comment/lib.php

   1 <?php
   2 // This file is part of Moodle - http://moodle.org/
   3 //
   4 // Moodle is free software: you can redistribute it and/or modify
   5 // it under the terms of the GNU General Public License as published by
   6 // the Free Software Foundation, either version 3 of the License, or
   7 // (at your option) any later version.
   8 //
   9 // Moodle is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13 //
  14 // You should have received a copy of the GNU General Public License
  15 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  16
  17 /**
  18  * Functions and classes for commenting
  19  *
  20  * @package   core
  21  * @copyright 2010 Dongsheng Cai {@link http://dongsheng.org}
  22  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  23  */
  24 defined('MOODLE_INTERNAL') || die();
  25
  26 /**
  27  * Comment is helper class to add/delete comments anywhere in moodle
  28  *
  29  * @package   core
  30  * @category  comment
  31  * @copyright 2010 Dongsheng Cai {@link http://dongsheng.org}
  32  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  33  */
  34 class comment {
  35     /** @var int there may be several comment box in one page so we need a client_id to recognize them */
  36     private $cid;
  37     /** @var string commentarea is used to specify different parts shared the same itemid */
  38     private $commentarea;
  39     /** @var int itemid is used to associate with commenting content */
  40     private $itemid;
  41     /** @var string this html snippet will be used as a template to build comment content */
  42     private $template;
  43     /** @var int The context id for comments */
  44     private $contextid;
  45     /** @var stdClass The context itself */
  46     private $context;
  47     /** @var int The course id for comments */
  48     private $courseid;
  49     /** @var stdClass course module object, only be used to help find pluginname automatically */
  50     private $cm;
  51     /**
  52      * The component that this comment is for.
  53      *
  54      * It is STRONGLY recommended to set this.
  55      * Added as a database field in 2.9, old comments will have a null component.
  56      *
  57      * @var string
  58      */
  59     private $component;
  60     /** @var string This is calculated by normalising the component */
  61     private $pluginname;
  62     /** @var string This is calculated by normalising the component */
  63     private $plugintype;
  64     /** @var bool Whether the user has the required capabilities/permissions to view comments. */
  65     private $viewcap = false;
  66     /** @var bool Whether the user has the required capabilities/permissions to post comments. */
  67     private $postcap = false;
  68     /** @var string to customize link text */
  69     private $linktext;
  70     /** @var bool If set to true then comment sections won't be able to be opened and closed instead they will always be visible. */
  71     protected $notoggle = false;
  72     /** @var bool If set to true comments are automatically loaded as soon as the page loads. */
  73     protected $autostart = false;
  74     /** @var bool If set to true the total count of comments is displayed when displaying comments. */
  75     protected $displaytotalcount = false;
  76     /** @var bool If set to true a cancel button will be shown on the form used to submit comments. */
  77     protected $displaycancel = false;
  78     /** @var int The number of comments associated with this comments params */
  79     protected $totalcommentcount = null;
  80
  81     /**
  82      * Set to true to remove the col attribute from the textarea making it full width.
  83      * @var bool
  84      */
  85     protected $fullwidth = false;
  86
  87     /** @var bool Use non-javascript UI */
  88     private static $nonjs = false;
  89     /** @var int comment itemid used in non-javascript UI */
  90     private static $comment_itemid = null;
  91     /** @var int comment context used in non-javascript UI */
  92     private static $comment_context = null;
  93     /** @var string comment area used in non-javascript UI */
  94     private static $comment_area = null;
  95     /** @var string comment page used in non-javascript UI */
  96     private static $comment_page = null;
  97     /** @var string comment itemid component in non-javascript UI */
  98     private static $comment_component = null;
  99
 100     /**
 101      * Construct function of comment class, initialise
 102      * class members
 103      *
 104      * @param stdClass $options {
 105      *            context => context context to use for the comment [required]
 106      *            component => string which plugin will comment being added to [required]
 107      *            itemid  => int the id of the associated item (forum post, glossary item etc) [required]
 108      *            area    => string comment area
 109      *            cm      => stdClass course module
 110      *            course  => course course object
 111      *            client_id => string an unique id to identify comment area
 112      *            autostart => boolean automatically expend comments
 113      *            showcount => boolean display the number of comments
 114      *            displaycancel => boolean display cancel button
 115      *            notoggle => boolean don't show/hide button
 116      *            linktext => string title of show/hide button
 117      * }
 118      */
 119     public function __construct(stdClass $options) {
 120         $this->viewcap = false;
 121         $this->postcap = false;
 122
 123         // setup client_id
 124         if (!empty($options->client_id)) {
 125             $this->cid = $options->client_id;
 126         } else {
 127             $this->cid = uniqid();
 128         }
 129
 130         // setup context
 131         if (!empty($options->context)) {
 132             $this->context = $options->context;
 133             $this->contextid = $this->context->id;
 134         } else if(!empty($options->contextid)) {
 135             $this->contextid = $options->contextid;
 136             $this->context = context::instance_by_id($this->contextid);
 137         } else {
