comment/lib.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  * Comment is helper class to add/delete comments anywhere in moodle
  20  *
  21  * @package   comment
  22  * @copyright 2010 Dongsheng Cai <dongsheng@moodle.com>
  23  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  24  */
  25
  26 class comment {
  27     /**
  28      * @var integer
  29      */
  30     private $page;
  31     /**
  32      * there may be several comment box in one page
  33      * so we need a client_id to recognize them
  34      * @var integer
  35      */
  36     private $cid;
  37     private $contextid;
  38     /**
  39      * commentarea is used to specify different
  40      * parts shared the same itemid
  41      * @var string
  42      */
  43     private $commentarea;
  44     /**
  45      * itemid is used to associate with commenting content
  46      * @var integer
  47      */
  48     private $itemid;
  49
  50     /**
  51      * this html snippet will be used as a template
  52      * to build comment content
  53      * @var string
  54      */
  55     private $template;
  56     private $context;
  57     private $courseid;
  58     /**
  59      * course module object, only be used to help find pluginname automatically
  60      * if pluginname is specified, it won't be used at all
  61      * @var string
  62      */
  63     private $cm;
  64     private $plugintype;
  65     /**
  66      * When used in module, it is recommended to use it
  67      * @var string
  68      */
  69     private $pluginname;
  70     private $viewcap;
  71     private $postcap;
  72     /**
  73      * to tell comments api where it is used
  74      * @var string
  75      */
  76     private $env;
  77     /**
  78      * to costomize link text
  79      * @var string
  80      */
  81     private $linktext;
  82
  83     // static variable will be used by non-js comments UI
  84     private static $nonjs = false;
  85     private static $comment_itemid = null;
  86     private static $comment_context = null;
  87     private static $comment_area = null;
  88         private static $comment_page = null;
  89     /**
  90      * Construct function of comment class, initialise
  91      * class members
  92      * @param object $options
  93      */
  94     public function __construct($options) {
  95         global $CFG, $DB;
  96
  97         if (empty($CFG->commentsperpage)) {
  98             $CFG->commentsperpage = 15;
  99         }
 100
 101         $this->viewcap = false;
 102         $this->postcap = false;
 103
 104         // setup client_id
 105         if (!empty($options->client_id)) {
 106             $this->cid = $options->client_id;
 107         } else {
 108             $this->cid = uniqid();
 109         }
 110
 111         // setup context
 112         if (!empty($options->context)) {
 113             $this->context = $options->context;
 114             $this->contextid = $this->context->id;
 115         } else if(!empty($options->contextid)) {
 116             $this->contextid = $options->contextid;
 117             $this->context = get_context_instance_by_id($this->contextid);
 118         } else {
 119             print_error('invalidcontext');
 120         }
 121
 122         // setup course
 123         // course will be used to generate user profile link
 124         if (!empty($options->course)) {
 125             $this->courseid = $options->course->id;
 126         } else if (!empty($options->courseid)) {
 127             $this->courseid = $options->courseid;
 128         } else {
 129             $this->courseid = SITEID;
 130         }
 131
 132         if (!empty($options->pluginname)) {
 133             $this->pluginname = $options->pluginname;
 134         }
 135
 136         // setup coursemodule
 137         if (!empty($options->cm)) {
 138             $this->cm = $options->cm;
 139         } else {
 140             $this->cm = null;
 141         }
 142
 143         // setup commentarea
 144         if (!empty($options->area)) {
 145             $this->commentarea = $options->area;
