendate {
 4021:     (my $self, my $part) = @_;
 4022:     my $opendatetype = $self->parmval("opendate.type", $part);
 4023:     my $opendate = $self->parmval("opendate", $part); 
 4024:     if ($opendatetype eq 'date_interval') {
 4025:         my $duedate = $self->duedate($part);
 4026:         $opendate = $duedate - $opendate; 
 4027:     }
 4028:     return $opendate;
 4029: }
 4030: sub problemstatus {
 4031:     (my $self, my $part) = @_;
 4032:     my $problemstatus = $self->parmval("problemstatus", $part);
 4033:     return lc($problemstatus);
 4034: }
 4035: sub sig {
 4036:     (my $self, my $part) = @_;
 4037:     my $sig = $self->parmval("sig", $part);
 4038:     return $sig;
 4039: }
 4040: sub tol {
 4041:     (my $self, my $part) = @_;
 4042:     my $tol = $self->parmval("tol", $part);
 4043:     return $tol;
 4044: }
 4045: sub tries {
 4046:     my $self = shift; 
 4047:     my $tries = $self->queryRestoreHash('tries', shift);
 4048:     if (!defined($tries)) { return '0';}
 4049:     return $tries;
 4050: }
 4051: sub type {
 4052:     (my $self, my $part) = @_;
 4053:     my $type = $self->parmval("type", $part);
 4054:     return $type;
 4055: }
 4056: sub weight { 
 4057:     my $self = shift; my $part = shift;
 4058:     if (!defined($part)) { $part = '0'; }
 4059:     my $weight = &Apache::lonnet::EXT('resource.'.$part.'.weight',
 4060:                                 $self->symb(), $env{'user.domain'},
 4061:                                 $env{'user.name'},
 4062:                                 $env{'request.course.sec'});
 4063:     return $weight;
 4064: }
 4065: sub part_display {
 4066:     my $self= shift(); my $partID = shift();
 4067:     if (! defined($partID)) { $partID = '0'; }
 4068:     my $display=&Apache::lonnet::EXT('resource.'.$partID.'.display',
 4069:                                      $self->symb);
 4070:     if (! defined($display) || $display eq '') {
 4071:         $display = $partID;
 4072:     }
 4073:     return $display;
 4074: }
 4075: 
 4076: # Multiple things need this
 4077: sub getReturnHash {
 4078:     my $self = shift;
 4079:     
 4080:     if (!defined($self->{RETURN_HASH})) {
 4081:         my %tmpHash  = &Apache::lonnet::restore($self->symb());
 4082:         $self->{RETURN_HASH} = \%tmpHash;
 4083:     }
 4084: }       
 4085: 
 4086: ######
 4087: # Status queries
 4088: ######
 4089: 
 4090: # These methods query the status of problems.
 4091: 
 4092: # If we need to count parts, this function determines the number of
 4093: # parts from the metadata. When called, it returns a reference to a list
 4094: # of strings corresponding to the parts. (Thus, using it in a scalar context
 4095: # tells you how many parts you have in the problem:
 4096: # $partcount = scalar($resource->countParts());
 4097: # Don't use $self->{PARTS} directly because you don't know if it's been
 4098: # computed yet.
 4099: 
 4100: =pod
 4101: 
 4102: =head2 Resource misc
 4103: 
 4104: Misc. functions for the resource.
 4105: 
 4106: =over 4
 4107: 
 4108: =item * B<hasDiscussion>:
 4109: 
 4110: Returns a false value if there has been discussion since the user last
 4111: logged in, true if there has. Always returns false if the discussion
 4112: data was not extracted when the nav map was constructed.
 4113: 
 4114: =item * B<last_post_time>:
 4115: 
 4116: Returns a false value if there hasn't been discussion otherwise returns
 4117: unix timestamp of last time a discussion posting (or edit) was made.
 4118: 
 4119: =item * B<discussion_info>:
 4120: 
 4121: optional argument is a filter (currently can be 'unread');
 4122: returns in scalar context the count of the number of discussion postings.
 4123: 
 4124: returns in list context both the count of postings and a hash ref
 4125: containing information about the postings (subject, id, timestamp) in a hash.
 4126: 
 4127: Default is to return counts for all postings.  However if called with a second argument set to 'unread', will return information about only unread postings.
 4128: 
 4129: =item * B<getFeedback>:
 4130: 
 4131: Gets the feedback for the resource and returns the raw feedback string
 4132: for the resource, or the null string if there is no feedback or the
 4133: email data was not extracted when the nav map was constructed. Usually
 4134: used like this:
 4135: 
 4136:  for my $url (split(/\,/, $res->getFeedback())) {
 4137:     my $link = &escape($url);
 4138:     ...
 4139: 
 4140: and use the link as appropriate.
