mod/lesson/renderer.php

   1 <?php
   2
   3 // This file is part of Moodle - http://moodle.org/
   4 //
   5 // Moodle is free software: you can redistribute it and/or modify
   6 // it under the terms of the GNU General Public License as published by
   7 // the Free Software Foundation, either version 3 of the License, or
   8 // (at your option) any later version.
   9 //
  10 // Moodle is distributed in the hope that it will be useful,
  11 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 // GNU General Public License for more details.
  14 //
  15 // You should have received a copy of the GNU General Public License
  16 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  17
  18 /**
  19  * Moodle renderer used to display special elements of the lesson module
  20  *
  21  * @package mod_lesson
  22  * @copyright  2009 Sam Hemelryk
  23  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  24  **/
  25
  26 defined('MOODLE_INTERNAL') || die();
  27
  28 class mod_lesson_renderer extends plugin_renderer_base {
  29     /**
  30      * Returns the header for the lesson module
  31      *
  32      * @param lesson $lesson a lesson object.
  33      * @param string $currenttab current tab that is shown.
  34      * @param bool   $extraeditbuttons if extra edit buttons should be displayed.
  35      * @param int    $lessonpageid id of the lesson page that needs to be displayed.
  36      * @param string $extrapagetitle String to appent to the page title.
  37      * @return string
  38      */
  39     public function header($lesson, $cm, $currenttab = '', $extraeditbuttons = false, $lessonpageid = null, $extrapagetitle = null) {
  40         global $CFG;
  41
  42         $activityname = format_string($lesson->name, true, $lesson->course);
  43         if (empty($extrapagetitle)) {
  44             $title = $this->page->course->shortname.": ".$activityname;
  45         } else {
  46             $title = $this->page->course->shortname.": ".$activityname.": ".$extrapagetitle;
  47         }
  48
  49         // Build the buttons
  50         $context = context_module::instance($cm->id);
  51
  52     /// Header setup
  53         $this->page->set_title($title);
  54         $this->page->set_heading($this->page->course->fullname);
  55         lesson_add_header_buttons($cm, $context, $extraeditbuttons, $lessonpageid);
  56         $output = $this->output->header();
  57
  58         if (has_capability('mod/lesson:manage', $context)) {
  59             $output .= $this->output->heading_with_help($activityname, 'overview', 'lesson');
  60
  61             if (!empty($currenttab)) {
  62                 ob_start();
  63                 include($CFG->dirroot.'/mod/lesson/tabs.php');
  64                 $output .= ob_get_contents();
  65                 ob_end_clean();
  66             }
  67         } else {
  68             $output .= $this->output->heading($activityname);
  69         }
  70
  71         foreach ($lesson->messages as $message) {
  72             $output .= $this->output->notification($message[0], $message[1], $message[2]);
  73         }
  74
  75         return $output;
  76     }
  77
  78     /**
  79      * Returns the footer
  80      * @return string
  81      */
  82     public function footer() {
  83         return $this->output->footer();
  84     }
  85
  86     /**
  87      * Returns HTML for a lesson inaccessible message
  88      *
  89      * @param string $message
  90      * @return <type>
  91      */
  92     public function lesson_inaccessible($message) {
  93         global $CFG;
  94         $output  =  $this->output->box_start('generalbox boxaligncenter');
  95         $output .=  $this->output->box_start('center');
  96         $output .=  $message;
  97         $output .=  $this->output->box('<a href="'.$CFG->wwwroot.'/course/view.php?id='. $this->page->course->id .'">'. get_string('returnto', 'lesson', format_string($this->page->course->fullname, true)) .'</a>', 'lessonbutton standardbutton');
  98         $output .=  $this->output->box_end();
  99         $output .=  $this->output->box_end();
 100         return $output;
 101     }
 102
 103     /**
 104      * Returns HTML to prompt the user to log in
 105      * @param lesson $lesson
 106      * @param bool $failedattempt
 107      * @return string
 108      */
 109     public function login_prompt(lesson $lesson, $failedattempt = false) {
 110         global $CFG;
 111         $output  = $this->output->box_start('password-form');
