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     /** @var stdClass comment paramaters for callback. */
 100     protected $comment_param;
 101
 102     /**
 103      * Construct function of comment class, initialise
 104      * class members
 105      *
 106      * @param stdClass $options {
 107      *            context => context context to use for the comment [required]
 108      *            component => string which plugin will comment being added to [required]
 109      *            itemid  => int the id of the associated item (forum post, glossary item etc) [required]
 110      *            area    => string comment area
 111      *            cm      => stdClass course module
 112      *            course  => course course object
 113      *            client_id => string an unique id to identify comment area
 114      *            autostart => boolean automatically expend comments
 115      *            showcount => boolean display the number of comments
 116      *            displaycancel => boolean display cancel button
 117      *            notoggle => boolean don't show/hide button
 118      *            linktext => string title of show/hide button
 119      * }
 120      */
 121     public function __construct(stdClass $options) {
 122         $this->viewcap = false;
 123         $this->postcap = false;
 124
 125         // setup client_id
 126         if (!empty($options->client_id)) {
 127             $this->cid = $options->client_id;
 128         } else {
 129             $this->cid = uniqid();
 130         }
 131
 132         // setup context
 133         if (!empty($options->context)) {
 134             $this->context = $options->context;
 135             $this->contextid = $this->context->id;
 136         } else if(!empty($options->contextid)) {
 137             $this->contextid = $options->contextid;
 138             $this->context = context::instance_by_id($this->contextid);
 139         } else {
 140             throw new \moodle_exception('invalidcontext');
 141         }
 142
 143         if (!empty($options->component)) {
 144             // set and validate component
 145             $this->set_component($options->component);
 146         } else {
 147             // component cannot be empty
 148             throw new comment_exception('invalidcomponent');
 149         }
 150
 151         // setup course
 152         // course will be used to generate user profile link
 153         if (!empty($options->course)) {
 154             $this->courseid = $options->course->id;
 155         } else if (!empty($options->courseid)) {
 156             $this->courseid = $options->courseid;
 157         } else {
 158             if ($coursecontext = $this->context->get_course_context(false)) {
 159                 $this->courseid = $coursecontext->instanceid;
 160             } else {
 161                 $this->courseid = SITEID;
 162             }
 163         }
 164
 165         // setup coursemodule
 166         if (!empty($options->cm)) {
 167             $this->cm = $options->cm;
 168         } else {
 169             $this->cm = null;
 170         }
 171
 172         // setup commentarea
 173         if (!empty($options->area)) {
 174             $this->commentarea = $options->area;
 175         }
 176
 177         // setup itemid
 178         if (!empty($options->itemid)) {
 179             $this->itemid = $options->itemid;
 180         } else {
 181             $this->itemid = 0;
 182         }
 183
 184         // setup customized linktext
 185         if (!empty($options->linktext)) {
 186             $this->linktext = $options->linktext;
 187         } else {
 188             $this->linktext = get_string('comments');
 189         }
 190
 191         // setup options for callback functions
 192         $this->comment_param = new stdClass();
 193         $this->comment_param->context     = $this->context;
 194         $this->comment_param->courseid    = $this->courseid;
 195         $this->comment_param->cm          = $this->cm;
 196         $this->comment_param->commentarea = $this->commentarea;
 197         $this->comment_param->itemid      = $this->itemid;
 198
 199         // setup notoggle
 200         if (!empty($options->notoggle)) {
 201             $this->set_notoggle($options->notoggle);
 202         }
 203
 204         // setup notoggle
 205         if (!empty($options->autostart)) {
 206             $this->set_autostart($options->autostart);
 207         }
 208
 209         // setup displaycancel
 210         if (!empty($options->displaycancel)) {
 211             $this->set_displaycancel($options->displaycancel);
 212         }
 213
 214         // setup displaytotalcount
 215         if (!empty($options->showcount)) {
 216             $this->set_displaytotalcount($options->showcount);
 217         }
 218
 219         // setting post and view permissions
 220         $this->check_permissions();
 221
 222         // load template
 223         $this->template = html_writer::start_tag('div', array('class' => 'comment-message'));
 224
 225         $this->template .= html_writer::start_tag('div', array('class' => 'comment-message-meta mr-3'));
 226
 227         $this->template .= html_writer::tag('span', '___picture___', array('class' => 'picture'));
 228         $this->template .= html_writer::tag('span', '___name___', array('class' => 'user')) . ' - ';
 229         $this->template .= html_writer::tag('span', '___time___', array('class' => 'time'));
 230
 231         $this->template .= html_writer::end_tag('div'); // .comment-message-meta
 232         $this->template .= html_writer::tag('div', '___content___', array('class' => 'text'));
 233
 234         $this->template .= html_writer::end_tag('div'); // .comment-message
 235
 236         if (!empty($this->plugintype)) {
 237             $this->template = plugin_callback($this->plugintype, $this->pluginname, 'comment', 'template', array($this->comment_param), $this->template);
 238         }
 239
 240         unset($options);
 241     }
 242
 243     /**
 244      * Receive nonjs comment parameters
 245      *
 246      * @param moodle_page $page The page object to initialise comments within
 247      *                          If not provided the global $PAGE is used
 248      */
 249     public static function init(moodle_page $page = null) {
 250         global $PAGE;
 251
 252         if (empty($page)) {
 253             $page = $PAGE;
 254         }
 255         // setup variables for non-js interface
 256         self::$nonjs = optional_param('nonjscomment', '', PARAM_ALPHANUM);
 257         self::$comment_itemid = optional_param('comment_itemid',  '', PARAM_INT);
 258         self::$comment_component = optional_param('comment_component', '', PARAM_COMPONENT);
 259         self::$comment_context = optional_param('comment_context', '', PARAM_INT);
 260         self::$comment_page = optional_param('comment_page',    '', PARAM_INT);
 261         self::$comment_area = optional_param('comment_area',    '', PARAM_AREA);
 262
 263         $page->requires->strings_for_js(array(
 264                 'addcomment',
 265                 'comments',
 266                 'commentscount',
 267                 'commentsrequirelogin',
 268                 'deletecommentbyon'
 269             ),
 270             'moodle'
 271         );
 272     }
 273
 274     /**
 275      * Sets the component.
