Annotation of loncom/interface/lonhelper.pm, revision 1.7
1.1 bowersj2 1: # The LearningOnline Network with CAPA
2: # .helper XML handler to implement the LON-CAPA helper
3: #
1.6 bowersj2 4: # $Id: lonhelper.pm,v 1.5 2003/04/10 18:02:09 bowersj2 Exp $
1.1 bowersj2 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:
1.5 bowersj2 33: # FIXME: Change register calls to register with the helper.
34: # Then have the helper reg and unreg the tags.
35: # This removes my concerns about breaking other code.
36:
1.3 bowersj2 37: =pod
38:
39: =head1 lonhelper - HTML Helper framework for LON-CAPA
40:
41: Helpers, often known as "wizards", are well-established UI widgets that users
42: feel comfortable with. It can take a complicated multidimensional problem the
43: user has and turn it into a series of bite-sized one-dimensional questions.
44:
45: For developers, helpers provide an easy way to bundle little bits of functionality
46: for the user, without having to write the tedious state-maintenence code.
47:
48: Helpers are defined as XML documents, placed in the /home/httpd/html/adm/helpers
49: directory and having the .helper file extension. For examples, see that directory.
50:
51: All classes are in the Apache::lonhelper namespace.
52:
53: =head2 lonhelper XML file format
54:
55: A helper consists of a top-level <helper> tag which contains a series of states.
56: Each state contains one or more state elements, which are what the user sees, like
57: messages, resource selections, or date queries.
58:
59: The helper tag is required to have one attribute, "title", which is the name
60: of the helper itself, such as "Parameter helper".
61:
62: =head2 State tags
63:
64: State tags are required to have an attribute "name", which is the symbolic
1.7 ! bowersj2 65: name of the state and will not be directly seen by the user. The helper is
! 66: required to have one state named "START", which is the state the helper
1.5 bowersj2 67: will start with. By convention, this state should clearly describe what
1.3 bowersj2 68: the helper will do for the user, and may also include the first information
69: entry the user needs to do for the helper.
70:
71: State tags are also required to have an attribute "title", which is the
72: human name of the state, and will be displayed as the header on top of
73: the screen for the user.
74:
75: =head2 Example Helper Skeleton
76:
77: An example of the tags so far:
78:
79: <helper title="Example Helper">
80: <state name="START" title="Demonstrating the Example Helper">
81: <!-- notice this is the START state the wizard requires -->
82: </state>
83: <state name="GET_NAME" title="Enter Student Name">
84: </state>
85: </helper>
86:
87: Of course this does nothing. In order for the wizard to do something, it is
88: necessary to put actual elements into the wizard. Documentation for each
89: of these elements follows.
90:
91: =cut
92:
1.1 bowersj2 93: package Apache::lonhelper;
1.2 bowersj2 94: use Apache::Constants qw(:common);
95: use Apache::File;
1.3 bowersj2 96: use Apache::lonxml;
1.2 bowersj2 97:
1.7 ! bowersj2 98: # Register all the tags with the helper, so the helper can
! 99: # push and pop them
! 100:
! 101: my @helperTags;
! 102:
! 103: sub register {
! 104: my ($namespace, @tags) = @_;
! 105:
! 106: for my $tag (@tags) {
! 107: push @helperTags, [$namespace, $tag];
! 108: }
! 109: }
! 110:
1.2 bowersj2 111: BEGIN {
1.7 ! bowersj2 112: Apache::lonxml::register('Apache::lonhelper',
! 113: ('helper'));
! 114: register('Apache::lonhelper', ('state'));
1.2 bowersj2 115: }
116:
1.7 ! bowersj2 117: # Since all helpers are only three levels deep (helper tag, state tag,
1.3 bowersj2 118: # substate type), it's easier and more readble to explicitly track
119: # those three things directly, rather then futz with the tag stack
120: # every time.
121: my $helper;
122: my $state;
123: my $substate;
1.4 bowersj2 124: # To collect parameters, the contents of the subtags are collected
125: # into this paramHash, then passed to the element object when the
126: # end of the element tag is located.
127: my $paramHash;
1.2 bowersj2 128:
129: sub handler {
1.3 bowersj2 130: my $r = shift;
1.2 bowersj2 131: $ENV{'request.uri'} = $r->uri();
132: my $filename = '/home/httpd/html' . $r->uri();
133: my $fh = Apache::File->new($filename);
134: my $file;
1.3 bowersj2 135: read $fh, $file, 100000000;
136:
137: Apache::loncommon::get_unprocessed_cgi($ENV{QUERY_STRING});
138:
139: # Send header, don't cache this page
140: if ($r->header_only) {
141: if ($ENV{'browser.mathml'}) {
142: $r->content_type('text/xml');
143: } else {
144: $r->content_type('text/html');
145: }
146: $r->send_http_header;
147: return OK;
148: }
149: if ($ENV{'browser.mathml'}) {
150: $r->content_type('text/xml');
151: } else {
152: $r->content_type('text/html');
153: }
154: $r->send_http_header;
155: $r->rflush();
1.2 bowersj2 156:
1.3 bowersj2 157: # Discard result, we just want the objects that get created by the
158: # xml parsing
159: &Apache::lonxml::xmlparse($r, 'helper', $file);
1.2 bowersj2 160:
1.3 bowersj2 161: $r->print($helper->display());
1.7 ! bowersj2 162: return OK;
1.2 bowersj2 163: }
164:
165: sub start_helper {
166: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
167:
168: if ($target ne 'helper') {
169: return '';
170: }
1.7 ! bowersj2 171:
! 172: for my $tagList (@helperTags) {
! 173: Apache::lonxml::register($tagList->[0], $tagList->[1]);
! 174: }
1.2 bowersj2 175:
1.3 bowersj2 176: $helper = Apache::lonhelper::helper->new($token->[2]{'title'});
1.4 bowersj2 177: return '';
1.2 bowersj2 178: }
179:
180: sub end_helper {
181: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
182:
1.3 bowersj2 183: if ($target ne 'helper') {
184: return '';
185: }
1.7 ! bowersj2 186:
! 187: for my $tagList (@helperTags) {
! 188: Apache::lonxml::deregister($tagList->[0], $tagList->[1]);
! 189: }
! 190:
1.4 bowersj2 191: return '';
1.2 bowersj2 192: }
1.1 bowersj2 193:
1.3 bowersj2 194: sub start_state {
195: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
196:
197: if ($target ne 'helper') {
198: return '';
199: }
200:
201: $state = Apache::lonhelper::state->new($token->[2]{'name'},
202: $token->[2]{'title'});
203: return '';
204: }
205:
206: # don't need this, so ignore it
207: sub end_state {
208: return '';
209: }
210:
1.1 bowersj2 211: 1;
212:
1.3 bowersj2 213: package Apache::lonhelper::helper;
214:
215: use Digest::MD5 qw(md5_hex);
216: use HTML::Entities;
217: use Apache::loncommon;
218: use Apache::File;
219:
220: sub new {
221: my $proto = shift;
222: my $class = ref($proto) || $proto;
223: my $self = {};
224:
225: $self->{TITLE} = shift;
226:
227: # If there is a state from the previous form, use that. If there is no
228: # state, use the start state parameter.