 112         $output .= $this->output->box_start('generalbox boxaligncenter');
 113         $output .=  '<form id="password" method="post" action="'.$CFG->wwwroot.'/mod/lesson/view.php" autocomplete="off">';
 114         $output .=  '<fieldset class="invisiblefieldset center">';
 115         $output .=  '<input type="hidden" name="id" value="'. $this->page->cm->id .'" />';
 116         $output .=  '<input type="hidden" name="sesskey" value="'.sesskey().'" />';
 117         if ($failedattempt) {
 118             $output .=  $this->output->notification(get_string('loginfail', 'lesson'));
 119         }
 120         $output .= get_string('passwordprotectedlesson', 'lesson', format_string($lesson->name)).'<br /><br />';
 121         $output .= get_string('enterpassword', 'lesson')." <input type=\"password\" name=\"userpassword\" /><br /><br />";
 122         $output .= "<div class='lessonbutton standardbutton submitbutton'><input type='submit' value='".get_string('continue', 'lesson')."' /></div>";
 123         $output .= " <div class='lessonbutton standardbutton submitbutton'><input type='submit' name='backtocourse' value='".get_string('cancel', 'lesson')."' /></div>";
 124         $output .=  '</fieldset></form>';
 125         $output .=  $this->output->box_end();
 126         $output .=  $this->output->box_end();
 127         return $output;
 128     }
 129
 130     /**
 131      * Returns HTML to display dependancy errors
 132      *
 133      * @param object $dependentlesson
 134      * @param array $errors
 135      * @return string
 136      */
 137     public function dependancy_errors($dependentlesson, $errors) {
 138         $output  = $this->output->box_start('generalbox boxaligncenter');
 139         $output .= get_string('completethefollowingconditions', 'lesson', $dependentlesson->name);
 140         $output .= $this->output->box(implode('<br />'.get_string('and', 'lesson').'<br />', $errors),'center');
 141         $output .= $this->output->box_end();
 142         return $output;
 143     }
 144
 145     /**
 146      * Returns HTML to display a message
 147      * @param string $message
 148      * @param single_button $button
 149      * @return string
 150      */
 151     public function message($message, single_button $button = null) {
 152         $output  = $this->output->box_start('generalbox boxaligncenter');
 153         $output .= $message;
 154         if ($button !== null) {
 155             $output .= $this->output->box($this->output->render($button), 'lessonbutton standardbutton');
 156         }
 157         $output .= $this->output->box_end();
 158         return $output;
 159     }
 160
 161     /**
 162      * Returns HTML to display a continue button
 163      * @param lesson $lesson
 164      * @param int $lastpageseen
 165      * @return string
 166      */
 167     public function continue_links(lesson $lesson, $lastpageseenid) {
 168         global $CFG;
 169         $output = $this->output->box(get_string('youhaveseen','lesson'), 'generalbox boxaligncenter');
 170         $output .= $this->output->box_start('center');
 171
 172         $yeslink = html_writer::link(new moodle_url('/mod/lesson/view.php', array('id'=>$this->page->cm->id, 'pageid'=>$lastpageseenid, 'startlastseen'=>'yes')), get_string('yes'));
 173         $output .= html_writer::tag('span', $yeslink, array('class'=>'lessonbutton standardbutton'));
 174         $output .= '&nbsp;';
 175
 176         $nolink = html_writer::link(new moodle_url('/mod/lesson/view.php', array('id'=>$this->page->cm->id, 'pageid'=>$lesson->firstpageid, 'startlastseen'=>'no')), get_string('no'));
 177         $output .= html_writer::tag('span', $nolink, array('class'=>'lessonbutton standardbutton'));
 178
 179         $output .= $this->output->box_end();
 180         return $output;
 181     }
 182
 183     /**
 184      * Returns HTML to display a page to the user
 185      * @param lesson $lesson
 186      * @param lesson_page $page
 187      * @param object $attempt
 188      * @return string
 189      */
 190     public function display_page(lesson $lesson, lesson_page $page, $attempt) {
 191         // We need to buffer here as there is an mforms display call
 192         ob_start();
 193         echo $page->display($this, $attempt);
 194         $output = ob_get_contents();
 195         ob_end_clean();
 196         return $output;
 197     }
 198
 199     /**
 200      * Returns HTML to display a collapsed edit form
 201      *
 202      * @param lesson $lesson
 203      * @param int $pageid
 204      * @return string