 276      *
 277      * This method shouldn't be public, changing the component once it has been set potentially
 278      * invalidates permission checks.
 279      * A coding_error is now thrown if code attempts to change the component.
 280      *
 281      * @throws coding_exception if you try to change the component after it has been set.
 282      * @param string $component
 283      */
 284     public function set_component($component) {
 285         if (!empty($this->component) && $this->component !== $component) {
 286             throw new coding_exception('You cannot change the component of a comment once it has been set');
 287         }
 288         $this->component = $component;
 289         list($this->plugintype, $this->pluginname) = core_component::normalize_component($component);
 290     }
 291
 292     /**
 293      * Determines if the user can view the comment.
 294      *
 295      * @param bool $value
 296      */
 297     public function set_view_permission($value) {
 298         $this->viewcap = (bool)$value;
 299     }
 300
 301     /**
 302      * Determines if the user can post a comment
 303      *
 304      * @param bool $value
 305      */
 306     public function set_post_permission($value) {
 307         $this->postcap = (bool)$value;
 308     }
 309
 310     /**
 311      * check posting comments permission
 312      * It will check based on user roles and ask modules
 313      * If you need to check permission by modules, a
 314      * function named $pluginname_check_comment_post must be implemented
 315      */
 316     private function check_permissions() {
 317         $this->postcap = has_capability('moodle/comment:post', $this->context);
 318         $this->viewcap = has_capability('moodle/comment:view', $this->context);
 319         if (!empty($this->plugintype)) {
 320             $permissions = plugin_callback($this->plugintype, $this->pluginname, 'comment', 'permissions', array($this->comment_param), array('post'=>false, 'view'=>false));
 321             $this->postcap = $this->postcap && $permissions['post'];
 322             $this->viewcap = $this->viewcap && $permissions['view'];
 323         }
 324     }
 325
 326     /**
 327      * Gets a link for this page that will work with JS disabled.
 328      *
 329      * @global moodle_page $PAGE
 330      * @param moodle_page $page
 331      * @return moodle_url
 332      */
 333     public function get_nojslink(moodle_page $page = null) {
 334         if ($page === null) {
 335             global $PAGE;
 336             $page = $PAGE;
 337         }
 338
 339         $link = new moodle_url($page->url, array(
 340             'nonjscomment'    => true,
 341             'comment_itemid'  => $this->itemid,
 342             'comment_context' => $this->context->id,
 343             'comment_component' => $this->get_component(),
 344             'comment_area'    => $this->commentarea,
 345         ));
 346         $link->remove_params(array('comment_page'));
 347         return $link;
 348     }
 349
 350     /**
 351      * Sets the value of the notoggle option.
 352      *
 353      * If set to true then the user will not be able to expand and collase
 354      * the comment section.
 355      *
 356      * @param bool $newvalue
 357      */
 358     public function set_notoggle($newvalue = true) {
 359         $this->notoggle = (bool)$newvalue;
 360     }
 361
 362     /**
 363      * Sets the value of the autostart option.
 364      *
 365      * If set to true then the comments will be loaded during page load.
 366      * Normally this happens only once the user expands the comment section.
 367      *
 368      * @param bool $newvalue
 369      */
 370     public function set_autostart($newvalue = true) {
 371         $this->autostart = (bool)$newvalue;
 372     }
 373
 374     /**
 375      * Sets the displaycancel option
 376      *
 377      * If set to true then a cancel button will be shown when using the form
 378      * to post comments.
 379      *
 380      * @param bool $newvalue
 381      */
 382     public function set_displaycancel($newvalue = true) {
 383         $this->displaycancel = (bool)$newvalue;
 384     }
 385
 386     /**
 387      * Sets the displaytotalcount option
 388      *
 389      * If set to true then the total number of comments will be displayed
 390      * when printing comments.