 4141: 
 4142: =cut
 4143: 
 4144: sub hasDiscussion {
 4145:     my $self = shift;
 4146:     return $self->{NAV_MAP}->hasDiscussion($self->symb());
 4147: }
 4148: 
 4149: sub last_post_time {
 4150:     my $self = shift;
 4151:     return $self->{NAV_MAP}->last_post_time($self->symb());
 4152: }
 4153: 
 4154: sub discussion_info {
 4155:     my ($self,$filter) = @_;
 4156:     return $self->{NAV_MAP}->discussion_info($self->symb(),$filter);
 4157: }
 4158: 
 4159: sub getFeedback {
 4160:     my $self = shift;
 4161:     my $source = $self->src();
 4162:     my $symb = $self->symb();
 4163:     if ($source =~ /^\/res\//) { $source = substr $source, 5; }
 4164:     return $self->{NAV_MAP}->getFeedback($symb,$source);
 4165: }
 4166: 
 4167: sub getErrors {
 4168:     my $self = shift;
 4169:     my $source = $self->src();
 4170:     my $symb = $self->symb();
 4171:     if ($source =~ /^\/res\//) { $source = substr $source, 5; }
 4172:     return $self->{NAV_MAP}->getErrors($symb,$source);
 4173: }
 4174: 
 4175: =pod
 4176: 
 4177: =item * B<parts>():
 4178: 
 4179: Returns a list reference containing sorted strings corresponding to
 4180: each part of the problem. Single part problems have only a part '0'.
 4181: Multipart problems do not return their part '0', since they typically
 4182: do not really matter. 
 4183: 
 4184: =item * B<countParts>():
 4185: 
 4186: Returns the number of parts of the problem a student can answer. Thus,
 4187: for single part problems, returns 1. For multipart, it returns the
 4188: number of parts in the problem, not including psuedo-part 0. 
 4189: 
 4190: =item * B<countResponses>():
 4191: 
 4192: Returns the total number of responses in the problem a student can answer.
 4193: 
 4194: =item * B<responseTypes>():
 4195: 
 4196: Returns a hash whose keys are the response types.  The values are the number 
 4197: of times each response type is used.  This is for the I<entire> problem, not 
 4198: just a single part.
 4199: 
 4200: =item * B<multipart>():
 4201: 
 4202: Returns true if the problem is multipart, false otherwise. Use this instead
 4203: of countParts if all you want is multipart/not multipart.
 4204: 
 4205: =item * B<responseType>($part):
 4206: 
 4207: Returns the response type of the part, without the word "response" on the
 4208: end. Example return values: 'string', 'essay', 'numeric', etc.
 4209: 
 4210: =item * B<responseIds>($part):
 4211: 
 4212: Retreives the response IDs for the given part as an array reference containing
 4213: strings naming the response IDs. This may be empty.
 4214: 
 4215: =back
 4216: 
 4217: =cut
 4218: 
 4219: sub parts {
 4220:     my $self = shift;
 4221: 
 4222:     if ($self->ext) { return []; }
 4223: 
 4224:     $self->extractParts();
 4225:     return $self->{PARTS};
 4226: }
 4227: 
 4228: sub countParts {
 4229:     my $self = shift;
 4230:     
 4231:     my $parts = $self->parts();
 4232: 
 4233:     # If I left this here, then it's not necessary.
 4234:     #my $delta = 0;
 4235:     #for my $part (@$parts) {
 4236:     #    if ($part eq '0') { $delta--; }
 4237:     #}
 4238: 
 4239:     if ($self->{RESOURCE_ERROR}) {
 4240:         return 0;
 4241:     }
 4242: 
 4243:     return scalar(@{$parts}); # + $delta;
 4244: }
 4245: 
 4246: sub countResponses {
 4247:     my $self = shift;
 4248:     my $count;
 4249:     foreach my $part (@{$self->parts()}) {
 4250:         $count+= scalar($self->responseIds($part));
 4251:     }
 4252:     return $count;
 4253: }
 4254: 
 4255: sub responseTypes {
 4256:     my $self = shift;
 4257:     my %responses;
 4258:     foreach my $part (@{$self->parts()}) {
 4259:         foreach my $responsetype ($self->responseType($part)) {
 4260:             $responses{$responsetype}++ if (defined($responsetype));
 4261:         }
 4262:     }
 4263:     return %responses;
 4264: }
 4265: 
 4266: sub multipart {
 4267:     my $self = shift;
 4268:     return $self->countParts() > 1;
 4269: }
 4270: 
 4271: sub singlepart {
 4272:     my $self = shift;
 4273:     return $self->countParts() == 1;
 4274: }
 4275: 
 4276: sub responseType {
 4277:     my $self = shift;
 4278:     my $part = shift;
 4279: 
 4280:     $self->extractParts();
 4281:     if (defined($self->{RESPONSE_TYPES}->{$part})) {
 4282: 	return @{$self->{RESPONSE_TYPES}->{$part}};
 4283:     } else {
 4284: 	return undef;
 4285:     }
 4286: }
 4287: 
 4288: sub responseIds {
 4289:     my $self = shift;
 4290:     my $part = shift;
 4291: 
 4292:     $self->extractParts();
 4293:     if (defined($self->{RESPONSE_IDS}->{$part})) {
 4294: 	return @{$self->{RESPONSE_IDS}->{$part}};
 4295:     } else {
 4296: 	return undef;
 4297:     }
 4298: }
 4299: 
 4300: # Private function: Extracts the parts information, both part names and
 4301: # part types, and saves it. 
