blocks/moodleblock.class.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  * This file contains the parent class for moodle blocks, block_base.
  19  *
  20  * @package    core_block
  21  * @license    http://www.gnu.org/copyleft/gpl.html GNU Public License
  22  */
  23
  24 /// Constants
  25
  26 /**
  27  * Block type of list. Contents of block should be set as an associative array in the content object as items ($this->content->items). Optionally include footer text in $this->content->footer.
  28  */
  29 define('BLOCK_TYPE_LIST',    1);
  30
  31 /**
  32  * Block type of text. Contents of block should be set to standard html text in the content object as items ($this->content->text). Optionally include footer text in $this->content->footer.
  33  */
  34 define('BLOCK_TYPE_TEXT',    2);
  35 /**
  36  * Block type of tree. $this->content->items is a list of tree_item objects and $this->content->footer is a string.
  37  */
  38 define('BLOCK_TYPE_TREE',    3);
  39
  40 /**
  41  * Class for describing a moodle block, all Moodle blocks derive from this class
  42  *
  43  * @author Jon Papaioannou
  44  * @package core_block
  45  */
  46 class block_base {
  47
  48     /**
  49      * Internal var for storing/caching translated strings
  50      * @var string $str
  51      */
  52     var $str;
  53
  54     /**
  55      * The title of the block to be displayed in the block title area.
  56      * @var string $title
  57      */
  58     var $title         = NULL;
  59
  60     /**
  61      * The name of the block to be displayed in the block title area if the title is empty.
  62      * @var string arialabel
  63      */
  64     var $arialabel         = NULL;
  65
  66     /**
  67      * The type of content that this block creates. Currently support options - BLOCK_TYPE_LIST, BLOCK_TYPE_TEXT
  68      * @var int $content_type
  69      */
  70     var $content_type  = BLOCK_TYPE_TEXT;
  71
  72     /**
  73      * An object to contain the information to be displayed in the block.
  74      * @var stdObject $content
  75      */
  76     var $content       = NULL;
  77
  78     /**
  79      * The initialized instance of this block object.
  80      * @var block $instance
  81      */
  82     var $instance      = NULL;
  83
  84     /**
  85      * The page that this block is appearing on.
  86      * @var moodle_page
  87      */
  88     public $page       = NULL;
  89
  90     /**
  91      * This blocks's context.
  92      * @var stdClass
  93      */
  94     public $context    = NULL;
  95
  96     /**
  97      * An object containing the instance configuration information for the current instance of this block.
  98      * @var stdObject $config
  99      */
 100     var $config        = NULL;
 101
 102     /**
 103      * How often the cronjob should run, 0 if not at all.
 104      * @var int $cron
 105      */
 106
 107     var $cron          = NULL;
 108
 109 /// Class Functions
 110
 111     /**
 112      * Fake constructor to keep PHP5 happy
 113      *
 114      */
 115     function __construct() {
 116         $this->init();
 117     }
 118
 119     /**
 120      * Function that can be overridden to do extra cleanup before
 121      * the database tables are deleted. (Called once per block, not per instance!)
 122      */
 123     function before_delete() {
 124     }
 125
 126     /**
 127      * Returns the block name, as present in the class name,
 128      * the database, the block directory, etc etc.
 129      *
 130      * @return string
 131      */
 132     function name() {
 133         // Returns the block name, as present in the class name,
 134         // the database, the block directory, etc etc.
 135         static $myname;
 136         if ($myname === NULL) {
 137             $myname = strtolower(get_class($this));
 138             $myname = substr($myname, strpos($myname, '_') + 1);
 139         }
 140         return $myname;
 141     }
 142
 143     /**
 144      * Parent class version of this function simply returns NULL
 145      * This should be implemented by the derived class to return
 146      * the content object.
 147      *
 148      * @return stdObject
 149      */
 150     function get_content() {
 151         // This should be implemented by the derived class.