 391      *
 392      * @param bool $newvalue
 393      */
 394     public function set_displaytotalcount($newvalue = true) {
 395         $this->displaytotalcount = (bool)$newvalue;
 396     }
 397
 398     /**
 399      * Initialises the JavaScript that enchances the comment API.
 400      *
 401      * @param moodle_page $page The moodle page object that the JavaScript should be
 402      *                          initialised for.
 403      */
 404     public function initialise_javascript(moodle_page $page) {
 405
 406         $options = new stdClass;
 407         $options->client_id   = $this->cid;
 408         $options->commentarea = $this->commentarea;
 409         $options->itemid      = $this->itemid;
 410         $options->page        = 0;
 411         $options->courseid    = $this->courseid;
 412         $options->contextid   = $this->contextid;
 413         $options->component   = $this->component;
 414         $options->notoggle    = $this->notoggle;
 415         $options->autostart   = $this->autostart;
 416
 417         $page->requires->js_init_call('M.core_comment.init', array($options), true);
 418
 419         return true;
 420     }
 421
 422     /**
 423      * Prepare comment code in html
 424      * @param  boolean $return
 425      * @return string|void
 426      */
 427     public function output($return = true) {
 428         global $PAGE, $OUTPUT;
 429         static $template_printed;
 430
 431         $this->initialise_javascript($PAGE);
 432
 433         if (!empty(self::$nonjs)) {
 434             // return non js comments interface
 435             return $this->print_comments(self::$comment_page, $return, true);
 436         }
 437
 438         $html = '';
 439
 440         // print html template
 441         // Javascript will use the template to render new comments
 442         if (empty($template_printed) && $this->can_view()) {
 443             $html .= html_writer::tag('div', $this->template, array('style' => 'display:none', 'id' => 'cmt-tmpl'));
 444             $template_printed = true;
 445         }
 446
 447         if ($this->can_view()) {
 448             // print commenting icon and tooltip
 449             $html .= html_writer::start_tag('div', array('class' => 'mdl-left'));
 450             $html .= html_writer::link($this->get_nojslink($PAGE), get_string('showcommentsnonjs'), array('class' => 'showcommentsnonjs'));
 451
 452             if (!$this->notoggle) {
 453                 // If toggling is enabled (notoggle=false) then print the controls to toggle
 454                 // comments open and closed
 455                 $countstring = '';
 456                 if ($this->displaytotalcount) {
 457                     $countstring = '('.$this->count().')';
 458                 }
 459                 $collapsedimage= 't/collapsed';
 460                 if (right_to_left()) {
 461                     $collapsedimage= 't/collapsed_rtl';
 462                 } else {
 463                     $collapsedimage= 't/collapsed';
 464                 }
 465                 $html .= html_writer::start_tag('a', array(
 466                     'class' => 'comment-link',
 467                     'id' => 'comment-link-'.$this->cid,
 468                     'href' => '#',
 469                     'role' => 'button',
 470                     'aria-expanded' => 'false')
 471                 );
 472                 $html .= $OUTPUT->pix_icon($collapsedimage, $this->linktext);
 473                 $html .= html_writer::tag('span', $this->linktext.' '.$countstring, array('id' => 'comment-link-text-'.$this->cid));
 474                 $html .= html_writer::end_tag('a');
 475             }
 476
 477             $html .= html_writer::start_tag('div', array('id' => 'comment-ctrl-'.$this->cid, 'class' => 'comment-ctrl'));
 478
 479             if ($this->autostart) {
 480                 // If autostart has been enabled print the comments list immediatly
 481                 $html .= html_writer::start_tag('ul', array('id' => 'comment-list-'.$this->cid, 'class' => 'comment-list comments-loaded'));
 482                 $html .= html_writer::tag('li', '', array('class' => 'first'));
 483                 $html .= $this->print_comments(0, true, false);
 484                 $html .= html_writer::end_tag('ul'); // .comment-list
 485                 $html .= $this->get_pagination(0);
 486             } else {
 487                 $html .= html_writer::start_tag('ul', array('id' => 'comment-list-'.$this->cid, 'class' => 'comment-list'));
 488                 $html .= html_writer::tag('li', '', array('class' => 'first'));
 489                 $html .= html_writer::end_tag('ul'); // .comment-list
 490                 $html .= html_writer::tag('div', '', array('id' => 'comment-pagination-'.$this->cid, 'class' => 'comment-pagination'));
 491             }
 492
 493             if ($this->can_post()) {
 494                 // print posting textarea
 495                 $textareaattrs = array(
 496                     'name' => 'content',
 497                     'rows' => 2,
 498                     'id' => 'dlg-content-'.$this->cid,
 499                     'aria-label' => get_string('addcomment')
 500                 );
 501                 if (!$this->fullwidth) {
