File:
[LON-CAPA] /
loncom /
interface /
lonhelper.pm
Revision
1.11:
download - view:
text,
annotated -
select for diffs
Tue Apr 15 19:10:00 2003 UTC (21 years, 1 month ago) by
bowersj2
Branches:
MAIN
CVS tags:
HEAD
* "die" now explicitly used when subroutine compilations fail so the
web server error log has an indication what the problem is, instead of
silently failing.
* Added section choosing routine. May not completely work yet.
* Added eval tag, which allows the user to programmatically specify a
message to print, which turned out to be necessary.
1: # The LearningOnline Network with CAPA
2: # .helper XML handler to implement the LON-CAPA helper
3: #
4: # $Id: lonhelper.pm,v 1.11 2003/04/15 19:10:00 bowersj2 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: # (Page Handler
29: #
30: # (.helper handler
31: #
32:
33: =pod
34:
35: =head1 lonhelper - HTML Helper framework for LON-CAPA
36:
37: Helpers, often known as "wizards", are well-established UI widgets that users
38: feel comfortable with. It can take a complicated multidimensional problem the
39: user has and turn it into a series of bite-sized one-dimensional questions.
40:
41: For developers, helpers provide an easy way to bundle little bits of functionality
42: for the user, without having to write the tedious state-maintenence code.
43:
44: Helpers are defined as XML documents, placed in the /home/httpd/html/adm/helpers
45: directory and having the .helper file extension. For examples, see that directory.
46:
47: All classes are in the Apache::lonhelper namespace.
48:
49: =head2 lonhelper XML file format
50:
51: A helper consists of a top-level <helper> tag which contains a series of states.
52: Each state contains one or more state elements, which are what the user sees, like
53: messages, resource selections, or date queries.
54:
55: The helper tag is required to have one attribute, "title", which is the name
56: of the helper itself, such as "Parameter helper".
57:
58: =head2 State tags
59:
60: State tags are required to have an attribute "name", which is the symbolic
61: name of the state and will not be directly seen by the user. The helper is
62: required to have one state named "START", which is the state the helper
63: will start with. By convention, this state should clearly describe what
64: the helper will do for the user, and may also include the first information
65: entry the user needs to do for the helper.
66:
67: State tags are also required to have an attribute "title", which is the
68: human name of the state, and will be displayed as the header on top of
69: the screen for the user.
70:
71: =head2 Example Helper Skeleton
72:
73: An example of the tags so far:
74:
75: <helper title="Example Helper">
76: <state name="START" title="Demonstrating the Example Helper">
77: <!-- notice this is the START state the wizard requires -->
78: </state>
79: <state name="GET_NAME" title="Enter Student Name">
80: </state>
81: </helper>
82:
83: Of course this does nothing. In order for the wizard to do something, it is
84: necessary to put actual elements into the wizard. Documentation for each
85: of these elements follows.
86:
87: =cut
88:
89: package Apache::lonhelper;
90: use Apache::Constants qw(:common);
91: use Apache::File;
92: use Apache::lonxml;
93:
94: # Register all the tags with the helper, so the helper can
95: # push and pop them
96:
97: my @helperTags;
98:
99: sub register {
100: my ($namespace, @tags) = @_;
101:
102: for my $tag (@tags) {
103: push @helperTags, [$namespace, $tag];
104: }
105: }
106:
107: BEGIN {
108: Apache::lonxml::register('Apache::lonhelper',
109: ('helper'));
110: register('Apache::lonhelper', ('state'));
111: }
112:
113: # Since all helpers are only three levels deep (helper tag, state tag,
114: # substate type), it's easier and more readble to explicitly track
115: # those three things directly, rather then futz with the tag stack
116: # every time.
117: my $helper;
118: my $state;
119: my $substate;
120: # To collect parameters, the contents of the subtags are collected
121: # into this paramHash, then passed to the element object when the
122: # end of the element tag is located.
123: my $paramHash;
124:
125: sub handler {
126: my $r = shift;
127: $ENV{'request.uri'} = $r->uri();
128: my $filename = '/home/httpd/html' . $r->uri();
129: my $fh = Apache::File->new($filename);
130: my $file;
131: read $fh, $file, 100000000;
132:
133: Apache::loncommon::get_unprocessed_cgi($ENV{QUERY_STRING});
134:
135: # Send header, don't cache this page
136: if ($r->header_only) {
137: if ($ENV{'browser.mathml'}) {
138: $r->content_type('text/xml');
139: } else {
140: $r->content_type('text/html');
141: }
142: $r->send_http_header;
143: return OK;
144: }
145: if ($ENV{'browser.mathml'}) {
146: $r->content_type('text/xml');
147: } else {
148: $r->content_type('text/html');
149: }
150: $r->send_http_header;
151: $r->rflush();
152:
153: # Discard result, we just want the objects that get created by the
154: # xml parsing
155: &Apache::lonxml::xmlparse($r, 'helper', $file);
156:
157: $r->print($helper->display());
158: return OK;
159: }
160:
161: sub start_helper {
162: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
163:
164: if ($target ne 'helper') {
165: return '';
166: }
167:
168: for my $tagList (@helperTags) {
169: Apache::lonxml::register($tagList->[0], $tagList->[1]);
170: }
171:
172: $helper = Apache::lonhelper::helper->new($token->[2]{'title'});
173: return '';
174: }
175:
176: sub end_helper {
177: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
178:
179: if ($target ne 'helper') {
180: return '';
181: }
182:
183: for my $tagList (@helperTags) {
184: Apache::lonxml::deregister($tagList->[0], $tagList->[1]);
185: }
186:
187: return '';
188: }
189:
190: sub start_state {
191: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
192:
193: if ($target ne 'helper') {
194: return '';
195: }
196:
197: $state = Apache::lonhelper::state->new($token->[2]{'name'},
198: $token->[2]{'title'});
199: return '';
200: }
201:
202: # don't need this, so ignore it
203: sub end_state {
204: return '';
205: }
206:
207: 1;
208:
209: package Apache::lonhelper::helper;
210:
211: use Digest::MD5 qw(md5_hex);
212: use HTML::Entities;
213: use Apache::loncommon;
214: use Apache::File;
215:
216: sub new {
217: my $proto = shift;
218: my $class = ref($proto) || $proto;
219: my $self = {};
220:
221: $self->{TITLE} = shift;
222:
223: # If there is a state from the previous form, use that. If there is no
224: # state, use the start state parameter.
225: if (defined $ENV{"form.CURRENT_STATE"})
226: {
227: $self->{STATE} = $ENV{"form.CURRENT_STATE"};
228: }
229: else
230: {
231: $self->{STATE} = "START";
232: }
233:
234: $self->{TOKEN} = $ENV{'form.TOKEN'};
235: # If a token was passed, we load that in. Otherwise, we need to create a
236: # new storage file
237: # Tried to use standard Tie'd hashes, but you can't seem to take a
238: # reference to a tied hash and write to it. I'd call that a wart.
239: if ($self->{TOKEN}) {
240: # Validate the token before trusting it
241: if ($self->{TOKEN} !~ /^[a-f0-9]{32}$/) {
242: # Not legit. Return nothing and let all hell break loose.
243: # User shouldn't be doing that!
244: return undef;
245: }
246:
247: # Get the hash.
248: $self->{FILENAME} = $Apache::lonnet::tmpdir . md5_hex($self->{TOKEN}); # Note the token is not the literal file
249:
250: my $file = Apache::File->new($self->{FILENAME});
251: my $contents = <$file>;
252:
253: # Now load in the contents
254: for my $value (split (/&/, $contents)) {
255: my ($name, $value) = split(/=/, $value);
256: $value =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C", hex($1))/eg;
257: $self->{VARS}->{$name} = $value;
258: }
259:
260: $file->close();
261: } else {
262: # Only valid if we're just starting.