 152         return NULL;
 153     }
 154
 155     /**
 156      * Returns the class $title var value.
 157      *
 158      * Intentionally doesn't check if a title is set.
 159      * This is already done in {@link _self_test()}
 160      *
 161      * @return string $this->title
 162      */
 163     function get_title() {
 164         // Intentionally doesn't check if a title is set. This is already done in _self_test()
 165         return $this->title;
 166     }
 167
 168     /**
 169      * Returns the class $content_type var value.
 170      *
 171      * Intentionally doesn't check if content_type is set.
 172      * This is already done in {@link _self_test()}
 173      *
 174      * @return string $this->content_type
 175      */
 176     function get_content_type() {
 177         // Intentionally doesn't check if a content_type is set. This is already done in _self_test()
 178         return $this->content_type;
 179     }
 180
 181     /**
 182      * Returns true or false, depending on whether this block has any content to display
 183      * and whether the user has permission to view the block
 184      *
 185      * @return boolean
 186      */
 187     function is_empty() {
 188         if ( !has_capability('moodle/block:view', $this->context) ) {
 189             return true;
 190         }
 191
 192         $this->get_content();
 193         return(empty($this->content->text) && empty($this->content->footer));
 194     }
 195
 196     /**
 197      * First sets the current value of $this->content to NULL
 198      * then calls the block's {@link get_content()} function
 199      * to set its value back.
 200      *
 201      * @return stdObject
 202      */
 203     function refresh_content() {
 204         // Nothing special here, depends on content()
 205         $this->content = NULL;
 206         return $this->get_content();
 207     }
 208
 209     /**
 210      * Return a block_contents object representing the full contents of this block.
 211      *
 212      * This internally calls ->get_content(), and then adds the editing controls etc.
 213      *
 214      * You probably should not override this method, but instead override
 215      * {@link html_attributes()}, {@link formatted_contents()} or {@link get_content()},
 216      * {@link hide_header()}, {@link (get_edit_controls)}, etc.
 217      *
 218      * @return block_contents a representation of the block, for rendering.
 219      * @since Moodle 2.0.
 220      */
 221     public function get_content_for_output($output) {
 222         global $CFG;
 223
 224         $bc = new block_contents($this->html_attributes());
 225         $bc->attributes['data-block'] = $this->name();
 226         $bc->blockinstanceid = $this->instance->id;
 227         $bc->blockpositionid = $this->instance->blockpositionid;
 228
 229         if ($this->instance->visible) {
 230             $bc->content = $this->formatted_contents($output);
 231             if (!empty($this->content->footer)) {
 232                 $bc->footer = $this->content->footer;
 233             }
 234         } else {
 235             $bc->add_class('invisible');
 236         }
 237
 238         if (!$this->hide_header()) {
 239             $bc->title = $this->title;
 240         }
 241
 242         if (empty($bc->title)) {
 243             $bc->arialabel = new lang_string('pluginname', get_class($this));
 244             $this->arialabel = $bc->arialabel;
 245         }
 246
 247         if ($this->page->user_is_editing()) {
 248             $bc->controls = $this->page->blocks->edit_controls($this);
 249         } else {
 250             // we must not use is_empty on hidden blocks
 251             if ($this->is_empty() && !$bc->controls) {
 252                 return null;
 253             }
 254         }
 255
 256         if (empty($CFG->allowuserblockhiding)
 257                 || (empty($bc->content) && empty($bc->footer))
 258                 || !$this->instance_can_be_collapsed()) {
 259             $bc->collapsible = block_contents::NOT_HIDEABLE;
 260         } else if (get_user_preferences('block' . $bc->blockinstanceid . 'hidden', false)) {
 261             $bc->collapsible = block_contents::HIDDEN;
 262         } else {
 263             $bc->collapsible = block_contents::VISIBLE;
 264         }
 265
 266         if ($this->instance_can_be_docked() && !$this->hide_header()) {
 267             $bc->dockable = true;
 268         }
 269
 270         $bc->annotation = ''; // TODO MDL-19398 need to work out what to say here.