 502                     $textareaattrs['cols'] = '20';
 503                 } else {
 504                     $textareaattrs['class'] = 'fullwidth';
 505                 }
 506
 507                 $html .= html_writer::start_tag('div', array('class' => 'comment-area'));
 508                 $html .= html_writer::start_tag('div', array('class' => 'db'));
 509                 $html .= html_writer::tag('label',
 510                         get_string('comment', 'comment'),
 511                         ['for' => 'dlg-content-'.$this->cid, 'class' => 'sr-only']);
 512                 $html .= html_writer::tag('textarea', '', $textareaattrs);
 513                 $html .= html_writer::end_tag('div'); // .db
 514
 515                 $html .= html_writer::start_tag('div', array('class' => 'fd', 'id' => 'comment-action-'.$this->cid));
 516                 $html .= html_writer::link('#', get_string('savecomment'), array('id' => 'comment-action-post-'.$this->cid));
 517
 518                 if ($this->displaycancel) {
 519                     $html .= html_writer::tag('span', ' | ');
 520                     $html .= html_writer::link('#', get_string('cancel'), array('id' => 'comment-action-cancel-'.$this->cid));
 521                 }
 522
 523                 $html .= html_writer::end_tag('div'); // .fd
 524                 $html .= html_writer::end_tag('div'); // .comment-area
 525                 $html .= html_writer::tag('div', '', array('class' => 'clearer'));
 526             }
 527
 528             $html .= html_writer::end_tag('div'); // .comment-ctrl
 529             $html .= html_writer::end_tag('div'); // .mdl-left
 530         } else {
 531             $html = '';
 532         }
 533
 534         if ($return) {
 535             return $html;
 536         } else {
 537             echo $html;
 538         }
 539     }
 540
 541     /**
 542      * Return matched comments
 543      *
 544      * @param  int $page
 545      * @param  str $sortdirection sort direction, ASC or DESC
 546      * @return array
 547      */
 548     public function get_comments($page = '', $sortdirection = 'DESC') {
 549         global $DB, $CFG, $USER, $OUTPUT;
 550         if (!$this->can_view()) {
 551             return false;
 552         }
 553         if (!is_numeric($page)) {
 554             $page = 0;
 555         }
 556         $params = array();
 557         $perpage = (!empty($CFG->commentsperpage))?$CFG->commentsperpage:15;
 558         $start = $page * $perpage;
 559         $userfieldsapi = \core_user\fields::for_userpic();
 560         $ufields = $userfieldsapi->get_sql('u', false, '', '', false)->selects;
 561
 562         list($componentwhere, $component) = $this->get_component_select_sql('c');
 563         if ($component) {
 564             $params['component'] = $component;
 565         }
 566
 567         $sortdirection = ($sortdirection === 'ASC') ? 'ASC' : 'DESC';
 568         $sql = "SELECT $ufields, c.id AS cid, c.content AS ccontent, c.format AS cformat, c.timecreated AS ctimecreated
 569                   FROM {comments} c
 570                   JOIN {user} u ON u.id = c.userid
 571                  WHERE c.contextid = :contextid AND
 572                        c.commentarea = :commentarea AND
 573                        c.itemid = :itemid AND
 574                        $componentwhere
 575               ORDER BY c.timecreated $sortdirection, c.id $sortdirection";
 576         $params['contextid'] = $this->contextid;
 577         $params['commentarea'] = $this->commentarea;
 578         $params['itemid'] = $this->itemid;
 579
 580         $comments = array();
 581         $formatoptions = array('overflowdiv' => true, 'blanktarget' => true);
 582         $rs = $DB->get_recordset_sql($sql, $params, $start, $perpage);
 583         foreach ($rs as $u) {
 584             $c = new stdClass();
 585             $c->id          = $u->cid;
 586             $c->content     = $u->ccontent;
 587             $c->format      = $u->cformat;
 588             $c->timecreated = $u->ctimecreated;
 589             $c->strftimeformat = get_string('strftimerecentfull', 'langconfig');
 590             $url = new moodle_url('/user/view.php', array('id'=>$u->id, 'course'=>$this->courseid));
 591             $c->profileurl = $url->out(false); // URL should not be escaped just yet.
 592             $c->fullname = fullname($u);
 593             $c->time = userdate($c->timecreated, $c->strftimeformat);
 594             $c->content = format_text($c->content, $c->format, $formatoptions);
 595             $c->avatar = $OUTPUT->user_picture($u, array('size' => 16));
 596             $c->userid = $u->id;
 597
 598             if ($this->can_delete($c)) {
 599                 $c->delete = true;
 600             }
 601             $comments[] = $c;
 602         }
 603         $rs->close();
 604
 605         if (!empty($this->plugintype)) {
 606             // moodle module will filter comments
 607             $comments = plugin_callback($this->plugintype, $this->pluginname, 'comment', 'display', array($comments, $this->comment_param), $comments);
 608         }
 609
 610         return $comments;
 611     }
 612
 613     /**
 614      * Returns an SQL fragment and param for selecting on component.