263: if ($self->{STATE} ne 'START') {
264: return undef;
265: }
266: # Must create the storage
267: $self->{TOKEN} = md5_hex($ENV{'user.name'} . $ENV{'user.domain'} .
268: time() . rand());
269: $self->{FILENAME} = $Apache::lonnet::tmpdir . md5_hex($self->{TOKEN});
270: }
271:
272: # OK, we now have our persistent storage.
273:
274: if (defined $ENV{"form.RETURN_PAGE"})
275: {
276: $self->{RETURN_PAGE} = $ENV{"form.RETURN_PAGE"};
277: }
278: else
279: {
280: $self->{RETURN_PAGE} = $ENV{REFERER};
281: }
282:
283: $self->{STATES} = {};
284: $self->{DONE} = 0;
285:
286: # Used by various helpers for various things; see lonparm.helper
287: # for an example.
288: $self->{DATA} = {};
289:
290: bless($self, $class);
291: return $self;
292: }
293:
294: # Private function; returns a string to construct the hidden fields
295: # necessary to have the helper track state.
296: sub _saveVars {
297: my $self = shift;
298: my $result = "";
299: $result .= '<input type="hidden" name="CURRENT_STATE" value="' .
300: HTML::Entities::encode($self->{STATE}) . "\" />\n";
301: $result .= '<input type="hidden" name="TOKEN" value="' .
302: $self->{TOKEN} . "\" />\n";
303: $result .= '<input type="hidden" name="RETURN_PAGE" value="' .
304: HTML::Entities::encode($self->{RETURN_PAGE}) . "\" />\n";
305:
306: return $result;
307: }
308:
309: # Private function: Create the querystring-like representation of the stored
310: # data to write to disk.
311: sub _varsInFile {
312: my $self = shift;
313: my @vars = ();
314: for my $key (keys %{$self->{VARS}}) {
315: push @vars, &Apache::lonnet::escape($key) . '=' .
316: &Apache::lonnet::escape($self->{VARS}->{$key});
317: }
318: return join ('&', @vars);
319: }
320:
321: # Use this to declare variables.
322: # FIXME: Document this
323: sub declareVar {
324: my $self = shift;
325: my $var = shift;
326:
327: if (!defined($self->{VARS}->{$var})) {
328: $self->{VARS}->{$var} = '';
329: }
330:
331: my $envname = 'form.' . $var . '.forminput';
332: if (defined($ENV{$envname})) {
333: $self->{VARS}->{$var} = $ENV{$envname};
334: }
335: }
336:
337: sub changeState {
338: my $self = shift;
339: $self->{STATE} = shift;
340: }
341:
342: sub registerState {
343: my $self = shift;
344: my $state = shift;
345:
346: my $stateName = $state->name();
347: $self->{STATES}{$stateName} = $state;
348: }
349:
350: # Done in four phases
351: # 1: Do the post processing for the previous state.
352: # 2: Do the preprocessing for the current state.
353: # 3: Check to see if state changed, if so, postprocess current and move to next.
354: # Repeat until state stays stable.
355: # 4: Render the current state to the screen as an HTML page.
356: sub display {
357: my $self = shift;
358:
359: my $result = "";
360:
361: # Phase 1: Post processing for state of previous screen (which is actually
362: # the "current state" in terms of the helper variables), if it wasn't the
363: # beginning state.
364: if ($self->{STATE} ne "START" || $ENV{"form.SUBMIT"} eq "Next ->") {
365: my $prevState = $self->{STATES}{$self->{STATE}};
366: $prevState->postprocess();
367: }
368:
369: # Note, to handle errors in a state's input that a user must correct,
370: # do not transition in the postprocess, and force the user to correct
371: # the error.
372:
373: # Phase 2: Preprocess current state
374: my $startState = $self->{STATE};
375: my $state = $self->{STATES}{$startState};
376:
377: # Error checking; it is intended that the developer will have
378: # checked all paths and the user can't see this!
379: if (!defined($state)) {
380: $result .="Error! The state ". $startState ." is not defined.";
381: return $result;
382: }
383: $state->preprocess();
384:
385: # Phase 3: While the current state is different from the previous state,
386: # keep processing.
387: while ( $startState ne $self->{STATE} )
388: {
389: $startState = $self->{STATE};
390: $state = $self->{STATES}{$startState};
391: $state->preprocess();
392: }
393:
394: # Phase 4: Display.
395: my $stateTitle = $state->title();
396: my $bodytag = &Apache::loncommon::bodytag("$self->{TITLE}",'','');
397:
398: $result .= <<HEADER;
399: <html>
400: <head>
401: <title>LON-CAPA Helper: $self->{TITLE}</title>
402: </head>
403: $bodytag
404: HEADER
405: if (!$state->overrideForm()) { $result.="<form name='wizform' method='GET'>"; }
406: $result .= <<HEADER;
407: <table border="0"><tr><td>
408: <h2><i>$stateTitle</i></h2>
409: HEADER
410:
411: if (!$state->overrideForm()) {
412: $result .= $self->_saveVars();
413: }
414: $result .= $state->render() . "<p> </p>";
415:
416: if (!$state->overrideForm()) {
417: $result .= '<center>';
418: if ($self->{STATE} ne $self->{START_STATE}) {
419: #$result .= '<input name="SUBMIT" type="submit" value="<- Previous" /> ';
420: }
421: if ($self->{DONE}) {
422: my $returnPage = $self->{RETURN_PAGE};
423: $result .= "<a href=\"$returnPage\">End Helper</a>";
424: }
425: else {
426: $result .= '<input name="back" type="button" ';
427: $result .= 'value="<- Previous" onclick="history.go(-1)" /> ';
428: $result .= '<input name="SUBMIT" type="submit" value="Next ->" />';
429: }
430: $result .= "</center>\n";
431: }
432:
433: foreach my $key (keys %{$self->{VARS}}) {
434: $result .= "|$key| -> " . $self->{VARS}->{$key} . "<br />";
435: }
436:
437: $result .= <<FOOTER;
438: </td>
439: </tr>
440: </table>
441: </form>
442: </body>
443: </html>
444: FOOTER
445:
446: # Handle writing out the vars to the file
447: my $file = Apache::File->new('>'.$self->{FILENAME});
448: print $file $self->_varsInFile();
449:
450: return $result;
451: }
452:
453: 1;
454:
455: package Apache::lonhelper::state;
456:
457: # States bundle things together and are responsible for compositing the
458: # various elements together. It is not generally necessary for users to
459: # use the state object directly, so it is not perldoc'ed.
460:
461: # Basically, all the states do is pass calls to the elements and aggregate
462: # the results.
463:
464: sub new {
465: my $proto = shift;
466: my $class = ref($proto) || $proto;
467: my $self = {};
468:
469: $self->{NAME} = shift;
470: $self->{TITLE} = shift;
471: $self->{ELEMENTS} = [];
472:
473: bless($self, $class);
474:
475: $helper->registerState($self);
476:
477: return $self;
478: }
479:
480: sub name {
481: my $self = shift;
482: return $self->{NAME};
483: }
484:
485: sub title {
486: my $self = shift;
487: return $self->{TITLE};
488: }
489:
490: sub preprocess {
491: my $self = shift;
492: for my $element (@{$self->{ELEMENTS}}) {
493: $element->preprocess();
494: }
495: }
496:
497: # FIXME: Document that all postprocesses must return a true value or
498: # the state transition will be overridden
499: sub postprocess {
500: my $self = shift;
501:
502: # Save the state so we can roll it back if we need to.