 138             print_error('invalidcontext');
 139         }
 140
 141         if (!empty($options->component)) {
 142             // set and validate component
 143             $this->set_component($options->component);
 144         } else {
 145             // component cannot be empty
 146             throw new comment_exception('invalidcomponent');
 147         }
 148
 149         // setup course
 150         // course will be used to generate user profile link
 151         if (!empty($options->course)) {
 152             $this->courseid = $options->course->id;
 153         } else if (!empty($options->courseid)) {
 154             $this->courseid = $options->courseid;
 155         } else {
 156             if ($coursecontext = $this->context->get_course_context(false)) {
 157                 $this->courseid = $coursecontext->instanceid;
 158             } else {
 159                 $this->courseid = SITEID;
 160             }
 161         }
 162
 163         // setup coursemodule
 164         if (!empty($options->cm)) {
 165             $this->cm = $options->cm;
 166         } else {
 167             $this->cm = null;
 168         }
 169
 170         // setup commentarea
 171         if (!empty($options->area)) {
 172             $this->commentarea = $options->area;
 173         }
 174
 175         // setup itemid
 176         if (!empty($options->itemid)) {
 177             $this->itemid = $options->itemid;
 178         } else {
 179             $this->itemid = 0;
 180         }
 181
 182         // setup customized linktext
 183         if (!empty($options->linktext)) {
 184             $this->linktext = $options->linktext;
 185         } else {
 186             $this->linktext = get_string('comments');
 187         }
 188
 189         // setup options for callback functions
 190         $this->comment_param = new stdClass();
 191         $this->comment_param->context     = $this->context;
 192         $this->comment_param->courseid    = $this->courseid;
 193         $this->comment_param->cm          = $this->cm;
 194         $this->comment_param->commentarea = $this->commentarea;
 195         $this->comment_param->itemid      = $this->itemid;
 196
 197         // setup notoggle
 198         if (!empty($options->notoggle)) {
 199             $this->set_notoggle($options->notoggle);
 200         }
 201
 202         // setup notoggle
 203         if (!empty($options->autostart)) {
 204             $this->set_autostart($options->autostart);
 205         }
 206
 207         // setup displaycancel
 208         if (!empty($options->displaycancel)) {
 209             $this->set_displaycancel($options->displaycancel);
 210         }
 211
 212         // setup displaytotalcount
 213         if (!empty($options->showcount)) {
 214             $this->set_displaytotalcount($options->showcount);
 215         }
 216
 217         // setting post and view permissions
 218         $this->check_permissions();
 219
 220         // load template
 221         $this->template = html_writer::start_tag('div', array('class' => 'comment-message'));
 222
 223         $this->template .= html_writer::start_tag('div', array('class' => 'comment-message-meta m-r-3'));
 224
 225         $this->template .= html_writer::tag('span', '___picture___', array('class' => 'picture'));
 226         $this->template .= html_writer::tag('span', '___name___', array('class' => 'user')) . ' - ';
 227         $this->template .= html_writer::tag('span', '___time___', array('class' => 'time'));
 228
 229         $this->template .= html_writer::end_tag('div'); // .comment-message-meta
 230         $this->template .= html_writer::tag('div', '___content___', array('class' => 'text'));
 231
 232         $this->template .= html_writer::end_tag('div'); // .comment-message
 233
 234         if (!empty($this->plugintype)) {
 235             $this->template = plugin_callback($this->plugintype, $this->pluginname, 'comment', 'template', array($this->comment_param), $this->template);
 236         }
 237
 238         unset($options);
 239     }
 240
 241     /**
 242      * Receive nonjs comment parameters
 243      *
 244      * @param moodle_page $page The page object to initialise comments within
 245      *                          If not provided the global $PAGE is used
 246      */
 247     public static function init(moodle_page $page = null) {
 248         global $PAGE;
 249
 250         if (empty($page)) {
 251             $page = $PAGE;
 252         }
 253         // setup variables for non-js interface
 254         self::$nonjs = optional_param('nonjscomment', '', PARAM_ALPHANUM);
 255         self::$comment_itemid = optional_param('comment_itemid',  '', PARAM_INT);
 256         self::$comment_component = optional_param('comment_component', '', PARAM_COMPONENT);
 257         self::$comment_context = optional_param('comment_context', '', PARAM_INT);
 258         self::$comment_page = optional_param('comment_page',    '', PARAM_INT);
 259         self::$comment_area = optional_param('comment_area',    '', PARAM_AREA);
 260
 261         $page->requires->strings_for_js(array(
 262                 'addcomment',
 263                 'comments',
 264                 'commentscount',
 265                 'commentsrequirelogin',
 266                 'deletecommentbyon'
 267             ),
 268             'moodle'
 269         );
 270     }
 271
 272     /**
 273      * Sets the component.
 274      *
 275      * This method shouldn't be public, changing the component once it has been set potentially
 276      * invalidates permission checks.
 277      * A coding_error is now thrown if code attempts to change the component.
 278      *
 279      * @throws coding_exception if you try to change the component after it has been set.
 280      * @param string $component
 281      */
 282     public function set_component($component) {
 283         if (!empty($this->component) && $this->component !== $component) {
 284             throw new coding_exception('You cannot change the component of a comment once it has been set');
 285         }
 286         $this->component = $component;
 287         list($this->plugintype, $this->pluginname) = core_component::normalize_component($component);
 288     }
 289
 290     /**
 291      * Determines if the user can view the comment.