 4302: sub extractParts { 
 4303:     my $self = shift;
 4304:     
 4305:     return if (defined($self->{PARTS}));
 4306:     return if ($self->ext);
 4307: 
 4308:     $self->{PARTS} = [];
 4309: 
 4310:     my %parts;
 4311: 
 4312:     # Retrieve part count, if this is a problem
 4313:     if ($self->is_problem()) {
 4314: 	my $partorder = &Apache::lonnet::metadata($self->src(), 'partorder');
 4315:         my $metadata = &Apache::lonnet::metadata($self->src(), 'packages');
 4316: 
 4317: 	if ($partorder) {
 4318: 	    my @parts;
 4319: 	    for my $part (split (/,/,$partorder)) {
 4320: 		if (!Apache::loncommon::check_if_partid_hidden($part, $self->symb())) {
 4321: 		    push @parts, $part;
 4322: 		    $parts{$part} = 1;
 4323: 		}
 4324: 	    }
 4325: 	    $self->{PARTS} = \@parts;
 4326: 	} else {
 4327: 	    if (!$metadata) {
 4328: 		$self->{RESOURCE_ERROR} = 1;
 4329: 		$self->{PARTS} = [];
 4330: 		$self->{PART_TYPE} = {};
 4331: 		return;
 4332: 	    }
 4333: 	    foreach my $entry (split(/\,/,$metadata)) {
 4334: 		if ($entry =~ /^(?:part|Task)_(.*)$/) {
 4335: 		    my $part = $1;
 4336: 		    # This floods the logs if it blows up
 4337: 		    if (defined($parts{$part})) {
 4338: 			&Apache::lonnet::logthis("$part multiply defined in metadata for " . $self->symb());
 4339: 		    }
 4340: 		    
 4341: 		    # check to see if part is turned off.
 4342: 		    
 4343: 		    if (!Apache::loncommon::check_if_partid_hidden($part, $self->symb())) {
 4344: 			$parts{$part} = 1;
 4345: 		    }
 4346: 		}
 4347: 	    }
 4348: 	    my @sortedParts = sort keys %parts;
 4349: 	    $self->{PARTS} = \@sortedParts;
 4350:         }
 4351:         
 4352: 
 4353:         # These hashes probably do not need names that end with "Hash"....
 4354:         my %responseIdHash;
 4355:         my %responseTypeHash;
 4356: 
 4357: 
 4358:         # Init the responseIdHash
 4359:         foreach my $part (@{$self->{PARTS}}) {
 4360:             $responseIdHash{$part} = [];
 4361:         }
 4362: 
 4363:         # Now, the unfortunate thing about this is that parts, part name, and
 4364:         # response id are delimited by underscores, but both the part
 4365:         # name and response id can themselves have underscores in them.
 4366:         # So we have to use our knowlege of part names to figure out 
 4367:         # where the part names begin and end, and even then, it is possible
 4368:         # to construct ambiguous situations.
 4369:         foreach my $data (split /,/, $metadata) {
 4370:             if ($data =~ /^([a-zA-Z]+)response_(.*)/
 4371: 		|| $data =~ /^(Task)_(.*)/) {
 4372:                 my $responseType = $1;
 4373:                 my $partStuff = $2;
 4374:                 my $partIdSoFar = '';
 4375:                 my @partChunks = split /_/, $partStuff;
 4376:                 my $i = 0;
 4377:                 for ($i = 0; $i < scalar(@partChunks); $i++) {
 4378:                     if ($partIdSoFar) { $partIdSoFar .= '_'; }
 4379:                     $partIdSoFar .= $partChunks[$i];
 4380:                     if ($parts{$partIdSoFar}) {
 4381:                         my @otherChunks = @partChunks[$i+1..$#partChunks];
 4382:                         my $responseId = join('_', @otherChunks);
 4383: 			if ($self->is_task()) {
 4384: 			    push(@{$responseIdHash{$partIdSoFar}},
 4385: 				 $partIdSoFar);
 4386: 			} else {
 4387: 			    push(@{$responseIdHash{$partIdSoFar}},
 4388: 				 $responseId);
 4389: 			}
 4390:                         push(@{$responseTypeHash{$partIdSoFar}},
 4391: 			     $responseType);
 4392:                     }
 4393:                 }
 4394:             }
 4395:         }
 4396: 	my $resorder = &Apache::lonnet::metadata($self->src(),'responseorder');
 4397:         #
 4398:         # Reorder the arrays in the %responseIdHash and %responseTypeHash
 4399: 	if ($resorder) {
 4400: 	    my @resorder=split(/,/,$resorder);
 4401: 	    foreach my $part (keys(%responseIdHash)) {
 4402: 		my $i=0;
 4403: 		my %resids = map { ($_,$i++) } @{ $responseIdHash{$part} };
 4404: 		my @neworder;
 4405: 		foreach my $possibleid (@resorder) {
 4406: 		    if (exists($resids{$possibleid})) {
 4407: 			push(@neworder,$resids{$possibleid});
 4408: 		    }
 4409: 		}
 4410: 		my @ids;
 4411: 		my @type;
 4412: 		foreach my $element (@neworder) {
 4413: 		    push (@ids,$responseIdHash{$part}->[$element]);
 4414: 		    push (@type,$responseTypeHash{$part}->[$element]);
 4415: 		}
 4416: 		$responseIdHash{$part}=\@ids;
 4417: 		$responseTypeHash{$part}=\@type;
 4418: 	    }
 4419: 	}
 4420:         $self->{RESPONSE_IDS} = \%responseIdHash;
 4421:         $self->{RESPONSE_TYPES} = \%responseTypeHash;
 4422:     }
 4423: 
 4424:     return;
 4425: }
 4426: 
 4427: =pod
 4428: 
 4429: =head2 Resource Status
 4430: 
 4431: Problem resources have status information, reflecting their various
 4432: dates and completion statuses.