503: my $originalState = $helper->{STATE};
504: my $everythingSuccessful = 1;
505:
506: for my $element (@{$self->{ELEMENTS}}) {
507: my $result = $element->postprocess();
508: if (!$result) { $everythingSuccessful = 0; }
509: }
510:
511: # If not all the postprocesses were successful, override
512: # any state transitions that may have occurred. It is the
513: # responsibility of the states to make sure they have
514: # error handling in that case.
515: if (!$everythingSuccessful) {
516: $helper->{STATE} = $originalState;
517: }
518: }
519:
520: sub overrideForm {
521: return 0;
522: }
523:
524: sub addElement {
525: my $self = shift;
526: my $element = shift;
527:
528: push @{$self->{ELEMENTS}}, $element;
529: }
530:
531: sub render {
532: my $self = shift;
533: my @results = ();
534:
535: for my $element (@{$self->{ELEMENTS}}) {
536: push @results, $element->render();
537: }
538: return join("\n", @results);
539: }
540:
541: 1;
542:
543: package Apache::lonhelper::element;
544: # Support code for elements
545:
546: =pod
547:
548: =head2 Element Base Class
549:
550: The Apache::lonhelper::element base class provides support methods for
551: the elements to use, such as a multiple value processer.
552:
553: B<Methods>:
554:
555: =over 4
556:
557: =item * process_multiple_choices(formName, varName): Process the form
558: element named "formName" and place the selected items into the helper
559: variable named varName. This is for things like checkboxes or
560: multiple-selection listboxes where the user can select more then
561: one entry. The selected entries are delimited by triple pipes in
562: the helper variables, like this:
563:
564: CHOICE_1|||CHOICE_2|||CHOICE_3
565:
566: =back
567:
568: =cut
569:
570: BEGIN {
571: &Apache::lonhelper::register('Apache::lonhelper::element',
572: ('nextstate'));
573: }
574:
575: # Because we use the param hash, this is often a sufficent
576: # constructor
577: sub new {
578: my $proto = shift;
579: my $class = ref($proto) || $proto;
580: my $self = $paramHash;
581: bless($self, $class);
582:
583: $self->{PARAMS} = $paramHash;
584: $self->{STATE} = $state;
585: $state->addElement($self);
586:
587: # Ensure param hash is not reused
588: $paramHash = {};
589:
590: return $self;
591: }
592:
593: sub start_nextstate {
594: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
595:
596: if ($target ne 'helper') {
597: return '';
598: }
599:
600: $paramHash->{NEXTSTATE} = &Apache::lonxml::get_all_text('/nextstate',
601: $parser);
602: return '';
603: }
604:
605: sub end_nextstate { return ''; }
606:
607: sub preprocess {
608: return 1;
609: }
610:
611: sub postprocess {
612: return 1;
613: }
614:
615: sub render {
616: return '';
617: }
618:
619: sub process_multiple_choices {
620: my $self = shift;
621: my $formname = shift;
622: my $var = shift;
623:
624: my $formvalue = $ENV{'form.' . $formname};
625: if ($formvalue) {
626: # Must extract values from querystring directly, as there
627: # may be more then one.
628: my @values;
629: for my $formparam (split (/&/, $ENV{QUERY_STRING})) {
630: my ($name, $value) = split(/=/, $formparam);
631: if ($name ne $formname) {
632: next;
633: }
634: $value =~ tr/+/ /;
635: $value =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C", hex($1))/eg;
636: push @values, $value;
637: }
638: $helper->{VARS}->{$var} = join('|||', @values);
639: }
640:
641: return;
642: }
643:
644: 1;
645:
646: package Apache::lonhelper::message;
647:
648: =pod
649:
650: =head2 Element: message
651:
652: Message elements display the contents of their <message_text> tags, and
653: transition directly to the state in the <nextstate> tag. Example:
654:
655: <message>
656: <nextstate>GET_NAME</nextstate>
657: <message_text>This is the <b>message</b> the user will see,
658: <i>HTML allowed</i>.</message_text>
659: </message>
660:
661: This will display the HTML message and transition to the <nextstate> if
662: given. The HTML will be directly inserted into the helper, so if you don't
663: want text to run together, you'll need to manually wrap the <message_text>
664: in <p> tags, or whatever is appropriate for your HTML.
665:
666: Message tags do not add in whitespace, so if you want it, you'll need to add
667: it into states. This is done so you can inline some elements, such as
668: the <date> element, right between two messages, giving the appearence that
669: the <date> element appears inline. (Note the elements can not be embedded
670: within each other.)
671:
672: This is also a good template for creating your own new states, as it has
673: very little code beyond the state template.
674:
675: =cut
676:
677: no strict;
678: @ISA = ("Apache::lonhelper::element");
679: use strict;
680:
681: BEGIN {
682: &Apache::lonhelper::register('Apache::lonhelper::message',
683: ('message'));
684: }
685:
686: sub new {
687: my $ref = Apache::lonhelper::element->new();
688: bless($ref);
689: }
690:
691: # CONSTRUCTION: Construct the message element from the XML
692: sub start_message {
693: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
694:
695: if ($target ne 'helper') {
696: return '';
697: }
698:
699: $paramHash->{MESSAGE_TEXT} = &Apache::lonxml::get_all_text('/message',
700: $parser);
701:
702: if (defined($token->[2]{'nextstate'})) {
703: $paramHash->{NEXTSTATE} = $token->[2]{'nextstate'};
704: }
705: return '';
706: }
707:
708: sub end_message {
709: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
710:
711: if ($target ne 'helper') {
712: return '';
713: }
714: Apache::lonhelper::message->new();
715: return '';
716: }
717:
718: sub render {
719: my $self = shift;
720:
721: return $self->{MESSAGE_TEXT};
722: }
723: # If a NEXTSTATE was given, switch to it
724: sub postprocess {
725: my $self = shift;
726: if (defined($self->{NEXTSTATE})) {
727: $helper->changeState($self->{NEXTSTATE});
728: }
729:
730: return 1;
731: }
732: 1;
733:
734: package Apache::lonhelper::choices;
735:
736: =pod
737:
738: =head2 Element: choices
739:
740: Choice states provide a single choice to the user as a text selection box.
741: A "choice" is two pieces of text, one which will be displayed to the user
742: (the "human" value), and one which will be passed back to the program
743: (the "computer" value). For instance, a human may choose from a list of
744: resources on disk by title, while your program wants the file name.
745:
746: <choices> takes an attribute "variable" to control which helper variable
747: the result is stored in.
748:
749: <choices> takes an attribute "multichoice" which, if set to a true
750: value, will allow the user to select multiple choices.
751:
752: B<SUB-TAGS>
753:
754: <choices> can have the following subtags:
755:
756: =over 4
757:
758: =item * <nextstate>state_name</nextstate>: If given, this will cause the
759: choice element to transition to the given state after executing. If
760: this is used, do not pass nextstates to the <choice> tag.
761:
762: =item * <choice />: If the choices are static,
763: this element will allow you to specify them. Each choice
764: contains attribute, "computer", as described above. The
765: content of the tag will be used as the human label.
766: For example,
767: <choice computer='234-12-7312'>Bobby McDormik</choice>.
768:
769: <choice> may optionally contain a 'nextstate' attribute, which
770: will be the state transisitoned to if the choice is made, if
771: the choice is not multichoice.