229: if (defined $ENV{"form.CURRENT_STATE"})
230: {
231: $self->{STATE} = $ENV{"form.CURRENT_STATE"};
232: }
233: else
234: {
235: $self->{STATE} = "START";
236: }
237:
238: $self->{TOKEN} = $ENV{'form.TOKEN'};
239: # If a token was passed, we load that in. Otherwise, we need to create a
240: # new storage file
241: # Tried to use standard Tie'd hashes, but you can't seem to take a
242: # reference to a tied hash and write to it. I'd call that a wart.
243: if ($self->{TOKEN}) {
244: # Validate the token before trusting it
245: if ($self->{TOKEN} !~ /^[a-f0-9]{32}$/) {
246: # Not legit. Return nothing and let all hell break loose.
247: # User shouldn't be doing that!
248: return undef;
249: }
250:
251: # Get the hash.
252: $self->{FILENAME} = $Apache::lonnet::tmpdir . md5_hex($self->{TOKEN}); # Note the token is not the literal file
253:
254: my $file = Apache::File->new($self->{FILENAME});
255: my $contents = <$file>;
1.5 bowersj2 256:
257: # Now load in the contents
258: for my $value (split (/&/, $contents)) {
259: my ($name, $value) = split(/=/, $value);
260: $value =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C", hex($1))/eg;
261: $self->{VARS}->{$name} = $value;
262: }
263:
1.3 bowersj2 264: $file->close();
265: } else {
266: # Only valid if we're just starting.
267: if ($self->{STATE} ne 'START') {
268: return undef;
269: }
270: # Must create the storage
271: $self->{TOKEN} = md5_hex($ENV{'user.name'} . $ENV{'user.domain'} .
272: time() . rand());
273: $self->{FILENAME} = $Apache::lonnet::tmpdir . md5_hex($self->{TOKEN});
274: }
275:
276: # OK, we now have our persistent storage.
277:
278: if (defined $ENV{"form.RETURN_PAGE"})
279: {
280: $self->{RETURN_PAGE} = $ENV{"form.RETURN_PAGE"};
281: }
282: else
283: {
284: $self->{RETURN_PAGE} = $ENV{REFERER};
285: }
286:
287: $self->{STATES} = {};
288: $self->{DONE} = 0;
289:
290: bless($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:
1.5 bowersj2 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:
1.3 bowersj2 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:
1.5 bowersj2 433: foreach my $key (keys %{$self->{VARS}}) {
434: $result .= "|$key| -> " . $self->{VARS}->{$key} . "<br />";
435: }
436:
1.3 bowersj2 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
1.4 bowersj2 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.
1.3 bowersj2 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:
1.4 bowersj2 490: sub preprocess {
491: my $self = shift;
492: for my $element (@{$self->{ELEMENTS}}) {
493: $element->preprocess();
494: }
495: }
496:
1.6 bowersj2 497: # FIXME: Document that all postprocesses must return a true value or
498: # the state transition will be overridden
1.4 bowersj2 499: sub postprocess {
500: my $self = shift;
1.6 bowersj2 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:
1.4 bowersj2 506: for my $element (@{$self->{ELEMENTS}}) {
1.6 bowersj2 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;
1.4 bowersj2 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
1.5 bowersj2 562: the helper variables, like this:
563:
564: CHOICE_1|||CHOICE_2|||CHOICE_3
1.4 bowersj2 565:
566: =back
567:
568: =cut
569:
1.5 bowersj2 570: BEGIN {
1.7 ! bowersj2 571: &Apache::lonhelper::register('Apache::lonhelper::element',
! 572: ('nextstate'));
1.5 bowersj2 573: }
574:
1.4 bowersj2 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 $self;
591: }
592:
1.5 bowersj2 593: sub start_nextstate {
594: my ($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:
1.4 bowersj2 607: sub preprocess {
608: return 1;
609: }
610:
611: sub postprocess {
612: return 1;
613: }
614:
615: sub render {
616: return '';
617: }
618:
1.3 bowersj2 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) {
1.5 bowersj2 626: # Must extract values from querystring directly, as there
1.3 bowersj2 627: # may be more then one.