 4433: 
 4434: There are two aspects to the status: the date-related information and
 4435: the completion information.
 4436: 
 4437: Idiomatic usage of these two methods would probably look something
 4438: like
 4439: 
 4440:  foreach my $part ($resource->parts()) {
 4441:     my $dateStatus = $resource->getDateStatus($part);
 4442:     my $completionStatus = $resource->getCompletionStatus($part);
 4443: 
 4444:     or
 4445: 
 4446:     my $status = $resource->status($part);
 4447: 
 4448:     ... use it here ...
 4449:  }
 4450: 
 4451: Which you use depends on exactly what you are looking for. The
 4452: status() function has been optimized for the nav maps display and may
 4453: not precisely match what you need elsewhere.
 4454: 
 4455: The symbolic constants shown below can be accessed through the
 4456: resource object: C<$res->OPEN>.
 4457: 
 4458: =over 4
 4459: 
 4460: =item * B<getDateStatus>($part):
 4461: 
 4462: ($part defaults to 0). A convenience function that returns a symbolic
 4463: constant telling you about the date status of the part. The possible
 4464: return values are:
 4465: 
 4466: =back
 4467: 
 4468: B<Date Codes>
 4469: 
 4470: =over 4
 4471: 
 4472: =item * B<OPEN_LATER>:
 4473: 
 4474: The problem will be opened later.
 4475: 
 4476: =item * B<OPEN>:
 4477: 
 4478: Open and not yet due.
 4479: 
 4480: 
 4481: =item * B<PAST_DUE_ANSWER_LATER>:
 4482: 
 4483: The due date has passed, but the answer date has not yet arrived.
 4484: 
 4485: =item * B<PAST_DUE_NO_ANSWER>:
 4486: 
 4487: The due date has passed and there is no answer opening date set.
 4488: 
 4489: =item * B<ANSWER_OPEN>:
 4490: 
 4491: The answer date is here.
 4492: 
 4493: =item * B<NETWORK_FAILURE>:
 4494: 
 4495: The information is unknown due to network failure.
 4496: 
 4497: =back
 4498: 
 4499: =cut
 4500: 
 4501: # Apparently the compiler optimizes these into constants automatically
 4502: sub OPEN_LATER             { return 0; }
 4503: sub OPEN                   { return 1; }
 4504: sub PAST_DUE_NO_ANSWER     { return 2; }
 4505: sub PAST_DUE_ANSWER_LATER  { return 3; }
 4506: sub ANSWER_OPEN            { return 4; }
 4507: sub NOTHING_SET            { return 5; } 
 4508: sub NETWORK_FAILURE        { return 100; }
 4509: 
 4510: # getDateStatus gets the date status for a given problem part. 
 4511: # Because answer date, due date, and open date are fully independent
 4512: # (i.e., it is perfectly possible to *only* have an answer date), 
 4513: # we have to completely cover the 3x3 maxtrix of (answer, due, open) x
 4514: # (past, future, none given). This function handles this with a decision
 4515: # tree. Read the comments to follow the decision tree.
 4516: 
 4517: sub getDateStatus {
 4518:     my $self = shift;
 4519:     my $part = shift;
 4520:     $part = "0" if (!defined($part));
 4521: 
 4522:     # Always return network failure if there was one.
 4523:     return $self->NETWORK_FAILURE if ($self->{NAV_MAP}->{NETWORK_FAILURE});
 4524: 
 4525:     my $now = time();
 4526: 
 4527:     my $open = $self->opendate($part);
 4528:     my $due = $self->duedate($part);
 4529:     my $answer = $self->answerdate($part);
 4530: 
 4531:     if (!$open && !$due && !$answer) {
 4532:         # no data on the problem at all
 4533:         # should this be the same as "open later"? think multipart.