772:
773: =back
774:
775: To create the choices programmatically, either wrap the choices in
776: <condition> tags (prefered), or use an <exec> block inside the <choice>
777: tag. Store the choices in $state->{CHOICES}, which is a list of list
778: references, where each list has three strings. The first is the human
779: name, the second is the computer name. and the third is the option
780: next state. For example:
781:
782: <exec>
783: for (my $i = 65; $i < 65 + 26; $i++) {
784: push @{$state->{CHOICES}}, [chr($i), $i, 'next'];
785: }
786: </exec>
787:
788: This will allow the user to select from the letters A-Z (in ASCII), while
789: passing the ASCII value back into the helper variables, and the state
790: will in all cases transition to 'next'.
791:
792: You can mix and match methods of creating choices, as long as you always
793: "push" onto the choice list, rather then wiping it out. (You can even
794: remove choices programmatically, but that would probably be bad form.)
795:
796: =cut
797:
798: no strict;
799: @ISA = ("Apache::lonhelper::element");
800: use strict;
801:
802: BEGIN {
803: &Apache::lonhelper::register('Apache::lonhelper::choices',
804: ('choice', 'choices'));
805: }
806:
807: sub new {
808: my $ref = Apache::lonhelper::element->new();
809: bless($ref);
810: }
811:
812: # CONSTRUCTION: Construct the message element from the XML
813: sub start_choices {
814: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
815:
816: if ($target ne 'helper') {
817: return '';
818: }
819:
820: # Need to initialize the choices list, so everything can assume it exists
821: $paramHash->{'variable'} = $token->[2]{'variable'};
822: $helper->declareVar($paramHash->{'variable'});
823: $paramHash->{'multichoice'} = $token->[2]{'multichoice'};
824: $paramHash->{CHOICES} = [];
825: return '';
826: }
827:
828: sub end_choices {
829: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
830:
831: if ($target ne 'helper') {
832: return '';
833: }
834: Apache::lonhelper::choices->new();
835: return '';
836: }
837:
838: sub start_choice {
839: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
840:
841: if ($target ne 'helper') {
842: return '';
843: }
844:
845: my $computer = $token->[2]{'computer'};
846: my $human = &Apache::lonxml::get_all_text('/choice',
847: $parser);
848: my $nextstate = $token->[2]{'nextstate'};
849: push @{$paramHash->{CHOICES}}, [$human, $computer, $nextstate];
850: return '';
851: }
852:
853: sub end_choice {
854: return '';
855: }
856:
857: sub render {
858: # START HERE: Replace this with correct choices code.
859: my $self = shift;
860: my $var = $self->{'variable'};
861: my $buttons = '';
862: my $result = '';
863:
864: if ($self->{'multichoice'}) {
865: $result .= <<SCRIPT;
866: <script>
867: function checkall(value) {
868: for (i=0; i<document.forms.wizform.elements.length; i++) {
869: document.forms.wizform.elements[i].checked=value;
870: }
871: }
872: </script>
873: SCRIPT
874: $buttons = <<BUTTONS;
875: <br />
876: <input type="button" onclick="checkall(true)" value="Select All" />
877: <input type="button" onclick="checkall(false)" value="Unselect All" />
878: <br />
879: BUTTONS
880: }
881:
882: if (defined $self->{ERROR_MSG}) {
883: $result .= '<br /><font color="#FF0000">' . $self->{ERROR_MSG} . '</font><br />';
884: }
885:
886: $result .= $buttons;
887:
888: $result .= "<table>\n\n";
889:
890: my $type = "radio";
891: if ($self->{'multichoice'}) { $type = 'checkbox'; }
892: my $checked = 0;
893: foreach my $choice (@{$self->{CHOICES}}) {
894: $result .= "<tr>\n<td width='20'> </td>\n";
895: $result .= "<td valign='top'><input type='$type' name='$var.forminput'"
896: . "' value='" .
897: HTML::Entities::encode($choice->[1])
898: . "'";
899: if (!$self->{'multichoice'} && !$checked) {
900: $result .= " checked ";
901: $checked = 1;
902: }
903: $result .= "/></td><td> " . $choice->[0] . "</td></tr>\n";
904: }
905: $result .= "</table>\n\n\n";
906: $result .= $buttons;
907:
908: return $result;
909: }
910:
911: # If a NEXTSTATE was given or a nextstate for this choice was
912: # given, switch to it
913: sub postprocess {
914: my $self = shift;
915: my $chosenValue = $ENV{'form.' . $self->{'variable'} . '.forminput'};
916:
917: if (!$chosenValue) {
918: $self->{ERROR_MSG} = "You must choose one or more choices to" .
919: " continue.";
920: return 0;
921: }
922:
923: if ($self->{'multichoice'}) {
924: $self->process_multiple_choices($self->{'variable'}.'.forminput',
925: $self->{'variable'});
926: }
927:
928: if (defined($self->{NEXTSTATE})) {
929: $helper->changeState($self->{NEXTSTATE});
930: }
931:
932: foreach my $choice (@{$self->{CHOICES}}) {
933: if ($choice->[1] eq $chosenValue) {
934: if (defined($choice->[2])) {
935: $helper->changeState($choice->[2]);
936: }
937: }
938: }
939: return 1;
940: }
941: 1;
942:
943: package Apache::lonhelper::date;
944:
945: =pod
946:
947: =head2 Element: date
948:
949: Date elements allow the selection of a date with a drop down list.
950:
951: Date elements can take two attributes:
952:
953: =over 4
954:
955: =item * B<variable>: The name of the variable to store the chosen
956: date in. Required.
957:
958: =item * B<hoursminutes>: If a true value, the date will show hours
959: and minutes, as well as month/day/year. If false or missing,
960: the date will only show the month, day, and year.
961:
962: =back
963:
964: Date elements contain only an option <nextstate> tag to determine
965: the next state.
966:
967: Example:
968:
969: <date variable="DUE_DATE" hoursminutes="1">
970: <nextstate>choose_why</nextstate>
971: </date>
972:
973: =cut
974:
975: no strict;
976: @ISA = ("Apache::lonhelper::element");
977: use strict;
978:
979: use Time::localtime;
980:
981: BEGIN {
982: &Apache::lonhelper::register('Apache::lonhelper::date',
983: ('date'));
984: }
985:
986: # Don't need to override the "new" from element
987: sub new {
988: my $ref = Apache::lonhelper::element->new();
989: bless($ref);
990: }
991:
992: my @months = ("January", "February", "March", "April", "May", "June", "July",
993: "August", "September", "October", "November", "December");
994:
995: # CONSTRUCTION: Construct the message element from the XML
996: sub start_date {
997: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
998:
999: if ($target ne 'helper') {
1000: return '';
1001: }
1002:
1003: $paramHash->{'variable'} = $token->[2]{'variable'};
1004: $helper->declareVar($paramHash->{'variable'});
1005: $paramHash->{'hoursminutes'} = $token->[2]{'hoursminutes'};
1006: }
1007:
1008: sub end_date {
1009: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1010:
1011: if ($target ne 'helper') {
1012: return '';
1013: }
1014: Apache::lonhelper::date->new();
1015: return '';
1016: }
1017:
1018: sub render {
1019: my $self = shift;
1020: my $result = "";
1021: my $var = $self->{'variable'};
1022:
1023: my $date;
1024:
1025: # Default date: The current hour.