 205      */
 206     public function display_edit_collapsed(lesson $lesson, $pageid) {
 207         global $DB, $CFG;
 208
 209         $manager = lesson_page_type_manager::get($lesson);
 210         $qtypes = $manager->get_page_type_strings();
 211         $npages = count($lesson->load_all_pages());
 212
 213         $table = new html_table();
 214         $table->head = array(get_string('pagetitle', 'lesson'), get_string('qtype', 'lesson'), get_string('jumps', 'lesson'), get_string('actions', 'lesson'));
 215         $table->align = array('left', 'left', 'left', 'center');
 216         $table->wrap = array('', 'nowrap', '', 'nowrap');
 217         $table->tablealign = 'center';
 218         $table->cellspacing = 0;
 219         $table->cellpadding = '2px';
 220         $table->width = '80%';
 221         $table->data = array();
 222
 223         $canedit = has_capability('mod/lesson:edit', context_module::instance($this->page->cm->id));
 224
 225         while ($pageid != 0) {
 226             $page = $lesson->load_page($pageid);
 227             $data = array();
 228             $url = new moodle_url('/mod/lesson/edit.php', array(
 229                 'id'     => $this->page->cm->id,
 230                 'mode'   => 'single',
 231                 'pageid' => $page->id
 232             ));
 233             $data[] = html_writer::link($url, format_string($page->title, true), array('id' => 'lesson-' . $page->id));
 234             $data[] = $qtypes[$page->qtype];
 235             $data[] = implode("<br />\n", $page->jumps);
 236             if ($canedit) {
 237                 $data[] = $this->page_action_links($page, $npages, true);
 238             } else {
 239                 $data[] = '';
 240             }
 241             $table->data[] = $data;
 242             $pageid = $page->nextpageid;
 243         }
 244
 245         return html_writer::table($table);
 246     }
 247
 248     /**
 249      * Returns HTML to display the full edit page
 250      *
 251      * @param lesson $lesson
 252      * @param int $pageid
 253      * @param int $prevpageid
 254      * @param bool $single
 255      * @return string
 256      */
 257     public function display_edit_full(lesson $lesson, $pageid, $prevpageid, $single=false) {
 258         global $DB, $CFG;
 259
 260         $manager = lesson_page_type_manager::get($lesson);
 261         $qtypes = $manager->get_page_type_strings();
 262         $npages = count($lesson->load_all_pages());
 263         $canedit = has_capability('mod/lesson:edit', context_module::instance($this->page->cm->id));
 264
 265         $content = '';
 266         if ($canedit) {
 267             $content = $this->add_page_links($lesson, $prevpageid);
 268         }
 269
 270         $options = new stdClass;
 271         $options->noclean = true;
 272
 273         while ($pageid != 0 && $single!=='stop') {
 274             $page = $lesson->load_page($pageid);
 275
 276             $pagetable = new html_table();
 277             $pagetable->align = array('right','left');
 278             $pagetable->width = '100%';
 279             $pagetable->tablealign = 'center';
 280             $pagetable->cellspacing = 0;
 281             $pagetable->cellpadding = '5px';
 282             $pagetable->data = array();
 283             $pagetable->id = 'lesson-' . $pageid;
 284
 285             $pageheading = new html_table_cell();
 286
 287             $pageheading->text = format_string($page->title);
 288             if ($canedit) {
 289                 $pageheading->text .= ' '.$this->page_action_links($page, $npages);
 290             }
 291             $pageheading->style = 'text-align:center';
 292             $pageheading->colspan = 2;
 293             $pageheading->scope = 'col';
 294             $pagetable->head = array($pageheading);
 295
 296             $cell = new html_table_cell();
 297             $cell->colspan = 2;
 298             $cell->style = 'text-align:left';
 299             $cell->text = $page->contents;
 300             $pagetable->data[] = new html_table_row(array($cell));
 301
 302             $cell = new html_table_cell();
 303             $cell->colspan = 2;
 304             $cell->style = 'text-align:center';
 305             $cell->text = '<strong>'.$qtypes[$page->qtype] . $page->option_description_string().'</strong>';
 306             $pagetable->data[] = new html_table_row(array($cell));
 307
 308             $pagetable = $page->display_answers($pagetable);
 309
 310             $content .= html_writer::start_tag('div', array('class' => 'no-overflow'));