 4534:         return $self->NOTHING_SET;
 4535:     }
 4536:     if (!$open || $now < $open) {return $self->OPEN_LATER}
 4537:     if (!$due || $now < $due) {return $self->OPEN}
 4538:     if ($answer && $now < $answer) {return $self->PAST_DUE_ANSWER_LATER}
 4539:     if ($answer) { return $self->ANSWER_OPEN; }
 4540:     return PAST_DUE_NO_ANSWER;
 4541: }
 4542: 
 4543: =pod
 4544: 
 4545: B<>
 4546: 
 4547: =over 4
 4548: 
 4549: =item * B<getCompletionStatus>($part):
 4550: 
 4551: ($part defaults to 0.) A convenience function that returns a symbolic
 4552: constant telling you about the completion status of the part, with the
 4553: following possible results:
 4554: 
 4555: =back
 4556: 
 4557: B<Completion Codes>
 4558: 
 4559: =over 4
 4560: 
 4561: =item * B<NOT_ATTEMPTED>:
 4562: 
 4563: Has not been attempted at all.
 4564: 
 4565: =item * B<INCORRECT>:
 4566: 
 4567: Attempted, but wrong by student.
 4568: 
 4569: =item * B<INCORRECT_BY_OVERRIDE>:
 4570: 
 4571: Attempted, but wrong by instructor override.
 4572: 
 4573: =item * B<CORRECT>:
 4574: 
 4575: Correct or correct by instructor.
 4576: 
 4577: =item * B<CORRECT_BY_OVERRIDE>:
 4578: 
 4579: Correct by instructor override.
 4580: 
 4581: =item * B<EXCUSED>:
 4582: 
 4583: Excused. Not yet implemented.
 4584: 
 4585: =item * B<NETWORK_FAILURE>:
 4586: 
 4587: Information not available due to network failure.
 4588: 
 4589: =item * B<ATTEMPTED>:
 4590: 
 4591: Attempted, and not yet graded.
 4592: 
 4593: =back
 4594: 
 4595: =cut
 4596: 
 4597: sub NOT_ATTEMPTED         { return 10; }
 4598: sub INCORRECT             { return 11; }
 4599: sub INCORRECT_BY_OVERRIDE { return 12; }
 4600: sub CORRECT               { return 13; }
 4601: sub CORRECT_BY_OVERRIDE   { return 14; }
 4602: sub EXCUSED               { return 15; }
 4603: sub ATTEMPTED             { return 16; }
 4604: 
 4605: sub getCompletionStatus {
 4606:     my $self = shift;
 4607:     my $part = shift;
 4608:     return $self->NETWORK_FAILURE if ($self->{NAV_MAP}->{NETWORK_FAILURE});
 4609: 
 4610:     my $status = $self->queryRestoreHash('solved', $part);
 4611: 
 4612:     # Left as separate if statements in case we ever do more with this
 4613:     if ($status eq 'correct_by_student') {return $self->CORRECT;}
 4614:     if ($status eq 'correct_by_scantron') {return $self->CORRECT;}
 4615:     if ($status eq 'correct_by_override') {
 4616: 	return $self->CORRECT_BY_OVERRIDE;
 4617:     }
 4618:     if ($status eq 'incorrect_attempted') {return $self->INCORRECT; }
 4619:     if ($status eq 'incorrect_by_override') {return $self->INCORRECT_BY_OVERRIDE; }
 4620:     if ($status eq 'excused') {return $self->EXCUSED; }
 4621:     if ($status eq 'ungraded_attempted') {return $self->ATTEMPTED; }
 4622:     return $self->NOT_ATTEMPTED;
 4623: }
 4624: 
 4625: sub queryRestoreHash {
 4626:     my $self = shift;
 4627:     my $hashentry = shift;
 4628:     my $part = shift;
 4629:     $part = "0" if (!defined($part) || $part eq '');
 4630:     return $self->NETWORK_FAILURE if ($self->{NAV_MAP}->{NETWORK_FAILURE});
 4631: 
 4632:     $self->getReturnHash();
 4633: 
 4634:     return $self->{RETURN_HASH}->{'resource.'.$part.'.'.$hashentry};
 4635: }
 4636: 
 4637: =pod
 4638: 
 4639: B<Composite Status>
 4640: 
 4641: Along with directly returning the date or completion status, the
 4642: resource object includes a convenience function B<status>() that will
 4643: combine the two status tidbits into one composite status that can
 4644: represent the status of the resource as a whole. This method represents
 4645: the concept of the thing we want to display to the user on the nav maps
 4646: screen, which is a combination of completion and open status. The precise logic is
 4647: documented in the comments of the status method. The following results
 4648: may be returned, all available as methods on the resource object
 4649: ($res->NETWORK_FAILURE): In addition to the return values that match
 4650: the date or completion status, this function can return "ANSWER_SUBMITTED"
 4651: if that problemstatus parameter value is set to No, suppressing the
 4652: incorrect/correct feedback.