628: my @values;
1.5 bowersj2 629: for my $formparam (split (/&/, $ENV{QUERY_STRING})) {
1.3 bowersj2 630: my ($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: }
1.5 bowersj2 638: $helper->{VARS}->{$var} = join('|||', @values);
1.3 bowersj2 639: }
640:
641: return;
642: }
643:
1.4 bowersj2 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
1.5 bowersj2 653: transition directly to the state in the <nextstate> tag. Example:
1.4 bowersj2 654:
655: <message>
1.5 bowersj2 656: <nextstate>GET_NAME</nextstate>
1.4 bowersj2 657: <message_text>This is the <b>message</b> the user will see,
658: <i>HTML allowed</i>.</message_text>
659: </message>
660:
1.5 bowersj2 661: This will display the HTML message and transition to the <nextstate> if
1.7 ! bowersj2 662: given. The HTML will be directly inserted into the helper, so if you don't
1.4 bowersj2 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:
1.5 bowersj2 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:
1.4 bowersj2 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 {
1.7 ! bowersj2 682: &Apache::lonhelper::register('Apache::lonhelper::message',
1.5 bowersj2 683: ('message', 'message_text'));
1.3 bowersj2 684: }
685:
1.5 bowersj2 686: sub new {
687: my $ref = Apache::lonhelper::element->new();
688: bless($ref);
689: }
1.4 bowersj2 690:
691: # CONSTRUCTION: Construct the message element from the XML
692: sub start_message {
693: return '';
1.3 bowersj2 694: }
695:
1.4 bowersj2 696: sub end_message {
697: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
698:
699: if ($target ne 'helper') {
700: return '';
701: }
702: Apache::lonhelper::message->new();
703: return '';
1.3 bowersj2 704: }
705:
1.5 bowersj2 706: sub start_message_text {
1.4 bowersj2 707: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
708:
709: if ($target ne 'helper') {
710: return '';
711: }
1.5 bowersj2 712:
713: $paramHash->{MESSAGE_TEXT} = &Apache::lonxml::get_all_text('/message_text',
714: $parser);
715: }
1.3 bowersj2 716:
1.5 bowersj2 717: sub end_message_text { return 1; }
718:
719: sub render {
720: my $self = shift;
721:
722: return $self->{MESSAGE_TEXT};
723: }
724: # If a NEXTSTATE was given, switch to it
725: sub postprocess {
726: my $self = shift;
727: if (defined($self->{NEXTSTATE})) {
728: $helper->changeState($self->{NEXTSTATE});
729: }
1.6 bowersj2 730:
731: return 1;
1.5 bowersj2 732: }
733: 1;
734:
735: package Apache::lonhelper::choices;
736:
737: =pod
738:
739: =head2 Element: choices
740:
741: Choice states provide a single choice to the user as a text selection box.
742: A "choice" is two pieces of text, one which will be displayed to the user
743: (the "human" value), and one which will be passed back to the program
744: (the "computer" value). For instance, a human may choose from a list of
745: resources on disk by title, while your program wants the file name.
746:
747: <choices> takes an attribute "variable" to control which helper variable
748: the result is stored in.
749:
750: <choices> takes an attribute "multichoice" which, if set to a true
751: value, will allow the user to select multiple choices.
752:
753: B<SUB-TAGS>
754:
755: <choices> can have the following subtags:
756:
757: =over 4
758:
759: =item * <nextstate>state_name</nextstate>: If given, this will cause the
760: choice element to transition to the given state after executing. If
761: this is used, do not pass nextstates to the <choice> tag.
762:
763: =item * <choice />: If the choices are static,
764: this element will allow you to specify them. Each choice
765: contains attribute, "computer", as described above. The
766: content of the tag will be used as the human label.
767: For example,
768: <choice computer='234-12-7312'>Bobby McDormik</choice>.
769:
770: <choice> may optionally contain a 'nextstate' attribute, which
771: will be the state transisitoned to if the choice is made, if
772: the choice is not multichoice.
773:
774: =back
775:
776: To create the choices programmatically, either wrap the choices in
777: <condition> tags (prefered), or use an <exec> block inside the <choice>
778: tag. Store the choices in $state->{CHOICES}, which is a list of list
779: references, where each list has three strings. The first is the human
780: name, the second is the computer name. and the third is the option
781: next state. For example:
782:
783: <exec>
784: for (my $i = 65; $i < 65 + 26; $i++) {
785: push @{$state->{CHOICES}}, [chr($i), $i, 'next'];
786: }
787: </exec>
788:
789: This will allow the user to select from the letters A-Z (in ASCII), while
790: passing the ASCII value back into the helper variables, and the state
791: will in all cases transition to 'next'.
792:
793: You can mix and match methods of creating choices, as long as you always
794: "push" onto the choice list, rather then wiping it out. (You can even
795: remove choices programmatically, but that would probably be bad form.)
796:
797: FIXME: Document and implement <exec> and <condition> in the element package.
798:
799: =cut
800:
801: no strict;
802: @ISA = ("Apache::lonhelper::element");
803: use strict;
804:
805: BEGIN {
1.7 ! bowersj2 806: &Apache::lonhelper::register('Apache::lonhelper::choices',
1.5 bowersj2 807: ('choice', 'choices'));
808: }
809:
810: sub new {
811: my $ref = Apache::lonhelper::element->new();
812: bless($ref);
813: }
814:
815: # CONSTRUCTION: Construct the message element from the XML
816: sub start_choices {
817: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
818:
819: if ($target ne 'helper') {
820: return '';
821: }
822:
823: # Need to initialize the choices list, so everything can assume it exists
824: $paramHash->{'variable'} = $token->[2]{'variable'};
825: $helper->declareVar($paramHash->{'variable'});
826: $paramHash->{'multichoice'} = $token->[2]{'multichoice'};
827: $paramHash->{CHOICES} = [];
828: return '';
829: }
830:
831: sub end_choices {
832: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
833:
834: if ($target ne 'helper') {
835: return '';
836: }
837: Apache::lonhelper::choices->new();
838: return '';
839: }
840:
841: sub start_choice {
842: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
843:
844: if ($target ne 'helper') {
845: return '';
846: }
847:
848: my $computer = $token->[2]{'computer'};
849: my $human = &Apache::lonxml::get_all_text('/choice',
850: $parser);
851: my $nextstate = $token->[2]{'nextstate'};
852: push @{$paramHash->{CHOICES}}, [$human, $computer, $nextstate];
853: return '';
854: }
855:
856: sub end_choice {
857: return '';
858: }
859:
860: sub render {
861: # START HERE: Replace this with correct choices code.