 311             $content .= html_writer::table($pagetable);
 312             $content .= html_writer::end_tag('div');
 313
 314             if ($canedit) {
 315                 $content .= $this->add_page_links($lesson, $pageid);
 316             }
 317
 318             // check the prev links - fix (silently) if necessary - there was a bug in
 319             // versions 1 and 2 when add new pages. Not serious then as the backwards
 320             // links were not used in those versions
 321             if ($page->prevpageid != $prevpageid) {
 322                 // fix it
 323                 $DB->set_field("lesson_pages", "prevpageid", $prevpageid, array("id" => $page->id));
 324                 debugging("<p>***prevpageid of page $page->id set to $prevpageid***");
 325             }
 326
 327             $prevpageid = $page->id;
 328             $pageid = $page->nextpageid;
 329
 330             if ($single === true) {
 331                 $single = 'stop';
 332             }
 333
 334         }
 335
 336         return $this->output->box($content, 'edit_pages_box');
 337     }
 338
 339     /**
 340      * Returns HTML to display the add page links
 341      *
 342      * @param lesson $lesson
 343      * @param int $prevpageid
 344      * @return string
 345      */
 346     public function add_page_links(lesson $lesson, $prevpageid=false) {
 347         global $CFG;
 348
 349         $links = array();
 350
 351         $importquestionsurl = new moodle_url('/mod/lesson/import.php',array('id'=>$this->page->cm->id, 'pageid'=>$prevpageid));
 352         $links[] = html_writer::link($importquestionsurl, get_string('importquestions', 'lesson'));
 353
 354         $manager = lesson_page_type_manager::get($lesson);
 355         foreach($manager->get_add_page_type_links($prevpageid) as $link) {
 356             $links[] = html_writer::link($link['addurl'], $link['name']);
 357         }
 358
 359         $addquestionurl = new moodle_url('/mod/lesson/editpage.php', array('id'=>$this->page->cm->id, 'pageid'=>$prevpageid));
 360         $links[] = html_writer::link($addquestionurl, get_string('addaquestionpagehere', 'lesson'));
 361
 362         return $this->output->box(implode(" | \n", $links), 'addlinks');
 363     }
 364
 365     /**
 366      * Return HTML to display add first page links
 367      * @param lesson $lesson
 368      * @return string
 369      */
 370     public function add_first_page_links(lesson $lesson) {
 371         global $CFG;
 372         $prevpageid = 0;
 373
 374         $output = $this->output->heading(get_string("whatdofirst", "lesson"), 3);
 375         $links = array();
 376
 377         $importquestionsurl = new moodle_url('/mod/lesson/import.php',array('id'=>$this->page->cm->id, 'pageid'=>$prevpageid));
 378         $links[] = html_writer::link($importquestionsurl, get_string('importquestions', 'lesson'));
 379
 380         $manager = lesson_page_type_manager::get($lesson);
 381         foreach ($manager->get_add_page_type_links($prevpageid) as $link) {
 382             $link['addurl']->param('firstpage', 1);
 383             $links[] = html_writer::link($link['addurl'], $link['name']);
 384         }
 385
 386         $addquestionurl = new moodle_url('/mod/lesson/editpage.php', array('id'=>$this->page->cm->id, 'pageid'=>$prevpageid, 'firstpage'=>1));
 387         $links[] = html_writer::link($addquestionurl, get_string('addaquestionpage', 'lesson'));
 388
 389         return $this->output->box($output.'<p>'.implode('</p><p>', $links).'</p>', 'generalbox firstpageoptions');
 390     }
 391
 392     /**
 393      * Returns HTML to display action links for a page
 394      *
 395      * @param lesson_page $page
 396      * @param bool $printmove
 397      * @param bool $printaddpage
 398      * @return string
 399      */
 400     public function page_action_links(lesson_page $page, $printmove, $printaddpage=false) {
 401         global $CFG;
 402
 403         $actions = array();
 404
 405         if ($printmove) {
 406             $url = new moodle_url('/mod/lesson/lesson.php',
 407                     array('id' => $this->page->cm->id, 'action' => 'move', 'pageid' => $page->id, 'sesskey' => sesskey()));
 408             $label = get_string('movepagenamed', 'lesson', format_string($page->title));
 409             $img = html_writer::img($this->output->pix_url('t/move'), $label, array('class' => 'iconsmall'));
 410             $actions[] = html_writer::link($url, $img, array('title' => $label));
 411         }