 271
 272         return $bc;
 273     }
 274
 275     /**
 276      * Convert the contents of the block to HTML.
 277      *
 278      * This is used by block base classes like block_list to convert the structured
 279      * $this->content->list and $this->content->icons arrays to HTML. So, in most
 280      * blocks, you probaby want to override the {@link get_contents()} method,
 281      * which generates that structured representation of the contents.
 282      *
 283      * @param $output The core_renderer to use when generating the output.
 284      * @return string the HTML that should appearn in the body of the block.
 285      * @since Moodle 2.0.
 286      */
 287     protected function formatted_contents($output) {
 288         $this->get_content();
 289         $this->get_required_javascript();
 290         if (!empty($this->content->text)) {
 291             return $this->content->text;
 292         } else {
 293             return '';
 294         }
 295     }
 296
 297     /**
 298      * Tests if this block has been implemented correctly.
 299      * Also, $errors isn't used right now
 300      *
 301      * @return boolean
 302      */
 303
 304     function _self_test() {
 305         // Tests if this block has been implemented correctly.
 306         // Also, $errors isn't used right now
 307         $errors = array();
 308
 309         $correct = true;
 310         if ($this->get_title() === NULL) {
 311             $errors[] = 'title_not_set';
 312             $correct = false;
 313         }
 314         if (!in_array($this->get_content_type(), array(BLOCK_TYPE_LIST, BLOCK_TYPE_TEXT, BLOCK_TYPE_TREE))) {
 315             $errors[] = 'invalid_content_type';
 316             $correct = false;
 317         }
 318         //following selftest was not working when roles&capabilities were used from block
 319 /*        if ($this->get_content() === NULL) {
 320             $errors[] = 'content_not_set';
 321             $correct = false;
 322         }*/
 323         $formats = $this->applicable_formats();
 324         if (empty($formats) || array_sum($formats) === 0) {
 325             $errors[] = 'no_formats';
 326             $correct = false;
 327         }
 328
 329         return $correct;
 330     }
 331
 332     /**
 333      * Subclasses should override this and return true if the
 334      * subclass block has a settings.php file.
 335      *
 336      * @return boolean
 337      */
 338     function has_config() {
 339         return false;
 340     }
 341
 342     /**
 343      * Default behavior: save all variables as $CFG properties
 344      * You don't need to override this if you 're satisfied with the above
 345      *
 346      * @deprecated since Moodle 2.9 MDL-49385 - Please use Admin Settings functionality to save block configuration.
 347      */
 348     function config_save($data) {
 349         throw new coding_exception('config_save() can not be used any more, use Admin Settings functionality to save block configuration.');
 350     }
 351
 352     /**
 353      * Which page types this block may appear on.
 354      *
 355      * The information returned here is processed by the
 356      * {@link blocks_name_allowed_in_format()} function. Look there if you need
 357      * to know exactly how this works.
 358      *
 359      * Default case: everything except mod and tag.
 360      *
 361      * @return array page-type prefix => true/false.
 362      */
 363     function applicable_formats() {
 364         // Default case: the block can be used in courses and site index, but not in activities
 365         return array('all' => true, 'mod' => false, 'tag' => false);
 366     }
 367
 368
 369     /**
 370      * Default return is false - header will be shown
 371      * @return boolean
 372      */
 373     function hide_header() {
 374         return false;
 375     }
 376
 377     /**
 378      * Return any HTML attributes that you want added to the outer <div> that
 379      * of the block when it is output.
 380      *
 381      * Because of the way certain JS events are wired it is a good idea to ensure
 382      * that the default values here still get set.