862: my $self = shift;
863: my $var = $self->{'variable'};
864: my $buttons = '';
865: my $result = '';
866:
867: if ($self->{'multichoice'}) {
1.6 bowersj2 868: $result .= <<SCRIPT;
1.5 bowersj2 869: <script>
870: function checkall(value) {
871: for (i=0; i<document.forms.wizform.elements.length; i++) {
872: document.forms.wizform.elements[i].checked=value;
873: }
874: }
875: </script>
876: SCRIPT
877: $buttons = <<BUTTONS;
878: <br />
879: <input type="button" onclick="checkall(true)" value="Select All" />
880: <input type="button" onclick="checkall(false)" value="Unselect All" />
1.6 bowersj2 881: <br />
1.5 bowersj2 882: BUTTONS
883: }
884:
885: if (defined $self->{ERROR_MSG}) {
1.6 bowersj2 886: $result .= '<br /><font color="#FF0000">' . $self->{ERROR_MSG} . '</font><br />';
1.5 bowersj2 887: }
888:
889: $result .= $buttons;
1.6 bowersj2 890:
1.5 bowersj2 891: $result .= "<table>\n\n";
892:
893: my $type = "radio";
894: if ($self->{'multichoice'}) { $type = 'checkbox'; }
895: my $checked = 0;
896: foreach my $choice (@{$self->{CHOICES}}) {
897: $result .= "<tr>\n<td width='20'> </td>\n";
898: $result .= "<td valign='top'><input type='$type' name='$var.forminput'"
899: . "' value='" .
900: HTML::Entities::encode($choice->[1])
901: . "'";
902: if (!$self->{'multichoice'} && !$checked) {
903: $result .= " checked ";
904: $checked = 1;
905: }
906: $result .= "/></td><td> " . $choice->[0] . "</td></tr>\n";
907: }
908: $result .= "</table>\n\n\n";
909: $result .= $buttons;
910:
911: return $result;
912: }
913:
914: # If a NEXTSTATE was given or a nextstate for this choice was
915: # given, switch to it
916: sub postprocess {
917: my $self = shift;
918: my $chosenValue = $ENV{'form.' . $self->{'variable'} . '.forminput'};
919:
1.6 bowersj2 920: if (!$chosenValue) {
921: $self->{ERROR_MSG} = "You must choose one or more choices to" .
922: " continue.";
923: return 0;
924: }
925:
926: if ($self->{'multichoice'}) {
927: $self->process_multiple_choices($self->{'variable'}.'.forminput',
928: $self->{'variable'});
929: }
930:
1.5 bowersj2 931: if (defined($self->{NEXTSTATE})) {
932: $helper->changeState($self->{NEXTSTATE});
933: }
934:
935: foreach my $choice (@{$self->{CHOICES}}) {
936: if ($choice->[1] eq $chosenValue) {
937: if (defined($choice->[2])) {
938: $helper->changeState($choice->[2]);
939: }
940: }
941: }
1.6 bowersj2 942: return 1;
1.5 bowersj2 943: }
944: 1;
945:
946: package Apache::lonhelper::date;
947:
948: =pod
949:
950: =head2 Element: date
951:
952: Date elements allow the selection of a date with a drop down list.
953:
954: Date elements can take two attributes:
955:
956: =over 4
957:
958: =item * B<variable>: The name of the variable to store the chosen
959: date in. Required.
960:
961: =item * B<hoursminutes>: If a true value, the date will show hours
962: and minutes, as well as month/day/year. If false or missing,
963: the date will only show the month, day, and year.
964:
965: =back
966:
967: Date elements contain only an option <nextstate> tag to determine
968: the next state.
969:
970: Example:
971:
972: <date variable="DUE_DATE" hoursminutes="1">
973: <nextstate>choose_why</nextstate>
974: </date>
975:
976: =cut
977:
978: no strict;
979: @ISA = ("Apache::lonhelper::element");
980: use strict;
981:
982: use Time::localtime;
983:
984: BEGIN {
1.7 ! bowersj2 985: &Apache::lonhelper::register('Apache::lonhelper::date',
1.5 bowersj2 986: ('date'));
987: }
988:
989: # Don't need to override the "new" from element
990: sub new {
991: my $ref = Apache::lonhelper::element->new();
992: bless($ref);
993: }
994:
995: my @months = ("January", "February", "March", "April", "May", "June", "July",
996: "August", "September", "October", "November", "December");
997:
998: # CONSTRUCTION: Construct the message element from the XML
999: sub start_date {
1000: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1001:
1002: if ($target ne 'helper') {
1003: return '';
1004: }
1005:
1006: $paramHash->{'variable'} = $token->[2]{'variable'};
1007: $helper->declareVar($paramHash->{'variable'});
1008: $paramHash->{'hoursminutes'} = $token->[2]{'hoursminutes'};
1009: }
1010:
1011: sub end_date {
1012: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1013:
1014: if ($target ne 'helper') {
1015: return '';
1016: }
1017: Apache::lonhelper::date->new();
1018: return '';
1019: }
1020:
1021: sub render {
1022: my $self = shift;
1023: my $result = "";
1024: my $var = $self->{'variable'};
1025:
1026: my $date;
1027:
1028: # Default date: The current hour.