 292      *
 293      * @param bool $value
 294      */
 295     public function set_view_permission($value) {
 296         $this->viewcap = (bool)$value;
 297     }
 298
 299     /**
 300      * Determines if the user can post a comment
 301      *
 302      * @param bool $value
 303      */
 304     public function set_post_permission($value) {
 305         $this->postcap = (bool)$value;
 306     }
 307
 308     /**
 309      * check posting comments permission
 310      * It will check based on user roles and ask modules
 311      * If you need to check permission by modules, a
 312      * function named $pluginname_check_comment_post must be implemented
 313      */
 314     private function check_permissions() {
 315         $this->postcap = has_capability('moodle/comment:post', $this->context);
 316         $this->viewcap = has_capability('moodle/comment:view', $this->context);
 317         if (!empty($this->plugintype)) {
 318             $permissions = plugin_callback($this->plugintype, $this->pluginname, 'comment', 'permissions', array($this->comment_param), array('post'=>false, 'view'=>false));
 319             $this->postcap = $this->postcap && $permissions['post'];
 320             $this->viewcap = $this->viewcap && $permissions['view'];
 321         }
 322     }
 323
 324     /**
 325      * Gets a link for this page that will work with JS disabled.
 326      *
 327      * @global moodle_page $PAGE
 328      * @param moodle_page $page
 329      * @return moodle_url
 330      */
 331     public function get_nojslink(moodle_page $page = null) {
 332         if ($page === null) {
 333             global $PAGE;
 334             $page = $PAGE;
 335         }
 336
 337         $link = new moodle_url($page->url, array(
 338             'nonjscomment'    => true,
 339             'comment_itemid'  => $this->itemid,
 340             'comment_context' => $this->context->id,
 341             'comment_component' => $this->get_component(),
 342             'comment_area'    => $this->commentarea,
 343         ));
 344         $link->remove_params(array('comment_page'));
 345         return $link;
 346     }
 347
 348     /**
 349      * Sets the value of the notoggle option.
 350      *
 351      * If set to true then the user will not be able to expand and collase
 352      * the comment section.
 353      *
 354      * @param bool $newvalue
 355      */
 356     public function set_notoggle($newvalue = true) {
 357         $this->notoggle = (bool)$newvalue;
 358     }
 359
 360     /**
 361      * Sets the value of the autostart option.
 362      *
 363      * If set to true then the comments will be loaded during page load.
 364      * Normally this happens only once the user expands the comment section.
 365      *
 366      * @param bool $newvalue
 367      */
 368     public function set_autostart($newvalue = true) {
 369         $this->autostart = (bool)$newvalue;
 370     }
 371
 372     /**
 373      * Sets the displaycancel option
 374      *
 375      * If set to true then a cancel button will be shown when using the form
 376      * to post comments.
 377      *
 378      * @param bool $newvalue
 379      */
 380     public function set_displaycancel($newvalue = true) {
 381         $this->displaycancel = (bool)$newvalue;
 382     }
 383
 384     /**
 385      * Sets the displaytotalcount option
 386      *
 387      * If set to true then the total number of comments will be displayed
 388      * when printing comments.
 389      *
 390      * @param bool $newvalue
 391      */
 392     public function set_displaytotalcount($newvalue = true) {
 393         $this->displaytotalcount = (bool)$newvalue;
 394     }
 395
 396     /**
 397      * Initialises the JavaScript that enchances the comment API.
 398      *
 399      * @param moodle_page $page The moodle page object that the JavaScript should be
 400      *                          initialised for.
 401      */
 402     public function initialise_javascript(moodle_page $page) {
 403
 404         $options = new stdClass;
 405         $options->client_id   = $this->cid;
 406         $options->commentarea = $this->commentarea;
 407         $options->itemid      = $this->itemid;
 408         $options->page        = 0;
 409         $options->courseid    = $this->courseid;
 410         $options->contextid   = $this->contextid;
 411         $options->component   = $this->component;
 412         $options->notoggle    = $this->notoggle;
 413         $options->autostart   = $this->autostart;
 414
 415         $page->requires->js_init_call('M.core_comment.init', array($options), true);
 416
 417         return true;
 418     }
 419
 420     /**
 421      * Prepare comment code in html
 422      * @param  boolean $return
 423      * @return string|void
 424      */
 425     public function output($return = true) {
 426         global $PAGE, $OUTPUT;
 427         static $template_printed;
 428
 429         $this->initialise_javascript($PAGE);
 430
 431         if (!empty(self::$nonjs)) {
 432             // return non js comments interface
 433             return $this->print_comments(self::$comment_page, $return, true);
 434         }
 435
 436         $html = '';
 437
 438         // print html template
 439         // Javascript will use the template to render new comments
 440         if (empty($template_printed) && $this->can_view()) {
 441             $html .= html_writer::tag('div', $this->template, array('style' => 'display:none', 'id' => 'cmt-tmpl'));
 442             $template_printed = true;
 443         }
 444
 445         if ($this->can_view()) {
 446             // print commenting icon and tooltip
 447             $html .= html_writer::start_tag('div', array('class' => 'mdl-left'));
 448             $html .= html_writer::link($this->get_nojslink($PAGE), get_string('showcommentsnonjs'), array('class' => 'showcommentsnonjs'));
 449
 450             if (!$this->notoggle) {
 451                 // If toggling is enabled (notoggle=false) then print the controls to toggle
 452                 // comments open and closed
 453                 $countstring = '';
 454                 if ($this->displaytotalcount) {
 455                     $countstring = '('.$this->count().')';