 412         $url = new moodle_url('/mod/lesson/editpage.php', array('id' => $this->page->cm->id, 'pageid' => $page->id, 'edit' => 1));
 413         $label = get_string('updatepagenamed', 'lesson', format_string($page->title));
 414         $img = html_writer::img($this->output->pix_url('t/edit'), $label, array('class' => 'iconsmall'));
 415         $actions[] = html_writer::link($url, $img, array('title' => $label));
 416
 417         $url = new moodle_url('/mod/lesson/view.php', array('id' => $this->page->cm->id, 'pageid' => $page->id));
 418         $label = get_string('previewpagenamed', 'lesson', format_string($page->title));
 419         $img = html_writer::img($this->output->pix_url('t/preview'), $label, array('class' => 'iconsmall'));
 420         $actions[] = html_writer::link($url, $img, array('title' => $label));
 421
 422         $url = new moodle_url('/mod/lesson/lesson.php',
 423                 array('id' => $this->page->cm->id, 'action' => 'confirmdelete', 'pageid' => $page->id, 'sesskey' => sesskey()));
 424         $label = get_string('deletepagenamed', 'lesson', format_string($page->title));
 425         $img = html_writer::img($this->output->pix_url('t/delete'), $label, array('class' => 'iconsmall'));
 426         $actions[] = html_writer::link($url, $img, array('title' => $label));
 427
 428         if ($printaddpage) {
 429             $options = array();
 430             $manager = lesson_page_type_manager::get($page->lesson);
 431             $links = $manager->get_add_page_type_links($page->id);
 432             foreach ($links as $link) {
 433                 $options[$link['type']] = $link['name'];
 434             }
 435             $options[0] = get_string('question', 'lesson');
 436
 437             $addpageurl = new moodle_url('/mod/lesson/editpage.php', array('id'=>$this->page->cm->id, 'pageid'=>$page->id, 'sesskey'=>sesskey()));
 438             $addpageselect = new single_select($addpageurl, 'qtype', $options, null, array(''=>get_string('addanewpage', 'lesson').'...'), 'addpageafter'.$page->id);
 439             $addpageselector = $this->output->render($addpageselect);
 440         }
 441
 442         if (isset($addpageselector)) {
 443             $actions[] = $addpageselector;
 444         }
 445
 446         return implode(' ', $actions);
 447     }
 448
 449     /**
 450      * Prints the on going message to the user.
 451      *
 452      * With custom grading On, displays points
 453      * earned out of total points possible thus far.
 454      * With custom grading Off, displays number of correct
 455      * answers out of total attempted.
 456      *
 457      * @param object $lesson The lesson that the user is taking.
 458      * @return void
 459      **/
 460
 461      /**
 462       * Prints the on going message to the user.
 463       *
 464       * With custom grading On, displays points
 465       * earned out of total points possible thus far.
 466       * With custom grading Off, displays number of correct
 467       * answers out of total attempted.
 468       *
 469       * @param lesson $lesson
 470       * @return string
 471       */
 472     public function ongoing_score(lesson $lesson) {
 473         global $USER, $DB;
 474
 475         $context = context_module::instance($this->page->cm->id);
 476         if (has_capability('mod/lesson:manage', $context)) {
 477             return $this->output->box(get_string('teacherongoingwarning', 'lesson'), "ongoing center");
 478         } else {
 479             $ntries = $DB->count_records("lesson_grades", array("lessonid"=>$lesson->id, "userid"=>$USER->id));
 480             if (isset($USER->modattempts[$lesson->id])) {
 481                 $ntries--;
 482             }
 483             $gradeinfo = lesson_grade($lesson, $ntries);
 484             $a = new stdClass;
 485             if ($lesson->custom) {
 486                 $a->score = $gradeinfo->earned;
 487                 $a->currenthigh = $gradeinfo->total;
 488                 return $this->output->box(get_string("ongoingcustom", "lesson", $a), "ongoing center");
 489             } else {
 490                 $a->correct = $gradeinfo->earned;
 491                 $a->viewed = $gradeinfo->attempts;
 492                 return $this->output->box(get_string("ongoingnormal", "lesson", $a), "ongoing center");
 493             }
 494         }
 495     }
 496
 497     /**
 498      * Returns HTML to display a progress bar of progression through a lesson
 499      *
 500      * @param lesson $lesson