1029: $date = localtime();
1030: $date->min(0);
1031:
1032: if (defined $self->{ERROR_MSG}) {
1033: $result .= '<font color="#FF0000">' . $self->{ERROR_MSG} . '</font><br /><br />';
1034: }
1035:
1036: # Month
1037: my $i;
1038: $result .= "<select name='${var}month'>\n";
1039: for ($i = 0; $i < 12; $i++) {
1040: if ($i == $date->mon) {
1041: $result .= "<option value='$i' selected>";
1042: } else {
1043: $result .= "<option value='$i'>";
1044: }
1045: $result .= $months[$i] . "</option>\n";
1046: }
1047: $result .= "</select>\n";
1048:
1049: # Day
1050: $result .= "<select name='${var}day'>\n";
1051: for ($i = 1; $i < 32; $i++) {
1052: if ($i == $date->mday) {
1053: $result .= '<option selected>';
1054: } else {
1055: $result .= '<option>';
1056: }
1057: $result .= "$i</option>\n";
1058: }
1059: $result .= "</select>,\n";
1060:
1061: # Year
1062: $result .= "<select name='${var}year'>\n";
1063: for ($i = 2000; $i < 2030; $i++) { # update this after 64-bit dates
1064: if ($date->year + 1900 == $i) {
1065: $result .= "<option selected>";
1066: } else {
1067: $result .= "<option>";
1068: }
1069: $result .= "$i</option>\n";
1070: }
1071: $result .= "</select>,\n";
1072:
1073: # Display Hours and Minutes if they are called for
1074: if ($self->{'hoursminutes'}) {
1075: # Build hour
1076: $result .= "<select name='${var}hour'>\n";
1077: $result .= "<option " . ($date->hour == 0 ? 'selected ':'') .
1078: " value='0'>midnight</option>\n";
1079: for ($i = 1; $i < 12; $i++) {
1080: if ($date->hour == $i) {
1081: $result .= "<option selected value='$i'>$i a.m.</option>\n";
1082: } else {
1083: $result .= "<option value='$i'>$i a.m</option>\n";
1084: }
1085: }
1086: $result .= "<option " . ($date->hour == 12 ? 'selected ':'') .
1087: " value='12'>noon</option>\n";
1088: for ($i = 13; $i < 24; $i++) {
1089: my $printedHour = $i - 12;
1090: if ($date->hour == $i) {
1091: $result .= "<option selected value='$i'>$printedHour p.m.</option>\n";
1092: } else {
1093: $result .= "<option value='$i'>$printedHour p.m.</option>\n";
1094: }
1095: }
1096:
1097: $result .= "</select> :\n";
1098:
1099: $result .= "<select name='${var}minute'>\n";
1100: for ($i = 0; $i < 60; $i++) {
1101: my $printedMinute = $i;
1102: if ($i < 10) {
1103: $printedMinute = "0" . $printedMinute;
1104: }
1105: if ($date->min == $i) {
1106: $result .= "<option selected>";
1107: } else {
1108: $result .= "<option>";
1109: }
1110: $result .= "$printedMinute</option>\n";
1111: }
1112: $result .= "</select>\n";
1113: }
1114:
1115: return $result;
1116:
1117: }
1118: # If a NEXTSTATE was given, switch to it
1119: sub postprocess {
1120: my $self = shift;
1121: my $var = $self->{'variable'};
1122: my $month = $ENV{'form.' . $var . 'month'};
1123: my $day = $ENV{'form.' . $var . 'day'};
1124: my $year = $ENV{'form.' . $var . 'year'};
1125: my $min = 0;
1126: my $hour = 0;
1127: if ($self->{'hoursminutes'}) {
1128: $min = $ENV{'form.' . $var . 'minute'};
1129: $hour = $ENV{'form.' . $var . 'hour'};
1130: }
1131:
1132: my $chosenDate = Time::Local::timelocal(0, $min, $hour, $day, $month, $year);
1133: # Check to make sure that the date was not automatically co-erced into a
1134: # valid date, as we want to flag that as an error
1135: # This happens for "Feb. 31", for instance, which is coerced to March 2 or
1136: # 3, depending on if it's a leapyear
1137: my $checkDate = localtime($chosenDate);
1138:
1139: if ($checkDate->mon != $month || $checkDate->mday != $day ||
1140: $checkDate->year + 1900 != $year) {
1141: $self->{ERROR_MSG} = "Can't use " . $months[$month] . " $day, $year as a "
1142: . "date because it doesn't exist. Please enter a valid date.";
1.6 bowersj2 1143: return 0;
1.5 bowersj2 1144: }
1145:
1146: $helper->{VARS}->{$var} = $chosenDate;
1147:
1148: if (defined($self->{NEXTSTATE})) {
1149: $helper->changeState($self->{NEXTSTATE});
1150: }
1.6 bowersj2 1151:
1152: return 1;
1.5 bowersj2 1153: }
1154: 1;
1155:
1156: package Apache::lonhelper::resource;
1157:
1158: =pod
1159:
1160: =head2 Element: resource
1161:
1162: <resource> elements allow the user to select one or multiple resources
1163: from the current course. You can filter out which resources they can view,
1164: and filter out which resources they can select. The course will always
1165: be displayed fully expanded, because of the difficulty of maintaining
1166: selections across folder openings and closings. If this is fixed, then
1167: the user can manipulate the folders.