1026: $date = localtime();
1027: $date->min(0);
1028:
1029: if (defined $self->{ERROR_MSG}) {
1030: $result .= '<font color="#FF0000">' . $self->{ERROR_MSG} . '</font><br /><br />';
1031: }
1032:
1033: # Month
1034: my $i;
1035: $result .= "<select name='${var}month'>\n";
1036: for ($i = 0; $i < 12; $i++) {
1037: if ($i == $date->mon) {
1038: $result .= "<option value='$i' selected>";
1039: } else {
1040: $result .= "<option value='$i'>";
1041: }
1042: $result .= $months[$i] . "</option>\n";
1043: }
1044: $result .= "</select>\n";
1045:
1046: # Day
1047: $result .= "<select name='${var}day'>\n";
1048: for ($i = 1; $i < 32; $i++) {
1049: if ($i == $date->mday) {
1050: $result .= '<option selected>';
1051: } else {
1052: $result .= '<option>';
1053: }
1054: $result .= "$i</option>\n";
1055: }
1056: $result .= "</select>,\n";
1057:
1058: # Year
1059: $result .= "<select name='${var}year'>\n";
1060: for ($i = 2000; $i < 2030; $i++) { # update this after 64-bit dates
1061: if ($date->year + 1900 == $i) {
1062: $result .= "<option selected>";
1063: } else {
1064: $result .= "<option>";
1065: }
1066: $result .= "$i</option>\n";
1067: }
1068: $result .= "</select>,\n";
1069:
1070: # Display Hours and Minutes if they are called for
1071: if ($self->{'hoursminutes'}) {
1072: # Build hour
1073: $result .= "<select name='${var}hour'>\n";
1074: $result .= "<option " . ($date->hour == 0 ? 'selected ':'') .
1075: " value='0'>midnight</option>\n";
1076: for ($i = 1; $i < 12; $i++) {
1077: if ($date->hour == $i) {
1078: $result .= "<option selected value='$i'>$i a.m.</option>\n";
1079: } else {
1080: $result .= "<option value='$i'>$i a.m</option>\n";
1081: }
1082: }
1083: $result .= "<option " . ($date->hour == 12 ? 'selected ':'') .
1084: " value='12'>noon</option>\n";
1085: for ($i = 13; $i < 24; $i++) {
1086: my $printedHour = $i - 12;
1087: if ($date->hour == $i) {
1088: $result .= "<option selected value='$i'>$printedHour p.m.</option>\n";
1089: } else {
1090: $result .= "<option value='$i'>$printedHour p.m.</option>\n";
1091: }
1092: }
1093:
1094: $result .= "</select> :\n";
1095:
1096: $result .= "<select name='${var}minute'>\n";
1097: for ($i = 0; $i < 60; $i++) {
1098: my $printedMinute = $i;
1099: if ($i < 10) {
1100: $printedMinute = "0" . $printedMinute;
1101: }
1102: if ($date->min == $i) {
1103: $result .= "<option selected>";
1104: } else {
1105: $result .= "<option>";
1106: }
1107: $result .= "$printedMinute</option>\n";
1108: }
1109: $result .= "</select>\n";
1110: }
1111:
1112: return $result;
1113:
1114: }
1115: # If a NEXTSTATE was given, switch to it
1116: sub postprocess {
1117: my $self = shift;
1118: my $var = $self->{'variable'};
1119: my $month = $ENV{'form.' . $var . 'month'};
1120: my $day = $ENV{'form.' . $var . 'day'};
1121: my $year = $ENV{'form.' . $var . 'year'};
1122: my $min = 0;
1123: my $hour = 0;
1124: if ($self->{'hoursminutes'}) {
1125: $min = $ENV{'form.' . $var . 'minute'};
1126: $hour = $ENV{'form.' . $var . 'hour'};
1127: }
1128:
1129: my $chosenDate = Time::Local::timelocal(0, $min, $hour, $day, $month, $year);
1130: # Check to make sure that the date was not automatically co-erced into a
1131: # valid date, as we want to flag that as an error
1132: # This happens for "Feb. 31", for instance, which is coerced to March 2 or
1133: # 3, depending on if it's a leapyear
1134: my $checkDate = localtime($chosenDate);
1135:
1136: if ($checkDate->mon != $month || $checkDate->mday != $day ||
1137: $checkDate->year + 1900 != $year) {
1138: $self->{ERROR_MSG} = "Can't use " . $months[$month] . " $day, $year as a "
1139: . "date because it doesn't exist. Please enter a valid date.";
1140: return 0;
1141: }
1142:
1143: $helper->{VARS}->{$var} = $chosenDate;
1144:
1145: if (defined($self->{NEXTSTATE})) {
1146: $helper->changeState($self->{NEXTSTATE});
1147: }
1148:
1149: return 1;
1150: }
1151: 1;
1152:
1153: package Apache::lonhelper::resource;
1154:
1155: =pod
1156:
1157: =head2 Element: resource
1158:
1159: <resource> elements allow the user to select one or multiple resources
1160: from the current course. You can filter out which resources they can view,
1161: and filter out which resources they can select. The course will always
1162: be displayed fully expanded, because of the difficulty of maintaining
1163: selections across folder openings and closings. If this is fixed, then
1164: the user can manipulate the folders.
1165:
1166: <resource> takes the standard variable attribute to control what helper
1167: variable stores the results. It also takes a "multichoice" attribute,
1168: which controls whether the user can select more then one resource.
1169:
1170: B<SUB-TAGS>
1171:
1172: =over 4
1173:
1174: =item * <filterfunc>: If you want to filter what resources are displayed
1175: to the user, use a filter func. The <filterfunc> tag should contain
1176: Perl code that when wrapped with "sub { my $res = shift; " and "}" is
1177: a function that returns true if the resource should be displayed,
1178: and false if it should be skipped. $res is a resource object.
1179: (See Apache::lonnavmaps documentation for information about the
1180: resource object.)
1181:
1182: =item * <choicefunc>: Same as <filterfunc>, except that controls whether
1183: the given resource can be chosen. (It is almost always a good idea to
1184: show the user the folders, for instance, but you do not always want to
1185: let the user select them.)
1186:
1187: =item * <nextstate>: Standard nextstate behavior.
1188:
1189: =item * <valuefunc>: This function controls what is returned by the resource
1190: when the user selects it. Like filterfunc and choicefunc, it should be
1191: a function fragment that when wrapped by "sub { my $res = shift; " and
1192: "}" returns a string representing what you want to have as the value. By
1193: default, the value will be the resource ID of the object ($res->{ID}).
1194:
1195: =back
1196:
1197: =cut
1198:
1199: no strict;
1200: @ISA = ("Apache::lonhelper::element");
1201: use strict;
1202:
1203: BEGIN {
1204: &Apache::lonhelper::register('Apache::lonhelper::resource',
1205: ('resource', 'filterfunc',
1206: 'choicefunc', 'valuefunc'));
1207: }
1208:
1209: sub new {
1210: my $ref = Apache::lonhelper::element->new();
1211: bless($ref);
1212: }
1213:
1214: # CONSTRUCTION: Construct the message element from the XML
1215: sub start_resource {
1216: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1217:
1218: if ($target ne 'helper') {
1219: return '';
1220: }
1221:
1222: $paramHash->{'variable'} = $token->[2]{'variable'};
1223: $helper->declareVar($paramHash->{'variable'});
1224: return '';
1225: }
1226:
1227: sub end_resource {
1228: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1229:
1230: if ($target ne 'helper') {
1231: return '';
1232: }
1233: if (!defined($paramHash->{FILTER_FUNC})) {
1234: $paramHash->{FILTER_FUNC} = sub {return 1;};
1235: }
1236: if (!defined($paramHash->{CHOICE_FUNC})) {
1237: $paramHash->{CHOICE_FUNC} = sub {return 1;};
1238: }
1239: if (!defined($paramHash->{VALUE_FUNC})) {
1240: $paramHash->{VALUE_FUNC} = sub {my $res = shift; return $res->{ID}; };
1241: }
1242: Apache::lonhelper::resource->new();
1243: return '';
1244: }
1245:
1246: sub start_filterfunc {
1247: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1248:
1249: if ($target ne 'helper') {
1250: return '';
1251: }
1252:
1253: my $contents = Apache::lonxml::get_all_text('/filterfunc',
1254: $parser);
1255: $contents = 'sub { my $res = shift; ' . $contents . '}';
1256: $paramHash->{FILTER_FUNC} = eval $contents;
1257: }
1258:
1259: sub end_filterfunc { return ''; }
1260:
1261: sub start_choicefunc {
1262: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1263:
1264: if ($target ne 'helper') {
1265: return '';
1266: }
1267:
1268: my $contents = Apache::lonxml::get_all_text('/choicefunc',
1269: $parser);
1270: $contents = 'sub { my $res = shift; ' . $contents . '}';
1271: $paramHash->{CHOICE_FUNC} = eval $contents;
1272: }
1273:
1274: sub end_choicefunc { return ''; }
1275:
1276: sub start_valuefunc {
1277: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1278:
1279: if ($target ne 'helper') {
1280: return '';
1281: }
1282:
1283: my $contents = Apache::lonxml::get_all_text('/valuefunc',
1284: $parser);
1285: $contents = 'sub { my $res = shift; ' . $contents . '}';
1286: $paramHash->{VALUE_FUNC} = eval $contents;
1287: }
1288:
1289: sub end_valuefunc { return ''; }
1290:
1291: # A note, in case I don't get to this before I leave.