 4653: 
 4654: =over 4
 4655: 
 4656: =item * B<NETWORK_FAILURE>:
 4657: 
 4658: The network has failed and the information is not available.
 4659: 
 4660: =item * B<NOTHING_SET>:
 4661: 
 4662: No dates have been set for this problem (part) at all. (Because only
 4663: certain parts of a multi-part problem may be assigned, this can not be
 4664: collapsed into "open later", as we do not know a given part will EVER
 4665: be opened. For single part, this is the same as "OPEN_LATER".)
 4666: 
 4667: =item * B<CORRECT>:
 4668: 
 4669: For any reason at all, the part is considered correct.
 4670: 
 4671: =item * B<EXCUSED>:
 4672: 
 4673: For any reason at all, the problem is excused.
 4674: 
 4675: =item * B<PAST_DUE_NO_ANSWER>:
 4676: 
 4677: The problem is past due, not considered correct, and no answer date is
 4678: set.
 4679: 
 4680: =item * B<PAST_DUE_ANSWER_LATER>:
 4681: 
 4682: The problem is past due, not considered correct, and an answer date in
 4683: the future is set.
 4684: 
 4685: =item * B<ANSWER_OPEN>:
 4686: 
 4687: The problem is past due, not correct, and the answer is now available.
 4688: 
 4689: =item * B<OPEN_LATER>:
 4690: 
 4691: The problem is not yet open.
 4692: 
 4693: =item * B<TRIES_LEFT>:
 4694: 
 4695: The problem is open, has been tried, is not correct, but there are
 4696: tries left.
 4697: 
 4698: =item * B<INCORRECT>:
 4699: 
 4700: The problem is open, and all tries have been used without getting the
 4701: correct answer.
 4702: 
 4703: =item * B<OPEN>:
 4704: 
 4705: The item is open and not yet tried.
 4706: 
 4707: =item * B<ATTEMPTED>:
 4708: 
 4709: The problem has been attempted.
 4710: 
 4711: =item * B<ANSWER_SUBMITTED>:
 4712: 
 4713: An answer has been submitted, but the student should not see it.
 4714: 
 4715: =back
 4716: 
 4717: =cut
 4718: 
 4719: sub TRIES_LEFT       { return 20; }
 4720: sub ANSWER_SUBMITTED { return 21; }
 4721: sub PARTIALLY_CORRECT{ return 22; }
 4722: 
 4723: sub status {
 4724:     my $self = shift;
 4725:     my $part = shift;
 4726:     if (!defined($part)) { $part = "0"; }
 4727:     my $completionStatus = $self->getCompletionStatus($part);
 4728:     my $dateStatus = $self->getDateStatus($part);
 4729: 
 4730:     # What we have is a two-dimensional matrix with 4 entries on one
 4731:     # dimension and 5 entries on the other, which we want to colorize,
 4732:     # plus network failure and "no date data at all".
 4733: 
 4734:     #if ($self->{RESOURCE_ERROR}) { return NETWORK_FAILURE; }
 4735:     if ($completionStatus == NETWORK_FAILURE) { return NETWORK_FAILURE; }
 4736: 
 4737:     my $suppressFeedback = 0;
 4738:     if (($self->problemstatus($part) eq 'no') ||
 4739:         ($self->problemstatus($part) eq 'no_feedback_ever')) {
 4740:         $suppressFeedback = 1;
 4741:     }
 4742:     # If there's an answer date and we're past it, don't
 4743:     # suppress the feedback; student should know
 4744:     if ($self->duedate($part) && $self->duedate($part) < time() &&
 4745: 	$self->answerdate($part) && $self->answerdate($part) < time()) {
 4746: 	$suppressFeedback = 0;
 4747:     }
 4748: 
 4749:     # There are a few whole rows we can dispose of:
 4750:     if ($completionStatus == CORRECT ||
 4751:         $completionStatus == CORRECT_BY_OVERRIDE ) {
 4752: 	if ( $suppressFeedback ) { return ANSWER_SUBMITTED }
 4753: 	my $awarded=$self->awarded($part);
 4754: 	if ($awarded < 1 && $awarded > 0) {
 4755:             return PARTIALLY_CORRECT;
 4756: 	} elsif ($awarded<1) {
 4757: 	    return INCORRECT;
 4758: 	}
 4759: 	return CORRECT; 
 4760:     }
 4761: 
 4762:     # If it's WRONG... and not open
 4763:     if ( ($completionStatus == INCORRECT || 
 4764: 	  $completionStatus == INCORRECT_BY_OVERRIDE)
 4765: 	 && (!$self->opendate($part) ||  $self->opendate($part) > time()) ) {
 4766: 	return INCORRECT;
 4767:     }
 4768: 
 4769:     if ($completionStatus == ATTEMPTED) {
 4770:         return ATTEMPTED;
 4771:     }
 4772: 
 4773:     # If it's EXCUSED, then return that no matter what
 4774:     if ($completionStatus == EXCUSED) {
 4775:         return EXCUSED; 
 4776:     }
 4777: 
 4778:     if ($dateStatus == NOTHING_SET) {
 4779:         return NOTHING_SET;
 4780:     }
 4781: 
 4782:     # Now we're down to a 4 (incorrect, incorrect_override, not_attempted)
 4783:     # by 4 matrix (date statuses).