 456                 }
 457                 $collapsedimage= 't/collapsed';
 458                 if (right_to_left()) {
 459                     $collapsedimage= 't/collapsed_rtl';
 460                 } else {
 461                     $collapsedimage= 't/collapsed';
 462                 }
 463                 $html .= html_writer::start_tag('a', array(
 464                     'class' => 'comment-link',
 465                     'id' => 'comment-link-'.$this->cid,
 466                     'href' => '#',
 467                     'role' => 'button',
 468                     'aria-expanded' => 'false')
 469                 );
 470                 $html .= $OUTPUT->pix_icon($collapsedimage, $this->linktext);
 471                 $html .= html_writer::tag('span', $this->linktext.' '.$countstring, array('id' => 'comment-link-text-'.$this->cid));
 472                 $html .= html_writer::end_tag('a');
 473             }
 474
 475             $html .= html_writer::start_tag('div', array('id' => 'comment-ctrl-'.$this->cid, 'class' => 'comment-ctrl'));
 476
 477             if ($this->autostart) {
 478                 // If autostart has been enabled print the comments list immediatly
 479                 $html .= html_writer::start_tag('ul', array('id' => 'comment-list-'.$this->cid, 'class' => 'comment-list comments-loaded'));
 480                 $html .= html_writer::tag('li', '', array('class' => 'first'));
 481                 $html .= $this->print_comments(0, true, false);
 482                 $html .= html_writer::end_tag('ul'); // .comment-list
 483                 $html .= $this->get_pagination(0);
 484             } else {
 485                 $html .= html_writer::start_tag('ul', array('id' => 'comment-list-'.$this->cid, 'class' => 'comment-list'));
 486                 $html .= html_writer::tag('li', '', array('class' => 'first'));
 487                 $html .= html_writer::end_tag('ul'); // .comment-list
 488                 $html .= html_writer::tag('div', '', array('id' => 'comment-pagination-'.$this->cid, 'class' => 'comment-pagination'));
 489             }
 490
 491             if ($this->can_post()) {
 492                 // print posting textarea
 493                 $textareaattrs = array(
 494                     'name' => 'content',
 495                     'rows' => 2,
 496                     'id' => 'dlg-content-'.$this->cid
 497                 );
 498                 if (!$this->fullwidth) {
 499                     $textareaattrs['cols'] = '20';
 500                 } else {
 501                     $textareaattrs['class'] = 'fullwidth';
 502                 }
 503
 504                 $html .= html_writer::start_tag('div', array('class' => 'comment-area'));
 505                 $html .= html_writer::start_tag('div', array('class' => 'db'));
 506                 $html .= html_writer::tag('textarea', '', $textareaattrs);
 507                 $html .= html_writer::end_tag('div'); // .db
 508
 509                 $html .= html_writer::start_tag('div', array('class' => 'fd', 'id' => 'comment-action-'.$this->cid));
 510                 $html .= html_writer::link('#', get_string('savecomment'), array('id' => 'comment-action-post-'.$this->cid));
 511
 512                 if ($this->displaycancel) {
 513                     $html .= html_writer::tag('span', ' | ');
 514                     $html .= html_writer::link('#', get_string('cancel'), array('id' => 'comment-action-cancel-'.$this->cid));
 515                 }
 516
 517                 $html .= html_writer::end_tag('div'); // .fd
 518                 $html .= html_writer::end_tag('div'); // .comment-area
 519                 $html .= html_writer::tag('div', '', array('class' => 'clearer'));
 520             }
 521
 522             $html .= html_writer::end_tag('div'); // .comment-ctrl
 523             $html .= html_writer::end_tag('div'); // .mdl-left
 524         } else {
 525             $html = '';
 526         }
 527
 528         if ($return) {
 529             return $html;
 530         } else {
 531             echo $html;
 532         }
 533     }
 534
 535     /**
 536      * Return matched comments
 537      *
 538      * @param  int $page
 539      * @return array
 540      */
 541     public function get_comments($page = '') {
 542         global $DB, $CFG, $USER, $OUTPUT;
 543         if (!$this->can_view()) {
 544             return false;
 545         }
 546         if (!is_numeric($page)) {
 547             $page = 0;
 548         }
 549         $params = array();
 550         $perpage = (!empty($CFG->commentsperpage))?$CFG->commentsperpage:15;
 551         $start = $page * $perpage;
 552         $ufields = user_picture::fields('u');
 553
 554         list($componentwhere, $component) = $this->get_component_select_sql('c');
 555         if ($component) {
 556             $params['component'] = $component;
 557         }
 558
 559         $sql = "SELECT $ufields, c.id AS cid, c.content AS ccontent, c.format AS cformat, c.timecreated AS ctimecreated
 560                   FROM {comments} c
 561                   JOIN {user} u ON u.id = c.userid
 562                  WHERE c.contextid = :contextid AND
 563                        c.commentarea = :commentarea AND
 564                        c.itemid = :itemid AND
 565                        $componentwhere
 566               ORDER BY c.timecreated DESC";
 567         $params['contextid'] = $this->contextid;
 568         $params['commentarea'] = $this->commentarea;
 569         $params['itemid'] = $this->itemid;
 570
 571         $comments = array();
 572         $formatoptions = array('overflowdiv' => true);
 573         $rs = $DB->get_recordset_sql($sql, $params, $start, $perpage);
 574         foreach ($rs as $u) {
 575             $c = new stdClass();
 576             $c->id          = $u->cid;
 577             $c->content     = $u->ccontent;
 578             $c->format      = $u->cformat;
 579             $c->timecreated = $u->ctimecreated;
 580             $c->strftimeformat = get_string('strftimerecent', 'langconfig');
 581             $url = new moodle_url('/user/view.php', array('id'=>$u->id, 'course'=>$this->courseid));
 582             $c->profileurl = $url->out(false); // URL should not be escaped just yet.