1168:
1169: <resource> takes the standard variable attribute to control what helper
1170: variable stores the results. It also takes a "multichoice" attribute,
1171: which controls whether the user can select more then one resource.
1172:
1173: B<SUB-TAGS>
1174:
1175: =over 4
1176:
1177: =item * <filterfunc>: If you want to filter what resources are displayed
1178: to the user, use a filter func. The <filterfunc> tag should contain
1179: Perl code that when wrapped with "sub { my $res = shift; " and "}" is
1180: a function that returns true if the resource should be displayed,
1181: and false if it should be skipped. $res is a resource object.
1182: (See Apache::lonnavmaps documentation for information about the
1183: resource object.)
1184:
1185: =item * <choicefunc>: Same as <filterfunc>, except that controls whether
1186: the given resource can be chosen. (It is almost always a good idea to
1187: show the user the folders, for instance, but you do not always want to
1188: let the user select them.)
1189:
1190: =item * <nextstate>: Standard nextstate behavior.
1191:
1192: =item * <valuefunc>: This function controls what is returned by the resource
1193: when the user selects it. Like filterfunc and choicefunc, it should be
1194: a function fragment that when wrapped by "sub { my $res = shift; " and
1195: "}" returns a string representing what you want to have as the value. By
1196: default, the value will be the resource ID of the object ($res->{ID}).
1197:
1198: =back
1199:
1200: =cut
1201:
1202: no strict;
1203: @ISA = ("Apache::lonhelper::element");
1204: use strict;
1205:
1206: BEGIN {
1.7 ! bowersj2 1207: &Apache::lonhelper::register('Apache::lonhelper::resource',
1.5 bowersj2 1208: ('resource', 'filterfunc',
1209: 'choicefunc', 'valuefunc'));
1210: }
1211:
1212: sub new {
1213: my $ref = Apache::lonhelper::element->new();
1214: bless($ref);
1215: }
1216:
1217: # CONSTRUCTION: Construct the message element from the XML
1218: sub start_resource {
1219: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1220:
1221: if ($target ne 'helper') {
1222: return '';
1223: }
1224:
1225: $paramHash->{'variable'} = $token->[2]{'variable'};
1226: $helper->declareVar($paramHash->{'variable'});
1227: return '';
1228: }
1229:
1230: sub end_resource {
1231: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1232:
1233: if ($target ne 'helper') {
1234: return '';
1235: }
1236: if (!defined($paramHash->{FILTER_FUNC})) {
1237: $paramHash->{FILTER_FUNC} = sub {return 1;};
1238: }
1239: if (!defined($paramHash->{CHOICE_FUNC})) {
1240: $paramHash->{CHOICE_FUNC} = sub {return 1;};
1241: }
1242: if (!defined($paramHash->{VALUE_FUNC})) {
1243: $paramHash->{VALUE_FUNC} = sub {my $res = shift; return $res->{ID}; };
1244: }
1245: Apache::lonhelper::resource->new();
1.4 bowersj2 1246: return '';
1247: }
1248:
1.5 bowersj2 1249: sub start_filterfunc {
1250: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1251:
1252: if ($target ne 'helper') {
1253: return '';
1254: }
1255:
1256: my $contents = Apache::lonxml::get_all_text('/filterfunc',
1257: $parser);
1258: $contents = 'sub { my $res = shift; ' . $contents . '}';
1259: $paramHash->{FILTER_FUNC} = eval $contents;
1260: }
1261:
1262: sub end_filterfunc { return ''; }
1263:
1264: sub start_choicefunc {
1265: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1266:
1267: if ($target ne 'helper') {
1268: return '';
1269: }
1270:
1271: my $contents = Apache::lonxml::get_all_text('/choicefunc',
1272: $parser);
1273: $contents = 'sub { my $res = shift; ' . $contents . '}';
1274: $paramHash->{CHOICE_FUNC} = eval $contents;
1275: }
1276:
1277: sub end_choicefunc { return ''; }
1278:
1279: sub start_valuefunc {
1280: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1281:
1282: if ($target ne 'helper') {
1283: return '';
1284: }
1285:
1286: my $contents = Apache::lonxml::get_all_text('/valuefunc',
1287: $parser);
1288: $contents = 'sub { my $res = shift; ' . $contents . '}';
1289: $paramHash->{VALUE_FUNC} = eval $contents;
1290: }
1291:
1292: sub end_valuefunc { return ''; }
1293:
1294: # A note, in case I don't get to this before I leave.
1295: # If someone complains about the "Back" button returning them
1296: # to the previous folder state, instead of returning them to
1297: # the previous helper state, the *correct* answer is for the helper
1298: # to keep track of how many times the user has manipulated the folders,
1299: # and feed that to the history.go() call in the helper rendering routines.
1300: # If done correctly, the helper itself can keep track of how many times
1301: # it renders the same states, so it doesn't go in just this state, and
1302: # you can lean on the browser back button to make sure it all chains
1303: # correctly.
1304: # Right now, though, I'm just forcing all folders open.
1305:
1306: sub render {
1307: my $self = shift;
1308: my $result = "";
1309: my $var = $self->{'variable'};
1310: my $curVal = $helper->{VARS}->{$var};
1311:
1312: if (defined $self->{ERROR_MSG}) {
1313: $result .= '<font color="#FF0000">' . $self->{ERROR_MSG} . '</font><br /><br />';
1314: }
1315:
1316: my $filterFunc = $self->{FILTER_FUNC};
1317: my $choiceFunc = $self->{CHOICE_FUNC};
1318: my $valueFunc = $self->{VALUE_FUNC};
1319:
1320: # Create the composite function that renders the column on the nav map
1321: # have to admit any language that lets me do this can't be all bad
1322: # - Jeremy (Pythonista) ;-)
1323: my $checked = 0;
1324: my $renderColFunc = sub {
1325: my ($resource, $part, $params) = @_;
1326:
1327: if (!&$choiceFunc($resource)) {
1328: return '<td> </td>';
1329: } else {
1330: my $col = "<td><input type='radio' name='${var}.forminput' ";
1331: if (!$checked) {
1332: $col .= "checked ";
1333: $checked = 1;
1334: }
1335: $col .= "value='" .