 4784: 
 4785:     if ($dateStatus == PAST_DUE_ANSWER_LATER ||
 4786:         $dateStatus == PAST_DUE_NO_ANSWER ) {
 4787:         return $suppressFeedback ? ANSWER_SUBMITTED : $dateStatus; 
 4788:     }
 4789: 
 4790:     if ($dateStatus == ANSWER_OPEN) {
 4791:         return ANSWER_OPEN;
 4792:     }
 4793: 
 4794:     # Now: (incorrect, incorrect_override, not_attempted) x 
 4795:     # (open_later), (open)
 4796:     
 4797:     if ($dateStatus == OPEN_LATER) {
 4798:         return OPEN_LATER;
 4799:     }
 4800: 
 4801:     # If it's WRONG...
 4802:     if ($completionStatus == INCORRECT || $completionStatus == INCORRECT_BY_OVERRIDE) {
 4803:         # and there are TRIES LEFT:
 4804:         if ($self->tries($part) < $self->maxtries($part) || !$self->maxtries($part)) {
 4805:             return $suppressFeedback ? ANSWER_SUBMITTED : TRIES_LEFT;
 4806:         }
 4807:         return $suppressFeedback ? ANSWER_SUBMITTED : INCORRECT; # otherwise, return orange; student can't fix this
 4808:     }
 4809: 
 4810:     # Otherwise, it's untried and open
 4811:     return OPEN; 
 4812: }
 4813: 
 4814: sub CLOSED { return 23; }
 4815: sub ERROR { return 24; }
 4816: 
 4817: =pod
 4818: 
 4819: B<Simple Status>
 4820: 
 4821: Convenience method B<simpleStatus> provides a "simple status" for the resource.
 4822: "Simple status" corresponds to "which icon is shown on the
 4823: Navmaps". There are six "simple" statuses:
 4824: 
 4825: =over 4
 4826: 
 4827: =item * B<CLOSED>: The problem is currently closed. (No icon shown.)
 4828: 
 4829: =item * B<OPEN>: The problem is open and unattempted.
 4830: 
 4831: =item * B<CORRECT>: The problem is correct for any reason.
 4832: 
 4833: =item * B<INCORRECT>: The problem is incorrect and can still be
 4834: completed successfully.
 4835: 
 4836: =item * B<ATTEMPTED>: The problem has been attempted, but the student
 4837: does not know if they are correct. (The ellipsis icon.)
 4838: 
 4839: =item * B<ERROR>: There is an error retrieving information about this
 4840: problem.
 4841: 
 4842: =back
 4843: 
 4844: =cut
 4845: 
 4846: # This hash maps the composite status to this simple status, and
 4847: # can be used directly, if you like
 4848: my %compositeToSimple = 
 4849:     (
 4850:       NETWORK_FAILURE()       => ERROR,
 4851:       NOTHING_SET()           => CLOSED,
 4852:       CORRECT()               => CORRECT,
 4853:       PARTIALLY_CORRECT()     => PARTIALLY_CORRECT,
 4854:       EXCUSED()               => CORRECT,
 4855:       PAST_DUE_NO_ANSWER()    => INCORRECT,
 4856:       PAST_DUE_ANSWER_LATER() => INCORRECT,
 4857:       ANSWER_OPEN()           => INCORRECT,
 4858:       OPEN_LATER()            => CLOSED,
 4859:       TRIES_LEFT()            => OPEN,
 4860:       INCORRECT()             => INCORRECT,
 4861:       OPEN()                  => OPEN,
 4862:       ATTEMPTED()             => ATTEMPTED,
 4863:       ANSWER_SUBMITTED()      => ATTEMPTED
 4864:      );
 4865: 
 4866: sub simpleStatus {
 4867:     my $self = shift;
 4868:     my $part = shift;
 4869:     my $status = $self->status($part);
 4870:     return $compositeToSimple{$status};
 4871: }
 4872: 
 4873: =pod
 4874: 
 4875: B<simpleStatusCount> will return an array reference containing, in
 4876: this order, the number of OPEN, CLOSED, CORRECT, INCORRECT, ATTEMPTED,
 4877: and ERROR parts the given problem has.