 583             $c->fullname = fullname($u);
 584             $c->time = userdate($c->timecreated, $c->strftimeformat);
 585             $c->content = format_text($c->content, $c->format, $formatoptions);
 586             $c->avatar = $OUTPUT->user_picture($u, array('size'=>18));
 587             $c->userid = $u->id;
 588
 589             $candelete = $this->can_delete($c->id);
 590             if (($USER->id == $u->id) || !empty($candelete)) {
 591                 $c->delete = true;
 592             }
 593             $comments[] = $c;
 594         }
 595         $rs->close();
 596
 597         if (!empty($this->plugintype)) {
 598             // moodle module will filter comments
 599             $comments = plugin_callback($this->plugintype, $this->pluginname, 'comment', 'display', array($comments, $this->comment_param), $comments);
 600         }
 601
 602         return $comments;
 603     }
 604
 605     /**
 606      * Returns an SQL fragment and param for selecting on component.
 607      * @param string $alias
 608      * @return array
 609      */
 610     protected function get_component_select_sql($alias = '') {
 611         $component = $this->get_component();
 612         if ($alias) {
 613             $alias = $alias.'.';
 614         }
 615         if (empty($component)) {
 616             $componentwhere = "{$alias}component IS NULL";
 617             $component = null;
 618         } else {
 619             $componentwhere = "({$alias}component IS NULL OR {$alias}component = :component)";
 620         }
 621         return array($componentwhere, $component);
 622     }
 623
 624     /**
 625      * Returns the number of comments associated with the details of this object
 626      *
 627      * @global moodle_database $DB
 628      * @return int
 629      */
 630     public function count() {
 631         global $DB;
 632         if ($this->totalcommentcount === null) {
 633             list($where, $component) = $this->get_component_select_sql();
 634             $where .= ' AND itemid = :itemid AND commentarea = :commentarea AND contextid = :contextid';
 635             $params = array(
 636                 'itemid' => $this->itemid,
 637                 'commentarea' => $this->commentarea,
 638                 'contextid' => $this->context->id,
 639             );
 640             if ($component) {
 641                 $params['component'] = $component;
 642             }
 643
 644             $this->totalcommentcount = $DB->count_records_select('comments', $where, $params);
 645         }
 646         return $this->totalcommentcount;
 647     }
 648
 649     /**
 650      * Returns HTML to display a pagination bar
 651      *
 652      * @global stdClass $CFG
 653      * @global core_renderer $OUTPUT
 654      * @param int $page
 655      * @return string
 656      */
 657     public function get_pagination($page = 0) {
 658         global $CFG, $OUTPUT;
 659         $count = $this->count();
 660         $perpage = (!empty($CFG->commentsperpage))?$CFG->commentsperpage:15;
 661         $pages = (int)ceil($count/$perpage);
 662         if ($pages == 1 || $pages == 0) {
 663             return html_writer::tag('div', '', array('id' => 'comment-pagination-'.$this->cid, 'class' => 'comment-pagination'));
 664         }
 665         if (!empty(self::$nonjs)) {
 666             // used in non-js interface
 667             return $OUTPUT->paging_bar($count, $page, $perpage, $this->get_nojslink(), 'comment_page');
 668         } else {
 669             // return ajax paging bar
 670             $str = '';
 671             $str .= '<div class="comment-paging" id="comment-pagination-'.$this->cid.'">';
 672             for ($p=0; $p<$pages; $p++) {
 673                 if ($p == $page) {
 674                     $class = 'curpage';
 675                 } else {
 676                     $class = 'pageno';
 677                 }
 678                 $str .= '<a href="#" class="'.$class.'" id="comment-page-'.$this->cid.'-'.$p.'">'.($p+1).'</a> ';
 679             }
 680             $str .= '</div>';
 681         }
 682         return $str;
 683     }
 684
 685     /**
 686      * Add a new comment
 687      *
 688      * @global moodle_database $DB
 689      * @param string $content
 690      * @param int $format
 691      * @return stdClass
 692      */
 693     public function add($content, $format = FORMAT_MOODLE) {
 694         global $CFG, $DB, $USER, $OUTPUT;
 695         if (!$this->can_post()) {
 696             throw new comment_exception('nopermissiontocomment');
 697         }
 698         $now = time();
 699         $newcmt = new stdClass;
 700         $newcmt->contextid    = $this->contextid;
 701         $newcmt->commentarea  = $this->commentarea;
 702         $newcmt->itemid       = $this->itemid;
 703         $newcmt->component    = !empty($this->component) ? $this->component : null;
 704         $newcmt->content      = $content;
 705         $newcmt->format       = $format;
 706         $newcmt->userid       = $USER->id;
 707         $newcmt->timecreated  = $now;
 708
 709         // This callback allow module to modify the content of comment, such as filter or replacement
 710         plugin_callback($this->plugintype, $this->pluginname, 'comment', 'add', array(&$newcmt, $this->comment_param));
 711
 712         $cmt_id = $DB->insert_record('comments', $newcmt);
 713         if (!empty($cmt_id)) {
 714             $newcmt->id = $cmt_id;