 501      * @return string
 502      */
 503     public function progress_bar(lesson $lesson) {
 504         global $CFG, $USER, $DB;
 505
 506         $context = context_module::instance($this->page->cm->id);
 507
 508         // lesson setting to turn progress bar on or off
 509         if (!$lesson->progressbar) {
 510             return '';
 511         }
 512
 513         // catch teachers
 514         if (has_capability('mod/lesson:manage', $context)) {
 515             return $this->output->notification(get_string('progressbarteacherwarning2', 'lesson'));
 516         }
 517
 518         if (!isset($USER->modattempts[$lesson->id])) {
 519             // all of the lesson pages
 520             $pages = $lesson->load_all_pages();
 521             foreach ($pages as $page) {
 522                 if ($page->prevpageid == 0) {
 523                     $pageid = $page->id;  // find the first page id
 524                     break;
 525                 }
 526             }
 527
 528             // current attempt number
 529             if (!$ntries = $DB->count_records("lesson_grades", array("lessonid"=>$lesson->id, "userid"=>$USER->id))) {
 530                 $ntries = 0;  // may not be necessary
 531             }
 532
 533             $viewedpageids = array();
 534             if ($attempts = $lesson->get_attempts($ntries, false)) {
 535                 foreach($attempts as $attempt) {
 536                     $viewedpageids[$attempt->pageid] = $attempt;
 537                 }
 538             }
 539
 540             $viewedbranches = array();
 541             // collect all of the branch tables viewed
 542             if ($branches = $DB->get_records("lesson_branch", array ("lessonid"=>$lesson->id, "userid"=>$USER->id, "retry"=>$ntries), 'timeseen ASC', 'id, pageid')) {
 543                 foreach($branches as $branch) {
 544                     $viewedbranches[$branch->pageid] = $branch;
 545                 }
 546                 $viewedpageids = array_merge($viewedpageids, $viewedbranches);
 547             }
 548
 549             // Filter out the following pages:
 550             //      End of Cluster
 551             //      End of Branch
 552             //      Pages found inside of Clusters
 553             // Do not filter out Cluster Page(s) because we count a cluster as one.
 554             // By keeping the cluster page, we get our 1
 555             $validpages = array();
 556             while ($pageid != 0) {
 557                 $pageid = $pages[$pageid]->valid_page_and_view($validpages, $viewedpageids);
 558             }
 559
 560             // progress calculation as a percent
 561             $progress = round(count($viewedpageids)/count($validpages), 2) * 100;
 562         } else {
 563             $progress = 100;
 564         }
 565
 566         // print out the Progress Bar.  Attempted to put as much as possible in the style sheets.
 567         $content = '<br />' . html_writer::tag('div', $progress . '%', array('class' => 'progress_bar_completed', 'style' => 'width: '. $progress . '%;'));
 568         $printprogress = html_writer::tag('div', get_string('progresscompleted', 'lesson', $progress) . $content, array('class' => 'progress_bar'));
 569
 570         return $this->output->box($printprogress, 'progress_bar');
 571     }
 572
 573     /**
 574      * Returns HTML to show the start of a slideshow
 575      * @param lesson $lesson
 576      */
 577     public function slideshow_start(lesson $lesson) {
 578         $attributes = array();
 579         $attributes['class'] = 'slideshow';
 580         $attributes['style'] = 'background-color:'.$lesson->properties()->bgcolor.';height:'.
 581                 $lesson->properties()->height.'px;width:'.$lesson->properties()->width.'px;';
 582         $output = html_writer::start_tag('div', $attributes);
 583         return $output;
 584     }
 585     /**
 586      * Returns HTML to show the end of a slideshow
 587      */
 588     public function slideshow_end() {
 589         $output = html_writer::end_tag('div');
 590         return $output;
 591     }
 592     /**
 593      * Returns a P tag containing contents
 594      * @param string $contents
 595      * @param string $class
 596      */
 597     public function paragraph($contents, $class='') {
 598         $attributes = array();
 599         if ($class !== '') {
 600             $attributes['class'] = $class;
 601         }
 602         $output = html_writer::tag('p', $contents, $attributes);
 603         return $output;
 604     }
 605 }