1336: HTML::Entities::encode(&$valueFunc($resource))
1337: . "' /></td>";
1338: return $col;
1339: }
1340: };
1341:
1342: $ENV{'form.condition'} = 1;
1343: $result .=
1344: &Apache::lonnavmaps::render( { 'cols' => [$renderColFunc,
1345: Apache::lonnavmaps::resource()],
1346: 'showParts' => 0,
1347: 'url' => $helper->{URL},
1348: 'filterFunc' => $filterFunc,
1349: 'resource_no_folder_link' => 1 }
1350: );
1351:
1352: return $result;
1353: }
1354:
1355: sub postprocess {
1356: my $self = shift;
1357: if (defined($self->{NEXTSTATE})) {
1358: $helper->changeState($self->{NEXTSTATE});
1359: }
1.6 bowersj2 1360:
1361: return 1;
1.5 bowersj2 1362: }
1363:
1364: 1;
1365:
1366: package Apache::lonhelper::student;
1367:
1368: =pod
1369:
1370: =head2 Element: student
1371:
1372: Student elements display a choice of students enrolled in the current
1373: course. Currently it is primitive; this is expected to evolve later.
1374:
1375: Student elements take two attributes: "variable", which means what
1376: it usually does, and "multichoice", which if true allows the user
1377: to select multiple students.
1378:
1379: =cut
1380:
1381: no strict;
1382: @ISA = ("Apache::lonhelper::element");
1383: use strict;
1384:
1385:
1386:
1387: BEGIN {
1.7 ! bowersj2 1388: &Apache::lonhelper::register('Apache::lonhelper::student',
1.5 bowersj2 1389: ('student'));
1390: }
1391:
1392: sub new {
1393: my $ref = Apache::lonhelper::element->new();
1394: bless($ref);
1395: }
1.4 bowersj2 1396:
1.5 bowersj2 1397: sub start_student {
1.4 bowersj2 1398: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1399:
1400: if ($target ne 'helper') {
1401: return '';
1402: }
1403:
1.5 bowersj2 1404: $paramHash->{'variable'} = $token->[2]{'variable'};
1405: $helper->declareVar($paramHash->{'variable'});
1406: $paramHash->{'multichoice'} = $token->[2]{'multichoice'};
1407: }
1408:
1409: sub end_student {
1410: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1411:
1412: if ($target ne 'helper') {
1413: return '';
1414: }
1415: Apache::lonhelper::student->new();
1.3 bowersj2 1416: }
1.5 bowersj2 1417:
1418: sub render {
1419: my $self = shift;
1420: my $result = '';
1421: my $buttons = '';
1422:
1423: if ($self->{'multichoice'}) {
1424: $result = <<SCRIPT;
1425: <script>
1426: function checkall(value) {
1427: for (i=0; i<document.forms.wizform.elements.length; i++) {
1428: document.forms.wizform.elements[i].checked=value;
1429: }
1430: }
1431: </script>
1432: SCRIPT
1433: $buttons = <<BUTTONS;
1434: <br />
1435: <input type="button" onclick="checkall(true)" value="Select All" />
1436: <input type="button" onclick="checkall(false)" value="Unselect All" />
1437: <br />
1438: BUTTONS
1439: }
1440:
1441: if (defined $self->{ERROR_MSG}) {
1442: $result .= '<font color="#FF0000">' . $self->{ERROR_MSG} . '</font><br /><br />';
1443: }
1444:
1445: # Load up the students
1446: my $choices = &Apache::loncoursedata::get_classlist();
1447:
1448: my @keys = keys %{$choices};
1449:
1450: # Constants
1451: my $section = Apache::loncoursedata::CL_SECTION();
1452: my $fullname = Apache::loncoursedata::CL_FULLNAME();
1453:
1454: # Sort by: Section, name
1455: @keys = sort {
1456: if ($choices->{$a}->[$section] ne $choices->{$b}->[$section]) {
1457: return $choices->{$a}->[$section] cmp $choices->{$b}->[$section];
1458: }
1459: return $choices->{$a}->[$fullname] cmp $choices->{$b}->[$fullname];
1460: } @keys;
1461:
1462: my $type = 'radio';
1463: if ($self->{'multichoice'}) { $type = 'checkbox'; }
1464: $result .= "<table cellspacing='2' cellpadding='2' border='0'>\n";
1465: $result .= "<tr><td></td><td align='center'><b>Student Name</b></td>".
1466: "<td align='center'><b>Section</b></td></tr>";
1467:
1468: my $checked = 0;
1469: foreach (@keys) {
1470: $result .= "<tr><td><input type='$type' name='" .
1471: $self->{'variable'} . '.forminput' . "'";
1472:
1473: if (!$self->{'multichoice'} && !$checked) {
1474: $result .= " checked ";
1475: $checked = 1;
1476: }
1477: $result .=
1478: " value='" . HTML::Entities::encode($_)
1479: . "' /></td><td>"
1480: . HTML::Entities::encode($choices->{$_}->[$fullname])
1481: . "</td><td align='center'>"
1482: . HTML::Entities::encode($choices->{$_}->[$section])
1483: . "</td></tr>\n";
1484: }
1485:
1486: $result .= "</table>\n\n";
1487: $result .= $buttons;
1.4 bowersj2 1488:
1.5 bowersj2 1489: return $result;
1490: }
1491:
1.6 bowersj2 1492: sub postprocess {
1493: my $self = shift;
1494:
1495: my $result = $ENV{'form.' . $self->{'variable'} . '.forminput'};
1496: if (!$result) {
1497: $self->{ERROR_MSG} = 'You must choose at least one student '.