 715             $newcmt->strftimeformat = get_string('strftimerecent', 'langconfig');
 716             $newcmt->fullname = fullname($USER);
 717             $url = new moodle_url('/user/view.php', array('id' => $USER->id, 'course' => $this->courseid));
 718             $newcmt->profileurl = $url->out();
 719             $newcmt->content = format_text($newcmt->content, $newcmt->format, array('overflowdiv'=>true));
 720             $newcmt->avatar = $OUTPUT->user_picture($USER, array('size'=>16));
 721
 722             $commentlist = array($newcmt);
 723
 724             if (!empty($this->plugintype)) {
 725                 // Call the display callback to allow the plugin to format the newly added comment.
 726                 $commentlist = plugin_callback($this->plugintype,
 727                                                $this->pluginname,
 728                                                'comment',
 729                                                'display',
 730                                                array($commentlist, $this->comment_param),
 731                                                $commentlist);
 732                 $newcmt = $commentlist[0];
 733             }
 734             $newcmt->time = userdate($newcmt->timecreated, $newcmt->strftimeformat);
 735
 736             // Trigger comment created event.
 737             if (core_component::is_core_subsystem($this->component)) {
 738                 $eventclassname = '\\core\\event\\' . $this->component . '_comment_created';
 739             } else {
 740                 $eventclassname = '\\' . $this->component . '\\event\comment_created';
 741             }
 742             if (class_exists($eventclassname)) {
 743                 $event = $eventclassname::create(
 744                         array(
 745                             'context' => $this->context,
 746                             'objectid' => $newcmt->id,
 747                             'other' => array(
 748                                 'itemid' => $this->itemid
 749                                 )
 750                             ));
 751                 $event->trigger();
 752             }
 753
 754             return $newcmt;
 755         } else {
 756             throw new comment_exception('dbupdatefailed');
 757         }
 758     }
 759
 760     /**
 761      * delete by context, commentarea and itemid
 762      * @param stdClass|array $param {
 763      *            contextid => int the context in which the comments exist [required]
 764      *            commentarea => string the comment area [optional]
 765      *            itemid => int comment itemid [optional]
 766      * }
 767      * @return boolean
 768      */
 769     public static function delete_comments($param) {
 770         global $DB;
 771         $param = (array)$param;
 772         if (empty($param['contextid'])) {
 773             return false;
 774         }
 775         $DB->delete_records('comments', $param);
 776         return true;
 777     }
 778
 779     /**
 780      * Delete page_comments in whole course, used by course reset
 781      *
 782      * @param stdClass $context course context
 783      */
 784     public static function reset_course_page_comments($context) {
 785         global $DB;
 786         $contexts = array();
 787         $contexts[] = $context->id;
 788         $children = $context->get_child_contexts();
 789         foreach ($children as $c) {
 790             $contexts[] = $c->id;
 791         }
 792         list($ids, $params) = $DB->get_in_or_equal($contexts);
 793         $DB->delete_records_select('comments', "commentarea='page_comments' AND contextid $ids", $params);
 794     }
 795
 796     /**
 797      * Delete a comment
 798      *
 799      * @param  int $commentid
 800      * @return bool
 801      */
 802     public function delete($commentid) {
 803         global $DB, $USER;
 804         $candelete = has_capability('moodle/comment:delete', $this->context);
 805         if (!$comment = $DB->get_record('comments', array('id'=>$commentid))) {
 806             throw new comment_exception('dbupdatefailed');
 807         }
 808         if (!($USER->id == $comment->userid || !empty($candelete))) {
 809             throw new comment_exception('nopermissiontocomment');
 810         }
 811         $DB->delete_records('comments', array('id'=>$commentid));
 812         // Trigger comment delete event.
 813         if (core_component::is_core_subsystem($this->component)) {
 814             $eventclassname = '\\core\\event\\' . $this->component . '_comment_deleted';
 815         } else {
 816             $eventclassname = '\\' . $this->component . '\\event\comment_deleted';
 817         }
 818         if (class_exists($eventclassname)) {
 819             $event = $eventclassname::create(
 820                     array(
 821                         'context' => $this->context,
 822                         'objectid' => $commentid,
 823                         'other' => array(
 824                             'itemid' => $this->itemid
 825                             )
 826                         ));
 827             $event->add_record_snapshot('comments', $comment);
 828             $event->trigger();
 829         }
 830         return true;
 831     }
 832
 833     /**
 834      * Print comments
 835      *
 836      * @param int $page
 837      * @param bool $return return comments list string or print it out
 838      * @param bool $nonjs print nonjs comments list or not?