 146         }
 147
 148         // setup itemid
 149         if (!empty($options->itemid)) {
 150             $this->itemid = $options->itemid;
 151         } else {
 152             $this->itemid = 0;
 153         }
 154
 155         // setup env
 156         if (!empty($options->env)) {
 157             $this->env = $options->env;
 158         } else {
 159             $this->env = '';
 160         }
 161
 162         // setup customized linktext
 163         if (!empty($options->linktext)) {
 164             $this->linktext = $options->linktext;
 165         } else {
 166             $this->linktext = get_string('comments');
 167         }
 168         // setting post and view permissions
 169         $this->check_permissions();
 170
 171         if (!empty($options->showcount)) {
 172             $count = $this->count();
 173             if (empty($count)) {
 174                 $this->count = '';
 175             } else {
 176                 $this->count = '('.$count.')';
 177             }
 178         } else {
 179             $this->count = '';
 180         }
 181
 182         $this->setup_plugin();
 183
 184         // setup options for callback functions
 185         $this->args = new stdclass;
 186         $this->args->context     = $this->context;
 187         $this->args->courseid    = $this->courseid;
 188         $this->args->cm          = $this->cm;
 189         $this->args->commentarea = $this->commentarea;
 190         $this->args->itemid      = $this->itemid;
 191
 192         // load template
 193         $this->template = <<<EOD
 194 <div class="comment-userpicture">___picture___</div>
 195 <div class="comment-content">
 196     ___name___ - <span>___time___</span>
 197     <div>___content___</div>
 198 </div>
 199 EOD;
 200         if (!empty($this->plugintype)) {
 201             $this->template = plugin_callback($this->plugintype, $this->pluginname, FEATURE_COMMENT, 'template', $this->args, $this->template);
 202         }
 203
 204         unset($options);
 205     }
 206
 207     /**
 208      * Receive nonjs comment parameters
 209      */
 210     public static function init() {
 211         global $PAGE, $CFG;
 212         // setup variables for non-js interface
 213         self::$nonjs = optional_param('nonjscomment', '', PARAM_ALPHA);
 214         self::$comment_itemid  = optional_param('comment_itemid',  '', PARAM_INT);
 215         self::$comment_context = optional_param('comment_context', '', PARAM_INT);
 216                 self::$comment_page    = optional_param('comment_page',    '', PARAM_INT);
 217         self::$comment_area    = optional_param('comment_area',    '', PARAM_ALPHAEXT);
 218
 219         $PAGE->requires->string_for_js('addcomment', 'moodle');
 220         $PAGE->requires->string_for_js('deletecomment', 'moodle');
 221         $PAGE->requires->string_for_js('comments', 'moodle');
 222     }
 223
 224     /**
 225      * Setup plugin type and plugin name
 226      */
 227     private function setup_plugin() {
 228         global $DB;
 229         // blog needs to set env as "blog"
 230         if ($this->env == 'blog') {
 231             $this->plugintype = 'moodle';
 232             $this->pluginname = 'blog';
 233         }
 234         // tag page needs to set env as "tag"
 235         if ($this->env == 'tag') {
 236             $this->plugintype = 'moodle';
 237             $this->pluginname = 'tag';
 238         }
 239         if ($this->context->contextlevel == CONTEXT_BLOCK) {
 240             if ($block = $DB->get_record('block_instances', array('id'=>$this->context->instanceid))) {
 241                 $this->plugintype = 'block';
 242                 $this->pluginname = $block->blockname;
 243             }
 244         }
 245
 246         if ($this->context->contextlevel == CONTEXT_MODULE && $this->env != 'block_comments') {
 247             $this->plugintype = 'mod';
 248             // to improve performance, pluginname should be assigned before initilise comment object
 249             // if it is empty, we will try to guess, it will rarely be used.