 615      * @param string $alias
 616      * @return array
 617      */
 618     protected function get_component_select_sql($alias = '') {
 619         $component = $this->get_component();
 620         if ($alias) {
 621             $alias = $alias.'.';
 622         }
 623         if (empty($component)) {
 624             $componentwhere = "{$alias}component IS NULL";
 625             $component = null;
 626         } else {
 627             $componentwhere = "({$alias}component IS NULL OR {$alias}component = :component)";
 628         }
 629         return array($componentwhere, $component);
 630     }
 631
 632     /**
 633      * Returns the number of comments associated with the details of this object
 634      *
 635      * @global moodle_database $DB
 636      * @return int
 637      */
 638     public function count() {
 639         global $DB;
 640         if ($this->totalcommentcount === null) {
 641             list($where, $component) = $this->get_component_select_sql();
 642             $where .= ' AND itemid = :itemid AND commentarea = :commentarea AND contextid = :contextid';
 643             $params = array(
 644                 'itemid' => $this->itemid,
 645                 'commentarea' => $this->commentarea,
 646                 'contextid' => $this->context->id,
 647             );
 648             if ($component) {
 649                 $params['component'] = $component;
 650             }
 651
 652             $this->totalcommentcount = $DB->count_records_select('comments', $where, $params);
 653         }
 654         return $this->totalcommentcount;
 655     }
 656
 657     /**
 658      * Returns HTML to display a pagination bar
 659      *
 660      * @global stdClass $CFG
 661      * @global core_renderer $OUTPUT
 662      * @param int $page
 663      * @return string
 664      */
 665     public function get_pagination($page = 0) {
 666         global $CFG, $OUTPUT;
 667         $count = $this->count();
 668         $perpage = (!empty($CFG->commentsperpage))?$CFG->commentsperpage:15;
 669         $pages = (int)ceil($count/$perpage);
 670         if ($pages == 1 || $pages == 0) {
 671             return html_writer::tag('div', '', array('id' => 'comment-pagination-'.$this->cid, 'class' => 'comment-pagination'));
 672         }
 673         if (!empty(self::$nonjs)) {
 674             // used in non-js interface
 675             return $OUTPUT->paging_bar($count, $page, $perpage, $this->get_nojslink(), 'comment_page');
 676         } else {
 677             // return ajax paging bar
 678             $str = '';
 679             $str .= '<div class="comment-paging" id="comment-pagination-'.$this->cid.'">';
 680             for ($p=0; $p<$pages; $p++) {
 681                 if ($p == $page) {
 682                     $class = 'curpage';
 683                 } else {
 684                     $class = 'pageno';
 685                 }
 686                 $str .= '<a href="#" class="'.$class.'" id="comment-page-'.$this->cid.'-'.$p.'">'.($p+1).'</a> ';
 687             }
 688             $str .= '</div>';
 689         }
 690         return $str;
 691     }
 692
 693     /**
 694      * Add a new comment
 695      *
 696      * @global moodle_database $DB
 697      * @param string $content
 698      * @param int $format
 699      * @return stdClass
 700      */
 701     public function add($content, $format = FORMAT_MOODLE) {
 702         global $CFG, $DB, $USER, $OUTPUT;
 703         if (!$this->can_post()) {
 704             throw new comment_exception('nopermissiontocomment');
 705         }
 706         $now = time();
 707         $newcmt = new stdClass;
 708         $newcmt->contextid    = $this->contextid;
 709         $newcmt->commentarea  = $this->commentarea;
 710         $newcmt->itemid       = $this->itemid;
 711         $newcmt->component    = !empty($this->component) ? $this->component : null;
 712         $newcmt->content      = $content;
 713         $newcmt->format       = $format;
 714         $newcmt->userid       = $USER->id;
 715         $newcmt->timecreated  = $now;
 716
 717         // This callback allow module to modify the content of comment, such as filter or replacement
 718         plugin_callback($this->plugintype, $this->pluginname, 'comment', 'add', array(&$newcmt, $this->comment_param));
 719
 720         $cmt_id = $DB->insert_record('comments', $newcmt);
 721         if (!empty($cmt_id)) {
 722             $newcmt->id = $cmt_id;
 723             $newcmt->strftimeformat = get_string('strftimerecentfull', 'langconfig');
 724             $newcmt->fullname = fullname($USER);
 725             $url = new moodle_url('/user/view.php', array('id' => $USER->id, 'course' => $this->courseid));
 726             $newcmt->profileurl = $url->out();
 727             $formatoptions = array('overflowdiv' => true, 'blanktarget' => true);
 728             $newcmt->content = format_text($newcmt->content, $newcmt->format, $formatoptions);
 729             $newcmt->avatar = $OUTPUT->user_picture($USER, array('size'=>16));
 730
 731             $commentlist = array($newcmt);
 732
 733             if (!empty($this->plugintype)) {
 734                 // Call the display callback to allow the plugin to format the newly added comment.