 839      * @return string|void
 840      */
 841     public function print_comments($page = 0, $return = true, $nonjs = true) {
 842         global $DB, $CFG, $PAGE;
 843
 844         if (!$this->can_view()) {
 845             return '';
 846         }
 847
 848         if (!(self::$comment_itemid == $this->itemid &&
 849             self::$comment_context == $this->context->id &&
 850             self::$comment_area == $this->commentarea &&
 851             self::$comment_component == $this->component
 852         )) {
 853             $page = 0;
 854         }
 855         $comments = $this->get_comments($page);
 856
 857         $html = '';
 858         if ($nonjs) {
 859             $html .= html_writer::tag('h3', get_string('comments'));
 860             $html .= html_writer::start_tag('ul', array('id' => 'comment-list-'.$this->cid, 'class' => 'comment-list'));
 861         }
 862         // Reverse the comments array to display them in the correct direction
 863         foreach (array_reverse($comments) as $cmt) {
 864             $html .= html_writer::tag('li', $this->print_comment($cmt, $nonjs), array('id' => 'comment-'.$cmt->id.'-'.$this->cid));
 865         }
 866         if ($nonjs) {
 867             $html .= html_writer::end_tag('ul');
 868             $html .= $this->get_pagination($page);
 869         }
 870         if ($nonjs && $this->can_post()) {
 871             // Form to add comments
 872             $html .= html_writer::start_tag('form', array('method' => 'post', 'action' => new moodle_url('/comment/comment_post.php')));
 873             // Comment parameters
 874             $html .= html_writer::empty_tag('input', array('type' => 'hidden', 'name' => 'contextid', 'value' => $this->contextid));
 875             $html .= html_writer::empty_tag('input', array('type' => 'hidden', 'name' => 'action',    'value' => 'add'));
 876             $html .= html_writer::empty_tag('input', array('type' => 'hidden', 'name' => 'area',      'value' => $this->commentarea));
 877             $html .= html_writer::empty_tag('input', array('type' => 'hidden', 'name' => 'component', 'value' => $this->component));
 878             $html .= html_writer::empty_tag('input', array('type' => 'hidden', 'name' => 'itemid',    'value' => $this->itemid));
 879             $html .= html_writer::empty_tag('input', array('type' => 'hidden', 'name' => 'courseid',  'value' => $this->courseid));
 880             $html .= html_writer::empty_tag('input', array('type' => 'hidden', 'name' => 'sesskey',   'value' => sesskey()));
 881             $html .= html_writer::empty_tag('input', array('type' => 'hidden', 'name' => 'returnurl', 'value' => $PAGE->url));
 882             // Textarea for the actual comment
 883             $html .= html_writer::tag('textarea', '', array('name' => 'content', 'rows' => 2));
 884             // Submit button to add the comment
 885             $html .= html_writer::empty_tag('input', array('type' => 'submit', 'value' => get_string('submit')));
 886             $html .= html_writer::end_tag('form');
 887         }
 888         if ($return) {
 889             return $html;
 890         } else {
 891             echo $html;
 892         }
 893     }
 894
 895     /**
 896      * Returns an array containing comments in HTML format.
 897      *
 898      * @global core_renderer $OUTPUT
 899      * @param stdClass $cmt {
 900      *          id => int comment id
 901      *          content => string comment content
 902      *          format  => int comment text format
 903      *          timecreated => int comment's timecreated
 904      *          profileurl  => string link to user profile
 905      *          fullname    => comment author's full name
 906      *          avatar      => string user's avatar
 907      *          delete      => boolean does user have permission to delete comment?
 908      * }
 909      * @param bool $nonjs
 910      * @return array
 911      */
 912     public function print_comment($cmt, $nonjs = true) {
 913         global $OUTPUT;
 914         $patterns = array();
 915         $replacements = array();
 916
 917         if (!empty($cmt->delete) && empty($nonjs)) {
 918             $strdelete = get_string('deletecommentbyon', 'moodle', (object)['user' => $cmt->fullname, 'time' => $cmt->time]);
 919             $deletelink  = html_writer::start_tag('div', array('class'=>'comment-delete'));
 920             $deletelink .= html_writer::start_tag('a', array('href' => '#', 'id' => 'comment-delete-'.$this->cid.'-'.$cmt->id,
 921                                                              'title' => $strdelete));
 922
 923             $deletelink .= $OUTPUT->pix_icon('t/delete', get_string('delete'));
 924             $deletelink .= html_writer::end_tag('a');
 925             $deletelink .= html_writer::end_tag('div');
 926             $cmt->content = $deletelink . $cmt->content;
 927         }
 928         $patterns[] = '___picture___';
 929         $patterns[] = '___name___';
 930         $patterns[] = '___content___';
 931         $patterns[] = '___time___';
 932         $replacements[] = $cmt->avatar;
 933         $replacements[] = html_writer::link($cmt->profileurl, $cmt->fullname);
 934         $replacements[] = $cmt->content;
 935         $replacements[] = $cmt->time;
 936
 937         // use html template to format a single comment.