 250             if (empty($this->pluginname)) {
 251                 if (empty($this->course)) {
 252                     $this->course = $DB->get_record('course', array('id'=>$this->courseid), '*', MUST_EXIST);
 253                 }
 254                 $this->modinfo = get_fast_modinfo($this->course);
 255                 $this->pluginname = $this->modinfo->cms[$this->cm->id]->modname;
 256             }
 257         }
 258     }
 259
 260     /**
 261      * check posting comments permission
 262      * It will check based on user roles and ask modules
 263      * If you need to check permission by modules, a
 264      * function named $pluginname_check_comment_post must be implemented
 265      */
 266     private function check_permissions() {
 267         global $CFG;
 268         $this->postcap = has_capability('moodle/comment:post', $this->context);
 269         $this->viewcap = has_capability('moodle/comment:view', $this->context);
 270         if (!empty($this->plugintype)) {
 271             $permissions = plugin_callback($this->plugintype, $this->pluginname, FEATURE_COMMENT, 'permissions', $this->args, array('post'=>true, 'view'=>true));
 272             $this->postcap = $this->postcap && $permissions['post'];
 273             $this->viewcap = $this->viewcap && $permissions['view'];
 274         }
 275     }
 276
 277     /**
 278      * Prepare comment code in html
 279      * @param  boolean $return
 280      * @return mixed
 281      */
 282     public function output($return = true) {
 283         global $PAGE, $OUTPUT;
 284                 static $template_printed;
 285
 286         $this->link = $PAGE->url;
 287         $murl = new moodle_url($this->link);
 288         $murl->remove_params('nonjscomment');
 289         $murl->param('nonjscomment', 'true');
 290         $murl->param('comment_itemid', $this->itemid);
 291         $murl->param('comment_context', $this->context->id);
 292         $murl->param('comment_area', $this->commentarea);
 293         $murl->remove_params('comment_page');
 294         $this->link = $murl->out();
 295
 296         $options = new stdclass;
 297         $options->client_id = $this->cid;
 298         $options->commentarea = $this->commentarea;
 299         $options->itemid = $this->itemid;
 300         $options->page   = 0;
 301         $options->courseid = $this->courseid;
 302         $options->contextid = $this->contextid;
 303         $options->env = $this->env;
 304         if ($this->env == 'block_comments') {
 305             $options->autostart = true;
 306             $options->notoggle = true;
 307         }
 308
 309         $PAGE->requires->js_init_call('M.core_comment.init', array($options), true);
 310
 311         if (!empty(self::$nonjs)) {
 312             // return non js comments interface
 313             return $this->print_comments(self::$comment_page, $return, true);
 314         }
 315
 316         $strsubmit = get_string('savecomment');
 317         $strcancel = get_string('cancel');
 318         $sesskey = sesskey();
 319         $html = '';
 320         // print html template
 321         // Javascript will use the template to render new comments
 322         if (empty($template_printed) && !empty($this->viewcap)) {
 323             $html .= '<div style="display:none" id="cmt-tmpl">' . $this->template . '</div>';
 324             $template_printed = true;
 325         }
 326
 327         if (!empty($this->viewcap)) {
 328             // print commenting icon and tooltip
 329             $icon = $OUTPUT->pix_url('t/collapsed');
 330             $html .= <<<EOD
 331 <div class="mdl-left">
 332 <a id="comment-link-{$this->cid}" href="{$this->link}">
 333     <img id="comment-img-{$this->cid}" src="$icon" alt="{$this->linktext}" title="{$this->linktext}" />
 334     <span id="comment-link-text-{$this->cid}">{$this->linktext} {$this->count}</span>
 335 </a>
 336 <div id="comment-ctrl-{$this->cid}" class="comment-ctrl">
 337     <ul id="comment-list-{$this->cid}" class="comment-list">
 338 EOD;
 339             // in comments block, we print comments list right away
 340             if ($this->env == 'block_comments') {
 341                 $html .= $this->print_comments(0, true, false);
 342                 $html .= '</ul>';
 343                 $html .= $this->get_pagination(0);