 735                 $commentlist = plugin_callback($this->plugintype,
 736                                                $this->pluginname,
 737                                                'comment',
 738                                                'display',
 739                                                array($commentlist, $this->comment_param),
 740                                                $commentlist);
 741                 $newcmt = $commentlist[0];
 742             }
 743             $newcmt->time = userdate($newcmt->timecreated, $newcmt->strftimeformat);
 744
 745             // Trigger comment created event.
 746             if (core_component::is_core_subsystem($this->component)) {
 747                 $eventclassname = '\\core\\event\\' . $this->component . '_comment_created';
 748             } else {
 749                 $eventclassname = '\\' . $this->component . '\\event\comment_created';
 750             }
 751             if (class_exists($eventclassname)) {
 752                 $event = $eventclassname::create(
 753                         array(
 754                             'context' => $this->context,
 755                             'objectid' => $newcmt->id,
 756                             'other' => array(
 757                                 'itemid' => $this->itemid
 758                                 )
 759                             ));
 760                 $event->trigger();
 761             }
 762
 763             return $newcmt;
 764         } else {
 765             throw new comment_exception('dbupdatefailed');
 766         }
 767     }
 768
 769     /**
 770      * delete by context, commentarea and itemid
 771      * @param stdClass|array $param {
 772      *            contextid => int the context in which the comments exist [required]
 773      *            commentarea => string the comment area [optional]
 774      *            itemid => int comment itemid [optional]
 775      * }
 776      * @return boolean
 777      */
 778     public static function delete_comments($param) {
 779         global $DB;
 780         $param = (array)$param;
 781         if (empty($param['contextid'])) {
 782             return false;
 783         }
 784         $DB->delete_records('comments', $param);
 785         return true;
 786     }
 787
 788     /**
 789      * Delete page_comments in whole course, used by course reset
 790      *
 791      * @param stdClass $context course context
 792      */
 793     public static function reset_course_page_comments($context) {
 794         global $DB;
 795         $contexts = array();
 796         $contexts[] = $context->id;
 797         $children = $context->get_child_contexts();
 798         foreach ($children as $c) {
 799             $contexts[] = $c->id;
 800         }
 801         list($ids, $params) = $DB->get_in_or_equal($contexts);
 802         $DB->delete_records_select('comments', "commentarea='page_comments' AND contextid $ids", $params);
 803     }
 804
 805     /**
 806      * Delete a comment
 807      *
 808      * @param  int|stdClass $comment The id of a comment, or a comment record.
 809      * @return bool
 810      */
 811     public function delete($comment) {
 812         global $DB;
 813         if (is_object($comment)) {
 814             $commentid = $comment->id;
 815         } else {
 816             $commentid = $comment;
 817             $comment = $DB->get_record('comments', ['id' => $commentid]);
 818         }
 819
 820         if (!$comment) {
 821             throw new comment_exception('dbupdatefailed');
 822         }
 823         if (!$this->can_delete($comment)) {
 824             throw new comment_exception('nopermissiontocomment');
 825         }
 826         $DB->delete_records('comments', array('id'=>$commentid));
 827         // Trigger comment delete event.
 828         if (core_component::is_core_subsystem($this->component)) {
 829             $eventclassname = '\\core\\event\\' . $this->component . '_comment_deleted';
 830         } else {
 831             $eventclassname = '\\' . $this->component . '\\event\comment_deleted';
 832         }
 833         if (class_exists($eventclassname)) {
 834             $event = $eventclassname::create(
 835                     array(
 836                         'context' => $this->context,
 837                         'objectid' => $commentid,
 838                         'other' => array(
 839                             'itemid' => $this->itemid
 840                             )
 841                         ));
 842             $event->add_record_snapshot('comments', $comment);
 843             $event->trigger();
 844         }
 845         return true;
 846     }
 847
 848     /**
 849      * Print comments
 850      *
 851      * @param int $page
 852      * @param bool $return return comments list string or print it out
 853      * @param bool $nonjs print nonjs comments list or not?