1292: # If someone complains about the "Back" button returning them
1293: # to the previous folder state, instead of returning them to
1294: # the previous helper state, the *correct* answer is for the helper
1295: # to keep track of how many times the user has manipulated the folders,
1296: # and feed that to the history.go() call in the helper rendering routines.
1297: # If done correctly, the helper itself can keep track of how many times
1298: # it renders the same states, so it doesn't go in just this state, and
1299: # you can lean on the browser back button to make sure it all chains
1300: # correctly.
1301: # Right now, though, I'm just forcing all folders open.
1302:
1303: sub render {
1304: my $self = shift;
1305: my $result = "";
1306: my $var = $self->{'variable'};
1307: my $curVal = $helper->{VARS}->{$var};
1308:
1309: if (defined $self->{ERROR_MSG}) {
1310: $result .= '<font color="#FF0000">' . $self->{ERROR_MSG} . '</font><br /><br />';
1311: }
1312:
1313: my $filterFunc = $self->{FILTER_FUNC};
1314: my $choiceFunc = $self->{CHOICE_FUNC};
1315: my $valueFunc = $self->{VALUE_FUNC};
1316:
1317: # Create the composite function that renders the column on the nav map
1318: # have to admit any language that lets me do this can't be all bad
1319: # - Jeremy (Pythonista) ;-)
1320: my $checked = 0;
1321: my $renderColFunc = sub {
1322: my ($resource, $part, $params) = @_;
1323:
1324: if (!&$choiceFunc($resource)) {
1325: return '<td> </td>';
1326: } else {
1327: my $col = "<td><input type='radio' name='${var}.forminput' ";
1328: if (!$checked) {
1329: $col .= "checked ";
1330: $checked = 1;
1331: }
1332: $col .= "value='" .
1333: HTML::Entities::encode(&$valueFunc($resource))
1334: . "' /></td>";
1335: return $col;
1336: }
1337: };
1338:
1339: $ENV{'form.condition'} = 1;
1340: $result .=
1341: &Apache::lonnavmaps::render( { 'cols' => [$renderColFunc,
1342: Apache::lonnavmaps::resource()],
1343: 'showParts' => 0,
1344: 'url' => $helper->{URL},
1345: 'filterFunc' => $filterFunc,
1346: 'resource_no_folder_link' => 1 }
1347: );
1348:
1349: return $result;
1350: }
1351:
1352: sub postprocess {
1353: my $self = shift;
1354: if (defined($self->{NEXTSTATE})) {
1355: $helper->changeState($self->{NEXTSTATE});
1356: }
1357:
1358: return 1;
1359: }
1360:
1361: 1;
1362:
1363: package Apache::lonhelper::student;
1364:
1365: =pod
1366:
1367: =head2 Element: student
1368:
1369: Student elements display a choice of students enrolled in the current
1370: course. Currently it is primitive; this is expected to evolve later.
1371:
1372: Student elements take two attributes: "variable", which means what
1373: it usually does, and "multichoice", which if true allows the user
1374: to select multiple students.
1375:
1376: =cut
1377:
1378: no strict;
1379: @ISA = ("Apache::lonhelper::element");
1380: use strict;
1381:
1382:
1383:
1384: BEGIN {
1385: &Apache::lonhelper::register('Apache::lonhelper::student',
1386: ('student'));
1387: }
1388:
1389: sub new {
1390: my $ref = Apache::lonhelper::element->new();
1391: bless($ref);
1392: }
1393:
1394: sub start_student {
1395: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1396:
1397: if ($target ne 'helper') {
1398: return '';
1399: }
1400:
1401: $paramHash->{'variable'} = $token->[2]{'variable'};
1402: $helper->declareVar($paramHash->{'variable'});
1403: $paramHash->{'multichoice'} = $token->[2]{'multichoice'};
1404: }
1405:
1406: sub end_student {
1407: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1408:
1409: if ($target ne 'helper') {
1410: return '';
1411: }
1412: Apache::lonhelper::student->new();
1413: }
1414:
1415: sub render {
1416: my $self = shift;
1417: my $result = '';
1418: my $buttons = '';
1419:
1420: if ($self->{'multichoice'}) {
1421: $result = <<SCRIPT;
1422: <script>
1423: function checkall(value) {
1424: for (i=0; i<document.forms.wizform.elements.length; i++) {
1425: document.forms.wizform.elements[i].checked=value;
1426: }
1427: }
1428: </script>
1429: SCRIPT
1430: $buttons = <<BUTTONS;
1431: <br />
1432: <input type="button" onclick="checkall(true)" value="Select All" />
1433: <input type="button" onclick="checkall(false)" value="Unselect All" />
1434: <br />
1435: BUTTONS
1436: }
1437:
1438: if (defined $self->{ERROR_MSG}) {
1439: $result .= '<font color="#FF0000">' . $self->{ERROR_MSG} . '</font><br /><br />';
1440: }
1441:
1442: # Load up the students
1443: my $choices = &Apache::loncoursedata::get_classlist();
1444:
1445: my @keys = keys %{$choices};
1446:
1447: # Constants
1448: my $section = Apache::loncoursedata::CL_SECTION();
1449: my $fullname = Apache::loncoursedata::CL_FULLNAME();
1450:
1451: # Sort by: Section, name
1452: @keys = sort {
1453: if ($choices->{$a}->[$section] ne $choices->{$b}->[$section]) {
1454: return $choices->{$a}->[$section] cmp $choices->{$b}->[$section];
1455: }
1456: return $choices->{$a}->[$fullname] cmp $choices->{$b}->[$fullname];
1457: } @keys;
1458:
1459: my $type = 'radio';
1460: if ($self->{'multichoice'}) { $type = 'checkbox'; }
1461: $result .= "<table cellspacing='2' cellpadding='2' border='0'>\n";
1462: $result .= "<tr><td></td><td align='center'><b>Student Name</b></td>".
1463: "<td align='center'><b>Section</b></td></tr>";
1464:
1465: my $checked = 0;
1466: foreach (@keys) {
1467: $result .= "<tr><td><input type='$type' name='" .