 938         return str_replace($patterns, $replacements, $this->template);
 939     }
 940
 941     /**
 942      * Revoke validate callbacks
 943      *
 944      * @param stdClass $params addtionall parameters need to add to callbacks
 945      */
 946     protected function validate($params=array()) {
 947         foreach ($params as $key=>$value) {
 948             $this->comment_param->$key = $value;
 949         }
 950         $validation = plugin_callback($this->plugintype, $this->pluginname, 'comment', 'validate', array($this->comment_param), false);
 951         if (!$validation) {
 952             throw new comment_exception('invalidcommentparam');
 953         }
 954     }
 955
 956     /**
 957      * Returns true if the user is able to view comments
 958      * @return bool
 959      */
 960     public function can_view() {
 961         $this->validate();
 962         return !empty($this->viewcap);
 963     }
 964
 965     /**
 966      * Returns true if the user can add comments against this comment description
 967      * @return bool
 968      */
 969     public function can_post() {
 970         $this->validate();
 971         return isloggedin() && !empty($this->postcap);
 972     }
 973
 974     /**
 975      * Returns true if the user can delete this comment
 976      * @param int $commentid
 977      * @return bool
 978      */
 979     public function can_delete($commentid) {
 980         $this->validate(array('commentid'=>$commentid));
 981         return has_capability('moodle/comment:delete', $this->context);
 982     }
 983
 984     /**
 985      * Returns the component associated with the comment.
 986      *
 987      * @return string
 988      */
 989     public function get_component() {
 990         return $this->component;
 991     }
 992
 993     /**
 994      * Do not call! I am a deprecated method because of the typo in my name.
 995      * @deprecated since 2.9
 996      * @see comment::get_component()
 997      * @return string
 998      */
 999     public function get_compontent() {
1000         return $this->get_component();
1001     }
1002
1003     /**
1004      * Returns the context associated with the comment
1005      * @return stdClass
1006      */
1007     public function get_context() {
1008         return $this->context;
1009     }
1010
1011     /**
1012      * Returns the course id associated with the comment
1013      * @return int
1014      */
1015     public function get_courseid() {
1016         return $this->courseid;
1017     }
1018
1019     /**
1020      * Returns the course module associated with the comment
1021      *
1022      * @return stdClass
1023      */
1024     public function get_cm() {
1025         return $this->cm;
1026     }
1027
1028     /**
1029      * Returns the item id associated with the comment
1030      *
1031      * @return int
1032      */
1033     public function get_itemid() {
1034         return $this->itemid;
1035     }
1036
1037     /**
1038      * Returns the comment area associated with the commentarea
1039      *
1040      * @return stdClass
1041      */
1042     public function get_commentarea() {
1043         return $this->commentarea;
1044     }
1045
1046     /**
1047      * Make the comments textarea fullwidth.
1048      *
1049      * @since 2.8.1 + 2.7.4
1050      * @param bool $fullwidth
1051      */
1052     public function set_fullwidth($fullwidth = true) {
1053         $this->fullwidth = (bool)$fullwidth;
1054     }
1055
1056     /**
1057      * Return the template.
1058      *
1059      * @since 3.1
1060      * @return string
1061      */
1062     public function get_template() {
1063         return $this->template;
1064     }
1065
1066     /**
1067      * Return the cid.
1068      *
1069      * @since 3.1
1070      * @return string
1071      */
1072     public function get_cid() {
1073         return $this->cid;
1074     }
1075
1076     /**
1077      * Return the link text.
1078      *
1079      * @since 3.1
1080      * @return string
1081      */
1082     public function get_linktext() {
1083         return $this->linktext;
1084     }
1085
1086     /**
1087      * Return no toggle.
1088      *
1089      * @since 3.1
1090      * @return bool
1091      */
1092     public function get_notoggle() {
1093         return $this->notoggle;
1094     }
1095
1096     /**
1097      * Return display total count.
1098      *
1099      * @since 3.1
1100      * @return bool
1101      */
1102     public function get_displaytotalcount() {
1103         return $this->displaytotalcount;
1104     }
1105
1106     /**
1107      * Return display cancel.
1108      *
1109      * @since 3.1
1110      * @return bool
1111      */
1112     public function get_displaycancel() {
1113         return $this->displaycancel;
1114     }
1115
1116     /**
1117      * Return fullwidth.
1118      *
1119      * @since 3.1
1120      * @return bool
1121      */
1122     public function get_fullwidth() {
1123         return $this->fullwidth;
1124     }
1125
1126     /**
1127      * Return autostart.
1128      *
1129      * @since 3.1
1130      * @return bool
1131      */
1132     public function get_autostart() {
1133         return $this->autostart;
1134     }
1135
1136 }
1137
1138 /**
1139  * Comment exception class
1140  *
1141  * @package   core
1142  * @copyright 2010 Dongsheng Cai {@link http://dongsheng.org}
1143  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
1144  */
1145 class comment_exception extends moodle_exception {
1146 }