 854      * @return string|void
 855      */
 856     public function print_comments($page = 0, $return = true, $nonjs = true) {
 857         global $DB, $CFG, $PAGE;
 858
 859         if (!$this->can_view()) {
 860             return '';
 861         }
 862
 863         if (!(self::$comment_itemid == $this->itemid &&
 864             self::$comment_context == $this->context->id &&
 865             self::$comment_area == $this->commentarea &&
 866             self::$comment_component == $this->component
 867         )) {
 868             $page = 0;
 869         }
 870         $comments = $this->get_comments($page);
 871
 872         $html = '';
 873         if ($nonjs) {
 874             $html .= html_writer::tag('h3', get_string('comments'));
 875             $html .= html_writer::start_tag('ul', array('id' => 'comment-list-'.$this->cid, 'class' => 'comment-list'));
 876         }
 877         // Reverse the comments array to display them in the correct direction
 878         foreach (array_reverse($comments) as $cmt) {
 879             $html .= html_writer::tag('li', $this->print_comment($cmt, $nonjs), array('id' => 'comment-'.$cmt->id.'-'.$this->cid));
 880         }
 881         if ($nonjs) {
 882             $html .= html_writer::end_tag('ul');
 883             $html .= $this->get_pagination($page);
 884         }
 885         if ($nonjs && $this->can_post()) {
 886             // Form to add comments
 887             $html .= html_writer::start_tag('form', array('method' => 'post', 'action' => new moodle_url('/comment/comment_post.php')));
 888             // Comment parameters
 889             $html .= html_writer::empty_tag('input', array('type' => 'hidden', 'name' => 'contextid', 'value' => $this->contextid));
 890             $html .= html_writer::empty_tag('input', array('type' => 'hidden', 'name' => 'action',    'value' => 'add'));
 891             $html .= html_writer::empty_tag('input', array('type' => 'hidden', 'name' => 'area',      'value' => $this->commentarea));
 892             $html .= html_writer::empty_tag('input', array('type' => 'hidden', 'name' => 'component', 'value' => $this->component));
 893             $html .= html_writer::empty_tag('input', array('type' => 'hidden', 'name' => 'itemid',    'value' => $this->itemid));
 894             $html .= html_writer::empty_tag('input', array('type' => 'hidden', 'name' => 'courseid',  'value' => $this->courseid));
 895             $html .= html_writer::empty_tag('input', array('type' => 'hidden', 'name' => 'sesskey',   'value' => sesskey()));
 896             $html .= html_writer::empty_tag('input', array('type' => 'hidden', 'name' => 'returnurl', 'value' => $PAGE->url));
 897             // Textarea for the actual comment
 898             $html .= html_writer::tag('textarea', '', array('name' => 'content', 'rows' => 2));
 899             // Submit button to add the comment
 900             $html .= html_writer::empty_tag('input', array('type' => 'submit', 'value' => get_string('submit')));
 901             $html .= html_writer::end_tag('form');
 902         }
 903         if ($return) {
 904             return $html;
 905         } else {
 906             echo $html;
 907         }
 908     }
 909
 910     /**
 911      * Returns an array containing comments in HTML format.
 912      *
 913      * @global core_renderer $OUTPUT
 914      * @param stdClass $cmt {
 915      *          id => int comment id
 916      *          content => string comment content
 917      *          format  => int comment text format
 918      *          timecreated => int comment's timecreated
 919      *          profileurl  => string link to user profile
 920      *          fullname    => comment author's full name
 921      *          avatar      => string user's avatar
 922      *          delete      => boolean does user have permission to delete comment?
 923      * }
 924      * @param bool $nonjs
 925      * @return array
 926      */
 927     public function print_comment($cmt, $nonjs = true) {
 928         global $OUTPUT;
 929         $patterns = array();
 930         $replacements = array();
 931
 932         if (!empty($cmt->delete) && empty($nonjs)) {
 933             $strdelete = get_string('deletecommentbyon', 'moodle', (object)['user' => $cmt->fullname, 'time' => $cmt->time]);
 934             $deletelink  = html_writer::start_tag('div', array('class'=>'comment-delete'));
 935             $deletelink .= html_writer::start_tag('a', array('href' => '#', 'id' => 'comment-delete-'.$this->cid.'-'.$cmt->id,
 936                 'class' => 'icon-no-margin', 'title' => $strdelete));
 937
 938             $deletelink .= $OUTPUT->pix_icon('t/delete', $strdelete);
 939             $deletelink .= html_writer::end_tag('a');
 940             $deletelink .= html_writer::end_tag('div');
 941             $cmt->content = $deletelink . $cmt->content;
 942         }
 943         $patterns[] = '___picture___';
 944         $patterns[] = '___name___';
 945         $patterns[] = '___content___';
 946         $patterns[] = '___time___';
 947         $replacements[] = $cmt->avatar;
 948         $replacements[] = html_writer::link($cmt->profileurl, $cmt->fullname);
 949         $replacements[] = $cmt->content;
 950         $replacements[] = $cmt->time;
 951
 952         // use html template to format a single comment.
 953         return str_replace($patterns, $replacements, $this->template);
 954     }
 955
 956     /**
 957      * Revoke validate callbacks
 958      *
 959      * @param stdClass $params addtionall parameters need to add to callbacks
 960      */
 961     protected function validate($params=array()) {
 962         foreach ($params as $key=>$value) {
 963             $this->comment_param->$key = $value;
 964         }
 965         $validation = plugin_callback($this->plugintype, $this->pluginname, 'comment', 'validate', array($this->comment_param), false);
 966         if (!$validation) {
 967             throw new comment_exception('invalidcommentparam');
 968         }
 969     }
 970
 971     /**
 972      * Returns true if the user is able to view comments
 973      * @return bool
 974      */
 975     public function can_view() {
 976         $this->validate();
 977         return !empty($this->viewcap);
 978     }
 979
 980     /**
 981      * Returns true if the user can add comments against this comment description
 982      * @return bool
 983      */
 984     public function can_post() {
 985         $this->validate();
 986         return isloggedin() && !empty($this->postcap);
 987     }
 988
 989     /**
 990      * Returns true if the user can delete this comment.