 344             } else {
 345                 $html .= <<<EOD
 346     </ul>
 347     <div id="comment-pagination-{$this->cid}" class="comment-pagination"></div>
 348 EOD;
 349             }
 350
 351             // print posting textarea
 352             if (!empty($this->postcap)) {
 353                 $html .= <<<EOD
 354 <div class='comment-area'>
 355     <div class="bd">
 356         <textarea name="content" rows="2" id="dlg-content-{$this->cid}"></textarea>
 357     </div>
 358     <div class="fd" id="comment-action-{$this->cid}">
 359         <a href="#" id="comment-action-post-{$this->cid}"> {$strsubmit} </a>
 360 EOD;
 361         if ($this->env != 'block_comments') {
 362             $html .= <<<EOD
 363         <span> | </span>
 364         <a href="#" id="comment-action-cancel-{$this->cid}"> {$strcancel} </a>
 365 EOD;
 366         }
 367
 368         $html .= <<<EOD
 369     </div>
 370 </div>
 371 <div class="clearer"></div>
 372 EOD;
 373             }
 374
 375             $html .= <<<EOD
 376 </div><!-- end of comment-ctrl -->
 377 </div>
 378 EOD;
 379         } else {
 380             $html = '';
 381         }
 382
 383         if ($return) {
 384             return $html;
 385         } else {
 386             echo $html;
 387         }
 388     }
 389
 390     /**
 391      * Return matched comments
 392      *
 393      * @param  int $page
 394      * @return mixed
 395      */
 396     public function get_comments($page = '') {
 397         global $DB, $CFG, $USER, $OUTPUT;
 398         if (empty($this->viewcap)) {
 399             return false;
 400         }
 401         if (!is_numeric($page)) {
 402             $page = 0;
 403         }
 404         $this->page = $page;
 405         $params = array();
 406         $start = $page * $CFG->commentsperpage;
 407         $ufields = user_picture::fields('u', array('username'));
 408         $sql = "SELECT $ufields, c.id AS cid, c.content AS ccontent, c.format AS cformat, c.timecreated AS ctimecreated
 409                   FROM {comments} c
 410                   JOIN {user} u ON u.id = c.userid
 411                  WHERE c.contextid = :contextid AND c.commentarea = :commentarea AND c.itemid = :itemid
 412               ORDER BY c.timecreated DESC";
 413         $params['contextid'] = $this->contextid;
 414         $params['commentarea'] = $this->commentarea;
 415         $params['itemid'] = $this->itemid;
 416
 417         $comments = array();
 418         $candelete = has_capability('moodle/comment:delete', $this->context);
 419         $rs = $DB->get_recordset_sql($sql, $params, $start, $CFG->commentsperpage);
 420         foreach ($rs as $u) {
 421             $c = new object();
 422             $c->id          = $u->cid;
 423             $c->content     = $u->ccontent;
 424             $c->format      = $u->cformat;
 425             $c->timecreated = $u->ctimecreated;
 426             $url = new moodle_url('/user/view.php', array('id'=>$u->id, 'course'=>$this->courseid));
 427             $c->username = $u->username;
 428             $c->profileurl = $url;
 429             $c->fullname = fullname($u);
 430             $c->time = userdate($c->timecreated, get_string('strftimerecent', 'langconfig'));
 431             $c->content = format_text($c->content, $c->format);
 432
 433             $c->avatar = $OUTPUT->user_picture($u, array('size'=>18));
 434             if (($USER->id == $u->id) || !empty($candelete)) {
 435                 $c->delete = true;
 436             }
 437             $comments[] = $c;
 438         }
 439         $rs->close();
 440
 441         if (!empty($this->plugintype)) {
 442             // moodle module will filter comments
 443             $comments = plugin_callback($this->plugintype, $this->pluginname, FEATURE_COMMENT, 'display', array($comments, $this->args), $comments);
 444         }
 445
 446         return $comments;
 447     }
 448
 449     public function count() {
 450         global $DB;
 451         if ($count = $DB->count_records('comments', array('itemid'=>$this->itemid, 'commentarea'=>$this->commentarea, 'contextid'=>$this->context->id))) {
 452             return $count;
 453         } else {
 454             return 0;
 455         }
 456     }
 457
 458     public function get_pagination($page = 0) {
 459         global $DB, $CFG, $OUTPUT;