 4878: 
 4879: =cut
 4880:     
 4881: # This maps the status to the slot we want to increment
 4882: my %statusToSlotMap = 
 4883:     (
 4884:      OPEN()      => 0,
 4885:      CLOSED()    => 1,
 4886:      CORRECT()   => 2,
 4887:      INCORRECT() => 3,
 4888:      ATTEMPTED() => 4,
 4889:      ERROR()     => 5
 4890:      );
 4891: 
 4892: sub statusToSlot { return $statusToSlotMap{shift()}; }
 4893: 
 4894: sub simpleStatusCount {
 4895:     my $self = shift;
 4896: 
 4897:     my @counts = (0, 0, 0, 0, 0, 0, 0);
 4898:     foreach my $part (@{$self->parts()}) {
 4899: 	$counts[$statusToSlotMap{$self->simpleStatus($part)}]++;
 4900:     }
 4901: 
 4902:     return \@counts;
 4903: }
 4904: 
 4905: =pod
 4906: 
 4907: B<Completable>
 4908: 
 4909: The completable method represents the concept of I<whether the student can
 4910: currently do the problem>. If the student can do the problem, which means
 4911: that it is open, there are tries left, and if the problem is manually graded
 4912: or the grade is suppressed via problemstatus, the student has not tried it
 4913: yet, then the method returns 1. Otherwise, it returns 0, to indicate that 
 4914: either the student has tried it and there is no feedback, or that for
 4915: some reason it is no longer completable (not open yet, successfully completed,
 4916: out of tries, etc.). As an example, this is used as the filter for the
 4917: "Uncompleted Homework" option for the nav maps.
 4918: 
 4919: If this does not quite meet your needs, do not fiddle with it (unless you are
 4920: fixing it to better match the student's conception of "completable" because
 4921: it's broken somehow)... make a new method.
 4922: 
 4923: =cut
 4924: 
 4925: sub completable {
 4926:     my $self = shift;
 4927:     if (!$self->is_problem()) { return 0; }
 4928:     my $partCount = $self->countParts();
 4929: 
 4930:     foreach my $part (@{$self->parts()}) {
 4931:         if ($part eq '0' && $partCount != 1) { next; }
 4932:         my $status = $self->status($part);
 4933:         # "If any of the parts are open, or have tries left (implies open),
 4934:         # and it is not "attempted" (manually graded problem), it is
 4935:         # not "complete"
 4936: 	if ($self->getCompletionStatus($part) == ATTEMPTED() ||
 4937: 	    $status == ANSWER_SUBMITTED() ) {
 4938: 	    # did this part already, as well as we can
 4939: 	    next;
 4940: 	}
 4941: 	if ($status == OPEN() || $status == TRIES_LEFT()) {
 4942: 	    return 1;
 4943: 	}
 4944:     }
 4945:         
 4946:     # If all the parts were complete, so was this problem.
 4947:     return 0;
 4948: }
 4949: 
 4950: =pod
 4951: 
 4952: =head2 Resource/Nav Map Navigation
 4953: 
 4954: =over 4
 4955: 
 4956: =item * B<getNext>():
 4957: 
 4958: Retreive an array of the possible next resources after this
 4959: one. Always returns an array, even in the one- or zero-element case.
 4960: 
 4961: =item * B<getPrevious>():
 4962: 
 4963: Retreive an array of the possible previous resources from this
 4964: one. Always returns an array, even in the one- or zero-element case.
 4965: 
 4966: =cut
 4967: 
 4968: sub getNext {
 4969:     my $self = shift;
 4970:     my @branches;
 4971:     my $to = $self->to();
 4972:     foreach my $branch ( split(/,/, $to) ) {
 4973:         my $choice = $self->{NAV_MAP}->getById($branch);
 4974:         #if (!$choice->condition()) { next; }
 4975:         my $next = $choice->goesto();
 4976:         $next = $self->{NAV_MAP}->getById($next);
 4977: 
 4978:         push @branches, $next;
 4979:     }
 4980:     return \@branches;
 4981: }
 4982: 
 4983: sub getPrevious {
 4984:     my $self = shift;
 4985:     my @branches;
 4986:     my $from = $self->from();
 4987:     foreach my $branch ( split /,/, $from) {
 4988:         my $choice = $self->{NAV_MAP}->getById($branch);
 4989:         my $prev = $choice->comesfrom();
 4990:         $prev = $self->{NAV_MAP}->getById($prev);
 4991: 
 4992:         push @branches, $prev;
 4993:     }
 4994:     return \@branches;
 4995: }
 4996: 
 4997: sub browsePriv {
 4998:     my $self = shift;
 4999:     if (defined($self->{BROWSE_PRIV})) {
 5000:         return $self->{BROWSE_PRIV};
 5001:     }
 5002: 
 5003:     $self->{BROWSE_PRIV} = &Apache::lonnet::allowed('bre',$self->src(),
 5004: 						    $self->symb());
 5005: }
 5006: 
 5007: =pod
 5008: 
 5009: =back
 5010: 
 5011: =cut
 5012: 
 5013: 1;
 5014: 
 5015: __END__
 5016: 
 5017: 

FreeBSD-CVSweb <freebsd-cvsweb@FreeBSD.org>