 991      *
 992      * The user can delete comments if it is one they posted and they can still make posts,
 993      * or they have the capability to delete comments.
 994      *
 995      * A database call is avoided if a comment record is passed.
 996      *
 997      * @param int|stdClass $comment The id of a comment, or a comment record.
 998      * @return bool
 999      */
1000     public function can_delete($comment) {
1001         global $USER, $DB;
1002         if (is_object($comment)) {
1003             $commentid = $comment->id;
1004         } else {
1005             $commentid = $comment;
1006         }
1007
1008         $this->validate(array('commentid'=>$commentid));
1009
1010         if (!is_object($comment)) {
1011             // Get the comment record from the database.
1012             $comment = $DB->get_record('comments', array('id' => $commentid), 'id, userid', MUST_EXIST);
1013         }
1014
1015         $hascapability = has_capability('moodle/comment:delete', $this->context);
1016         $owncomment = $USER->id == $comment->userid;
1017
1018         return ($hascapability || ($owncomment && $this->can_post()));
1019     }
1020
1021     /**
1022      * Returns the component associated with the comment.
1023      *
1024      * @return string
1025      */
1026     public function get_component() {
1027         return $this->component;
1028     }
1029
1030     /**
1031      * Do not call! I am a deprecated method because of the typo in my name.
1032      * @deprecated since 2.9
1033      * @see comment::get_component()
1034      * @return string
1035      */
1036     public function get_compontent() {
1037         return $this->get_component();
1038     }
1039
1040     /**
1041      * Returns the context associated with the comment
1042      * @return stdClass
1043      */
1044     public function get_context() {
1045         return $this->context;
1046     }
1047
1048     /**
1049      * Returns the course id associated with the comment
1050      * @return int
1051      */
1052     public function get_courseid() {
1053         return $this->courseid;
1054     }
1055
1056     /**
1057      * Returns the course module associated with the comment
1058      *
1059      * @return stdClass
1060      */
1061     public function get_cm() {
1062         return $this->cm;
1063     }
1064
1065     /**
1066      * Returns the item id associated with the comment
1067      *
1068      * @return int
1069      */
1070     public function get_itemid() {
1071         return $this->itemid;
1072     }
1073
1074     /**
1075      * Returns the comment area associated with the commentarea
1076      *
1077      * @return stdClass
1078      */
1079     public function get_commentarea() {
1080         return $this->commentarea;
1081     }
1082
1083     /**
1084      * Make the comments textarea fullwidth.
1085      *
1086      * @since 2.8.1 + 2.7.4
1087      * @param bool $fullwidth
1088      */
1089     public function set_fullwidth($fullwidth = true) {
1090         $this->fullwidth = (bool)$fullwidth;
1091     }
1092
1093     /**
1094      * Return the template.
1095      *
1096      * @since 3.1
1097      * @return string
1098      */
1099     public function get_template() {
1100         return $this->template;
1101     }
1102
1103     /**
1104      * Return the cid.
1105      *
1106      * @since 3.1
1107      * @return string
1108      */
1109     public function get_cid() {
1110         return $this->cid;
1111     }
1112
1113     /**
1114      * Return the link text.
1115      *
1116      * @since 3.1
1117      * @return string
1118      */
1119     public function get_linktext() {
1120         return $this->linktext;
1121     }
1122
1123     /**
1124      * Return no toggle.
1125      *
1126      * @since 3.1
1127      * @return bool
1128      */
1129     public function get_notoggle() {
1130         return $this->notoggle;
1131     }
1132
1133     /**
1134      * Return display total count.
1135      *
1136      * @since 3.1
1137      * @return bool
1138      */
1139     public function get_displaytotalcount() {
1140         return $this->displaytotalcount;
1141     }
1142
1143     /**
1144      * Return display cancel.
1145      *
1146      * @since 3.1
1147      * @return bool
1148      */
1149     public function get_displaycancel() {
1150         return $this->displaycancel;
1151     }
1152
1153     /**
1154      * Return fullwidth.
1155      *
1156      * @since 3.1
1157      * @return bool
1158      */
1159     public function get_fullwidth() {
1160         return $this->fullwidth;
1161     }
1162
1163     /**
1164      * Return autostart.
1165      *
1166      * @since 3.1
1167      * @return bool
1168      */
1169     public function get_autostart() {
1170         return $this->autostart;
1171     }
1172
1173 }
1174
1175 /**
1176  * Comment exception class
1177  *
1178  * @package   core
1179  * @copyright 2010 Dongsheng Cai {@link http://dongsheng.org}
1180  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
1181  */
1182 class comment_exception extends moodle_exception {
1183 }