1468: $self->{'variable'} . '.forminput' . "'";
1469:
1470: if (!$self->{'multichoice'} && !$checked) {
1471: $result .= " checked ";
1472: $checked = 1;
1473: }
1474: $result .=
1475: " value='" . HTML::Entities::encode($_)
1476: . "' /></td><td>"
1477: . HTML::Entities::encode($choices->{$_}->[$fullname])
1478: . "</td><td align='center'>"
1479: . HTML::Entities::encode($choices->{$_}->[$section])
1480: . "</td></tr>\n";
1481: }
1482:
1483: $result .= "</table>\n\n";
1484: $result .= $buttons;
1485:
1486: return $result;
1487: }
1488:
1489: sub postprocess {
1490: my $self = shift;
1491:
1492: my $result = $ENV{'form.' . $self->{'variable'} . '.forminput'};
1493: if (!$result) {
1494: $self->{ERROR_MSG} = 'You must choose at least one student '.
1495: 'to continue.';
1496: return 0;
1497: }
1498:
1499: if ($self->{'multichoice'}) {
1500: $self->process_multiple_choices($self->{'variable'}.'.forminput',
1501: $self->{'variable'});
1502: }
1503: if (defined($self->{NEXTSTATE})) {
1504: $helper->changeState($self->{NEXTSTATE});
1505: }
1506:
1507: return 1;
1508: }
1509:
1510: 1;
1511:
1512: package Apache::lonhelper::files;
1513:
1514: =pod
1515:
1516: =head2 Element: files
1517:
1518: files allows the users to choose files from a given directory on the
1519: server. It is always multichoice and stores the result as a triple-pipe
1520: delimited entry in the helper variables.
1521:
1522: Since it is extremely unlikely that you can actually code a constant
1523: representing the directory you wish to allow the user to search, <files>
1524: takes a subroutine that returns the name of the directory you wish to
1525: have the user browse.
1526:
1527: files accepts the attribute "variable" to control where the files chosen
1528: are put. It accepts the attribute "multichoice" as the other attribute,
1529: defaulting to false, which if true will allow the user to select more
1530: then one choice.
1531:
1532: <files> accepts three subtags. One is the "nextstate" sub-tag that works
1533: as it does with the other tags. Another is a <filechoice> sub tag that
1534: is Perl code that, when surrounded by "sub {" and "}" will return a
1535: string representing what directory on the server to allow the user to
1536: choose files from. Finally, the <filefilter> subtag should contain Perl
1537: code that when surrounded by "sub { my $filename = shift; " and "}",
1538: returns a true value if the user can pick that file, or false otherwise.
1539: The filename passed to the function will be just the name of the file,
1540: with no path info.
1541:
1542: =cut
1543:
1544: no strict;
1545: @ISA = ("Apache::lonhelper::element");
1546: use strict;
1547:
1548: BEGIN {
1549: &Apache::lonhelper::register('Apache::lonhelper::files',
1550: ('files', 'filechoice', 'filefilter'));
1551: }
1552:
1553: sub new {
1554: my $ref = Apache::lonhelper::element->new();
1555: bless($ref);
1556: }
1557:
1558: sub start_files {
1559: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1560:
1561: if ($target ne 'helper') {
1562: return '';
1563: }
1564: $paramHash->{'variable'} = $token->[2]{'variable'};
1565: $helper->declareVar($paramHash->{'variable'});
1566: $paramHash->{'multichoice'} = $token->[2]{'multichoice'};
1567: }
1568:
1569: sub end_files {
1570: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1571:
1572: if ($target ne 'helper') {
1573: return '';
1574: }
1575: if (!defined($paramHash->{FILTER_FUNC})) {
1576: $paramHash->{FILTER_FUNC} = sub { return 1; };
1577: }
1578: Apache::lonhelper::files->new();
1579: }
1580:
1581: sub start_filechoice {
1582: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1583:
1584: if ($target ne 'helper') {
1585: return '';
1586: }
1587: $paramHash->{'filechoice'} = Apache::lonxml::get_all_text('/filechoice',
1588: $parser);
1589: }
1590:
1591: sub end_filechoice { return ''; }
1592:
1593: sub start_filefilter {
1594: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1595:
1596: if ($target ne 'helper') {
1597: return '';
1598: }
1599:
1600: my $contents = Apache::lonxml::get_all_text('/filefilter',
1601: $parser);
1602: $contents = 'sub { my $filename = shift; ' . $contents . '}';
1603: $paramHash->{FILTER_FUNC} = eval $contents;
1604: }
1605:
1606: sub end_filefilter { return ''; }
1607:
1608: sub render {
1609: my $self = shift;
1610: my $result = '';
1611: my $var = $self->{'variable'};
1612:
1613: my $subdirFunc = eval('sub {' . $self->{'filechoice'} . '}');
1614: die 'Error in resource filter code for variable ' .
1615: {'variable'} . ', Perl said:' . $@ if $@;
1616:
1617: my $subdir = &$subdirFunc();
1618:
1619: my $filterFunc = $self->{FILTER_FUNC};
1620: my $buttons = '';
1621:
1622: if ($self->{'multichoice'}) {
1623: $result = <<SCRIPT;
1624: <script>
1625: function checkall(value) {
1626: for (i=0; i<document.forms.wizform.elements.length; i++) {
1627: ele = document.forms.wizform.elements[i];
1628: if (ele.type == "checkbox") {
1629: document.forms.wizform.elements[i].checked=value;
1630: }
1631: }
1632: }
1633: </script>
1634: SCRIPT
1635: my $buttons = <<BUTTONS;
1636: <br />
1637: <input type="button" onclick="checkall(true)" value="Select All" />
1638: <input type="button" onclick="checkall(false)" value="Unselect All" />
1639: <br />
1640: BUTTONS
1641: }
1642:
1643: # Get the list of files in this directory.
1644: my @fileList;
1645:
1646: # If the subdirectory is in local CSTR space
1647: if ($subdir =~ m|/home/([^/]+)/public_html|) {
1648: my $user = $1;
1649: my $domain = $Apache::lonnet::perlvar{'lonDefDomain'};
1650: @fileList = &Apache::lonnet::dirlist($subdir, $domain, $user, '');
1651: } else {
1652: # local library server resource space
1653: @fileList = &Apache::lonnet::dirlist($subdir, $ENV{'user.domain'}, $ENV{'user.name'}, '');
1654: }
1655:
1656: $result .= $buttons;
1657:
1658: if (defined $self->{ERROR_MSG}) {
1659: $result .= '<br /><font color="#FF0000">' . $self->{ERROR_MSG} . '</font><br /><br />';
1660: }
1661:
1662: $result .= '<table border="0" cellpadding="1" cellspacing="1">';
1663:
1664: # Keeps track if there are no choices, prints appropriate error
1665: # if there are none.
1666: my $choices = 0;
1667: my $type = 'radio';
1668: if ($self->{'multichoice'}) {
1669: $type = 'checkbox';
1670: }
1671: # Print each legitimate file choice.
1672: for my $file (@fileList) {
1673: $file = (split(/&/, $file))[0];
1674: if ($file eq '.' || $file eq '..') {
1675: next;
1676: }
1677: my $fileName = $subdir .'/'. $file;
1678: if (&$filterFunc($file)) {
1679: $result .= '<tr><td align="right">' .
1680: "<input type='$type' name='" . $var
1681: . ".forminput' value='" . HTML::Entities::encode($fileName) .