 460         $count = $this->count();
 461         $pages = (int)ceil($count/$CFG->commentsperpage);
 462         if ($pages == 1 || $pages == 0) {
 463             return '';
 464         }
 465         if (!empty(self::$nonjs)) {
 466             // used in non-js interface
 467             return $OUTPUT->paging_bar($count, $page, $CFG->commentsperpage, $this->link, 'comment_page');
 468         } else {
 469             // return ajax paging bar
 470             $str = '';
 471             $str .= '<div class="comment-paging" id="comment-pagination-'.$this->cid.'">';
 472             for ($p=0; $p<$pages; $p++) {
 473                 if ($p == $page) {
 474                     $class = 'curpage';
 475                 } else {
 476                     $class = 'pageno';
 477                 }
 478                 $str .= '<a href="#" class="'.$class.'" id="comment-page-'.$this->cid.'-'.$p.'">'.($p+1).'</a> ';
 479             }
 480             $str .= '</div>';
 481         }
 482         return $str;
 483     }
 484
 485     /**
 486      * Add a new comment
 487      * @param string $content
 488      * @return mixed
 489      */
 490     public function add($content, $format = FORMAT_MOODLE) {
 491         global $CFG, $DB, $USER, $OUTPUT;
 492         if (empty($this->postcap)) {
 493             throw new comment_exception('nopermissiontocomment');
 494         }
 495         $now = time();
 496         $newcmt = new stdclass;
 497         $newcmt->contextid    = $this->contextid;
 498         $newcmt->commentarea  = $this->commentarea;
 499         $newcmt->itemid       = $this->itemid;
 500         $newcmt->content      = $content;
 501         $newcmt->format       = $format;
 502         $newcmt->userid       = $USER->id;
 503         $newcmt->timecreated  = $now;
 504
 505         if (!empty($this->plugintype)) {
 506             // moodle module will check content
 507             $ret = plugin_callback($this->plugintype, $this->pluginname, FEATURE_COMMENT, 'add', array(&$newcmt, $this->args), true);
 508             if (!$ret) {
 509                 throw new comment_exception('modulererejectcomment');
 510             }
 511         }
 512
 513         $cmt_id = $DB->insert_record('comments', $newcmt);
 514         if (!empty($cmt_id)) {
 515             $newcmt->id = $cmt_id;
 516             $newcmt->time = userdate($now, get_string('strftimerecent', 'langconfig'));
 517             $newcmt->username = $USER->username;
 518             $newcmt->fullname = fullname($USER);
 519             $url = new moodle_url('/user/view.php', array('id'=>$USER->id, 'course'=>$this->courseid));
 520             $newcmt->profileurl = $url->out();
 521             $newcmt->content = format_text($newcmt->content);
 522             $newcmt->avatar = $OUTPUT->user_picture($USER, array('size'=>16));
 523             return $newcmt;
 524         } else {
 525             throw new comment_exception('dbupdatefailed');
 526         }
 527     }
 528
 529     /**
 530      * delete by context, commentarea and itemid
 531      *
 532      */
 533     public function delete_comments() {
 534         global $DB;
 535         $DB->delete_records('comments', array(
 536             'contextid'=>$this->context->id,
 537             'commentarea'=>$this->commentarea,
 538             'itemid'=>$this->itemid)
 539         );
 540         return true;
 541     }
 542
 543     /**
 544      * Delete a comment
 545      * @param  int $commentid
 546      * @return mixed
 547      */
 548     public function delete($commentid) {
 549         global $DB, $USER;
 550         $candelete = has_capability('moodle/comment:delete', $this->context);
 551         if (!$comment = $DB->get_record('comments', array('id'=>$commentid))) {
 552             throw new comment_exception('dbupdatefailed');
 553         }
 554         if (!($USER->id == $comment->userid || !empty($candelete))) {
 555             throw new comment_exception('nopermissiontocomment');
 556         }
 557         $DB->delete_records('comments', array('id'=>$commentid));
 558         return true;
 559     }
 560
 561     /**
 562      * Print comments
 563      * @param int $page
 564      * @param boolean $return return comments list string or print it out
 565      * @param boolean $nonjs print nonjs comments list or not?