1498: 'to continue.';
1499: return 0;
1500: }
1501:
1502: if ($self->{'multichoice'}) {
1503: $self->process_multiple_choices($self->{'variable'}.'.forminput',
1504: $self->{'variable'});
1505: }
1506: if (defined($self->{NEXTSTATE})) {
1507: $helper->changeState($self->{NEXTSTATE});
1508: }
1509:
1510: return 1;
1511: }
1512:
1.5 bowersj2 1513: 1;
1514:
1515: package Apache::lonhelper::files;
1516:
1517: =pod
1518:
1519: =head2 Element: files
1520:
1521: files allows the users to choose files from a given directory on the
1522: server. It is always multichoice and stores the result as a triple-pipe
1523: delimited entry in the helper variables.
1524:
1525: Since it is extremely unlikely that you can actually code a constant
1526: representing the directory you wish to allow the user to search, <files>
1527: takes a subroutine that returns the name of the directory you wish to
1528: have the user browse.
1529:
1530: files accepts the attribute "variable" to control where the files chosen
1531: are put. It accepts the attribute "multichoice" as the other attribute,
1532: defaulting to false, which if true will allow the user to select more
1533: then one choice.
1534:
1535: <files> accepts three subtags. One is the "nextstate" sub-tag that works
1536: as it does with the other tags. Another is a <filechoice> sub tag that
1537: is Perl code that, when surrounded by "sub {" and "}" will return a
1538: string representing what directory on the server to allow the user to
1539: choose files from. Finally, the <filefilter> subtag should contain Perl
1540: code that when surrounded by "sub { my $filename = shift; " and "}",
1541: returns a true value if the user can pick that file, or false otherwise.
1542: The filename passed to the function will be just the name of the file,
1543: with no path info.
1544:
1545: =cut
1546:
1547: no strict;
1548: @ISA = ("Apache::lonhelper::element");
1549: use strict;
1550:
1551: BEGIN {
1.7 ! bowersj2 1552: &Apache::lonhelper::register('Apache::lonhelper::files',
! 1553: ('files', 'filechoice', 'filefilter'));
1.5 bowersj2 1554: }
1555:
1556: sub new {
1557: my $ref = Apache::lonhelper::element->new();
1558: bless($ref);
1559: }
1560:
1561: sub start_files {
1562: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1563:
1564: if ($target ne 'helper') {
1565: return '';
1566: }
1567: $paramHash->{'variable'} = $token->[2]{'variable'};
1568: $helper->declareVar($paramHash->{'variable'});
1569: $paramHash->{'multichoice'} = $token->[2]{'multichoice'};
1570: }
1571:
1572: sub end_files {
1573: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1574:
1575: if ($target ne 'helper') {
1576: return '';
1577: }
1578: if (!defined($paramHash->{FILTER_FUNC})) {
1579: $paramHash->{FILTER_FUNC} = sub { return 1; };
1580: }
1581: Apache::lonhelper::files->new();
1582: }
1583:
1584: sub start_filechoice {
1585: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1586:
1587: if ($target ne 'helper') {
1588: return '';
1589: }
1590: $paramHash->{'filechoice'} = Apache::lonxml::get_all_text('/filechoice',
1591: $parser);
1592: }
1593:
1594: sub end_filechoice { return ''; }
1595:
1596: sub start_filefilter {
1597: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1598:
1599: if ($target ne 'helper') {
1600: return '';
1601: }
1602:
1603: my $contents = Apache::lonxml::get_all_text('/filefilter',
1604: $parser);
1605: $contents = 'sub { my $filename = shift; ' . $contents . '}';
1606: $paramHash->{FILTER_FUNC} = eval $contents;
1607: }
1608:
1609: sub end_filefilter { return ''; }
1.3 bowersj2 1610:
1611: sub render {
1612: my $self = shift;
1.5 bowersj2 1613: my $result = '';
1614: my $var = $self->{'variable'};
1615:
1616: my $subdirFunc = eval('sub {' . $self->{'filechoice'} . '}');
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: }
1.3 bowersj2 1655:
1.5 bowersj2 1656: $result .= $buttons;
1657:
1.6 bowersj2 1658: if (defined $self->{ERROR_MSG}) {
1659: $result .= '<br /><font color="#FF0000">' . $self->{ERROR_MSG} . '</font><br /><br />';
1660: }
1661:
1.5 bowersj2 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;
1.4 bowersj2 1700: }
1.5 bowersj2 1701:
1.4 bowersj2 1702: sub postprocess {
1703: my $self = shift;
1.6 bowersj2 1704: my $result = $ENV{'form.' . $self->{'variable'} . '.forminput'};
1705: if (!$result) {
1706: $self->{ERROR_MSG} = 'You must choose at least one file '.
1707: 'to continue.';
1708: return 0;
1709: }
1710:
1.5 bowersj2 1711: if ($self->{'multichoice'}) {
1712: $self->process_multiple_choices($self->{'variable'}.'.forminput',
1713: $self->{'variable'});
1714: }
1715: if (defined($self->{NEXTSTATE})) {
1716: $helper->changeState($self->{NEXTSTATE});
1.3 bowersj2 1717: }
1.6 bowersj2 1718:
1719: return 1;
1.3 bowersj2 1720: }
1.5 bowersj2 1721:
1.4 bowersj2 1722: 1;
1.3 bowersj2 1723:
1.1 bowersj2 1724: __END__
1.3 bowersj2 1725:
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