1682: "'";
1683: if (!$self->{'multichoice'} && $choices == 0) {
1684: $result .= ' checked';
1685: }
1686: $result .= "/></td><td>" . $file . "</td></tr>\n";
1687: $choices++;
1688: }
1689: }
1690:
1691: $result .= "</table>\n";
1692:
1693: if (!$choices) {
1694: $result .= '<font color="#FF0000">There are no files available to select in this directory. Please go back and select another option.</font><br /><br />';
1695: }
1696:
1697: $result .= $buttons;
1698:
1699: return $result;
1700: }
1701:
1702: sub postprocess {
1703: my $self = shift;
1704: my $result = $ENV{'form.' . $self->{'variable'} . '.forminput'};
1705: if (!$result) {
1706: $self->{ERROR_MSG} = 'You must choose at least one file '.
1707: 'to continue.';
1708: return 0;
1709: }
1710:
1711: if ($self->{'multichoice'}) {
1712: $self->process_multiple_choices($self->{'variable'}.'.forminput',
1713: $self->{'variable'});
1714: }
1715: if (defined($self->{NEXTSTATE})) {
1716: $helper->changeState($self->{NEXTSTATE});
1717: }
1718:
1719: return 1;
1720: }
1721:
1722: 1;
1723:
1724: package Apache::lonhelper::section;
1725:
1726: =pod
1727:
1728: =head2 Element: section
1729:
1730: <section> allows the user to choose one or more sections from the current
1731: course.
1732:
1733: It takes the standard attributes "variable", "multichoice", and
1734: "nextstate", meaning what they do for most other elements.
1735:
1736: =cut
1737:
1738: no strict;
1739: @ISA = ("Apache::lonhelper::choices");
1740: use strict;
1741:
1742: BEGIN {
1743: &Apache::lonhelper::register('Apache::lonhelper::section',
1744: ('section'));
1745: }
1746:
1747: sub new {
1748: my $ref = Apache::lonhelper::choices->new();
1749: bless($ref);
1750: }
1751:
1752: sub start_section {
1753: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1754:
1755: $paramHash->{CHOICES} = [];
1756:
1757: if ($target ne 'helper') {
1758: return '';
1759: }
1760: $paramHash->{'variable'} = $token->[2]{'variable'};
1761: $helper->declareVar($paramHash->{'variable'});
1762: $paramHash->{'multichoice'} = $token->[2]{'multichoice'};
1763: if (defined($token->[2]{'nextstate'})) {
1764: $paramHash->{'nextstate'} = $token->[2]{'nextstate'};
1765: }
1766:
1767: # Populate the CHOICES element
1768: my %choices;
1769:
1770: my $section = Apache::loncoursedata::CL_SECTION();
1771: my $classlist = Apache::loncoursedata::get_classlist();
1772: foreach (keys %$classlist) {
1773: my $sectionName = $classlist->{$_}->[$section];
1774: if (!$sectionName) {
1775: $choices{"No section assigned"} = "";
1776: } else {
1777: $choices{$sectionName} = $sectionName;
1778: }
1779: }
1780:
1781: for my $sectionName (sort(keys(%choices))) {
1782: push @{$paramHash->{CHOICES}}, [$sectionName, $sectionName];
1783: }
1784:
1785: }
1786:
1787: sub end_section { return ''; }
1788:
1789: 1;
1790:
1791: package Apache::lonhelper::general;
1792:
1793: =pod
1794:
1795: =head2 General-purpose tag: <exec>
1796:
1797: The contents of the exec tag are executed as Perl code, not inside a
1798: safe space, so the full range of $ENV and such is available. The code
1799: will be executed as a subroutine wrapped with the following code:
1800:
1801: "sub { my $helper = shift; my $state = shift;" and
1802:
1803: "}"
1804:
1805: The return value is ignored.
1806:
1807: $helper is the helper object. Feel free to add methods to the helper
1808: object to support whatever manipulation you may need to do (for instance,
1809: overriding the form location if the state is the final state; see
1810: lonparm.helper for an example).
1811:
1812: $state is the $paramHash that has currently been generated and may
1813: be manipulated by the code in exec. Note that the $state is not yet
1814: an actual state B<object>, it is just a hash, so do not expect to
1815: be able to call methods on it.
1816:
1817: =cut
1818:
1819: BEGIN {
1820: &Apache::lonhelper::register('Apache::lonhelper::general',
1821: 'exec', 'condition', 'clause',
1822: 'eval');
1823: }
1824:
1825: sub start_exec {
1826: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1827:
1828: if ($target ne 'helper') {
1829: return '';
1830: }
1831:
1832: my $code = &Apache::lonxml::get_all_text('/exec', $parser);
1833:
1834: $code = eval ('sub { my $helper = shift; my $state = shift; ' .
1835: $code . "}");
1836: die 'Error in <exec>, Perl said: '. $@ if $@;
1837: &$code($helper, $paramHash);
1838: }
1839:
1840: sub end_exec { return ''; }
1841:
1842: =pod
1843:
1844: =head2 General-purpose tag: <condition>
1845:
1846: The <condition> tag allows you to mask out parts of the helper code
1847: depending on some programatically determined condition. The condition
1848: tag contains a tag <clause> which contains perl code that when wrapped
1849: with "sub { my $helper = shift; my $state = shift; " and "}", returns
1850: a true value if the XML in the condition should be evaluated as a normal
1851: part of the helper, or false if it should be completely discarded.
1852:
1853: The <clause> tag must be the first sub-tag of the <condition> tag or
1854: it will not work as expected.
1855:
1856: =cut
1857:
1858: # The condition tag just functions as a marker, it doesn't have
1859: # to "do" anything. Technically it doesn't even have to be registered
1860: # with the lonxml code, but I leave this here to be explicit about it.
1861: sub start_condition { return ''; }
1862: sub end_condition { return ''; }
1863:
1864: sub start_clause {
1865: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1866:
1867: if ($target ne 'helper') {
1868: return '';
1869: }
1870:
1871: my $clause = Apache::lonxml::get_all_text('/clause', $parser);
1872: $clause = eval('sub { my $helper = shift; my $state = shift; '
1873: . $clause . '}');
1874: die 'Error in clause of condition, Perl said: ' . $@ if $@;
1875: if (!&$clause($helper, $paramHash)) {
1876: # Discard all text until the /condition.
1877: &Apache::lonxml::get_all_text('/condition', $parser);
1878: }
1879: }
1880:
1881: sub end_clause { return ''; }
1882:
1883: =pod
1884:
1885: =head2 General-purpose tag: <eval>
1886:
1887: The <eval> tag will be evaluated as a subroutine call passed in the
1888: current helper object and state hash as described in <condition> above,
1889: but is expected to return a string to be printed directly to the
1890: screen. This is useful for dynamically generating messages.
1891:
1892: =cut
1893:
1894: # This is basically a type of message.
1895: # Programmatically setting $paramHash->{NEXTSTATE} would work, though
1896: # it's probably bad form.
1897:
1898: sub start_eval {
1899: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1900:
1901: if ($target ne 'helper') {
1902: return '';
1903: }
1904:
1905: my $program = Apache::lonxml::get_all_text('/eval', $parser);
1906: $program = eval('sub { my $helper = shift; my $state = shift; '
1907: . $program . '}');
1908: die 'Error in eval code, Perl said: ' . $@ if $@;
1909: $paramHash->{MESSAGE_TEXT} = &$program($helper, $paramHash);
1910: }
1911:
1912: sub end_eval {
1913: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1914:
1915: if ($target ne 'helper') {
1916: return '';
1917: }
1918:
1919: Apache::lonhelper::message->new();
1920: }
1921:
1922:
1923:
1924: 1;
1925:
1926: __END__
1927:
FreeBSD-CVSweb <freebsd-cvsweb@FreeBSD.org>
![[BACK]](/icons/back.gif){kind=icon}
Return to lonhelper.pm CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [LON-CAPA] / loncom / interface