 566      * @return mixed
 567      */
 568     public function print_comments($page = 0, $return = true, $nonjs = true) {
 569         global $DB, $CFG, $PAGE;
 570         $html = '';
 571         if (!(self::$comment_itemid == $this->itemid &&
 572             self::$comment_context == $this->context->id &&
 573             self::$comment_area == $this->commentarea)) {
 574             $page = 0;
 575         }
 576         $comments = $this->get_comments($page);
 577
 578         $html = '';
 579         if ($nonjs) {
 580             $html .= '<h3>'.get_string('comments').'</h3>';
 581             $html .= "<ul id='comment-list-$this->cid' class='comment-list'>";
 582         }
 583         $results = array();
 584         $list = '';
 585
 586         foreach ($comments as $cmt) {
 587             $list = '<li id="comment-'.$cmt->id.'-'.$this->cid.'">'.$this->print_comment($cmt, $nonjs).'</li>' . $list;
 588         }
 589         $html .= $list;
 590         if ($nonjs) {
 591             $html .= '</ul>';
 592             $html .= $this->get_pagination($page);
 593         }
 594         $sesskey = sesskey();
 595         $returnurl = $PAGE->url;
 596         $strsubmit = get_string('submit');
 597         if ($nonjs) {
 598         $html .= <<<EOD
 599 <form method="POST" action="{$CFG->wwwroot}/comment/comment_post.php">
 600 <textarea name="content" rows="2"></textarea>
 601 <input type="hidden" name="contextid" value="$this->contextid" />
 602 <input type="hidden" name="action" value="add" />
 603 <input type="hidden" name="area" value="$this->commentarea" />
 604 <input type="hidden" name="itemid" value="$this->itemid" />
 605 <input type="hidden" name="courseid" value="{$this->courseid}" />
 606 <input type="hidden" name="sesskey" value="{$sesskey}" />
 607 <input type="hidden" name="returnurl" value="{$returnurl}" />
 608 <input type="submit" value="{$strsubmit}" />
 609 </form>
 610 EOD;
 611         }
 612         if ($return) {
 613             return $html;
 614         } else {
 615             echo $html;
 616         }
 617     }
 618
 619     public function print_comment($cmt, $nonjs = true) {
 620         global $OUTPUT;
 621         $patterns = array();
 622         $replacements = array();
 623
 624         if (!empty($cmt->delete) && empty($nonjs)) {
 625             $cmt->content = '<div class="comment-delete"><a href="#" id ="comment-delete-'.$this->cid.'-'.$cmt->id.'"><img src="'.$OUTPUT->pix_url('t/delete').'" /></a></div>' . $cmt->content;
 626             // add the button
 627         }
 628         $patterns[] = '___picture___';
 629         $patterns[] = '___name___';
 630         $patterns[] = '___content___';
 631         $patterns[] = '___time___';
 632         $replacements[] = $cmt->avatar;
 633         $replacements[] = html_writer::link($cmt->profileurl, $cmt->fullname);
 634         $replacements[] = $cmt->content;
 635         $replacements[] = userdate($cmt->timecreated, get_string('strftimerecent', 'langconfig'));
 636
 637         // use html template to format a single comment.
 638         return str_replace($patterns, $replacements, $this->template);
 639     }
 640 }
 641
 642 class comment_exception extends moodle_exception {
 643     public $message;
 644     function __construct($errorcode) {
 645         $this->errorcode = $errorcode;
 646         $this->message = get_string($errorcode, 'error');
 647     }
 648 }