 383      * I found the easiest way to do this and still set anything you want is to
 384      * override it within your block in the following way
 385      *
 386      * <code php>
 387      * function html_attributes() {
 388      *    $attributes = parent::html_attributes();
 389      *    $attributes['class'] .= ' mynewclass';
 390      *    return $attributes;
 391      * }
 392      * </code>
 393      *
 394      * @return array attribute name => value.
 395      */
 396     function html_attributes() {
 397         $attributes = array(
 398             'id' => 'inst' . $this->instance->id,
 399             'class' => 'block_' . $this->name(). '  block',
 400             'role' => $this->get_aria_role()
 401         );
 402         if ($this->hide_header()) {
 403             $attributes['class'] .= ' no-header';
 404         }
 405         if ($this->instance_can_be_docked() && get_user_preferences('docked_block_instance_'.$this->instance->id, 0)) {
 406             $attributes['class'] .= ' dock_on_load';
 407         }
 408         return $attributes;
 409     }
 410
 411     /**
 412      * Set up a particular instance of this class given data from the block_insances
 413      * table and the current page. (See {@link block_manager::load_blocks()}.)
 414      *
 415      * @param stdClass $instance data from block_insances, block_positions, etc.
 416      * @param moodle_page $the page this block is on.
 417      */
 418     function _load_instance($instance, $page) {
 419         if (!empty($instance->configdata)) {
 420             $this->config = unserialize(base64_decode($instance->configdata));
 421         }
 422         $this->instance = $instance;
 423         $this->context = context_block::instance($instance->id);
 424         $this->page = $page;
 425         $this->specialization();
 426     }
 427
 428     /**
 429      * Allows the block to load any JS it requires into the page.
 430      *
 431      * By default this function simply permits the user to dock the block if it is dockable.
 432      */
 433     function get_required_javascript() {
 434         if ($this->instance_can_be_docked() && !$this->hide_header()) {
 435             user_preference_allow_ajax_update('docked_block_instance_'.$this->instance->id, PARAM_INT);
 436         }
 437     }
 438
 439     /**
 440      * This function is called on your subclass right after an instance is loaded
 441      * Use this function to act on instance data just after it's loaded and before anything else is done
 442      * For instance: if your block will have different title's depending on location (site, course, blog, etc)
 443      */
 444     function specialization() {
 445         // Just to make sure that this method exists.
 446     }
 447
 448     /**
 449      * Is each block of this type going to have instance-specific configuration?
 450      * Normally, this setting is controlled by {@link instance_allow_multiple()}: if multiple
 451      * instances are allowed, then each will surely need its own configuration. However, in some
 452      * cases it may be necessary to provide instance configuration to blocks that do not want to
 453      * allow multiple instances. In that case, make this function return true.
 454      * I stress again that this makes a difference ONLY if {@link instance_allow_multiple()} returns false.
 455      * @return boolean
 456      */
 457     function instance_allow_config() {
 458         return false;
 459     }
 460
 461     /**
 462      * Are you going to allow multiple instances of each block?
 463      * If yes, then it is assumed that the block WILL USE per-instance configuration
 464      * @return boolean
 465      */
 466     function instance_allow_multiple() {
 467         // Are you going to allow multiple instances of each block?
 468         // If yes, then it is assumed that the block WILL USE per-instance configuration
 469         return false;
 470     }
 471
 472     /**
 473      * Serialize and store config data
 474      */
 475     function instance_config_save($data, $nolongerused = false) {
 476         global $DB;
 477         $DB->set_field('block_instances', 'configdata', base64_encode(serialize($data)),
 478                 array('id' => $this->instance->id));
 479     }
 480
 481     /**
 482      * Replace the instance's configuration data with those currently in $this->config;
 483      */
 484     function instance_config_commit($nolongerused = false) {
 485         global $DB;
 486         $this->instance_config_save($this->config);
 487     }
 488
 489     /**
 490      * Do any additional initialization you may need at the time a new block instance is created
 491      * @return boolean
 492      */
 493     function instance_create() {
 494         return true;
 495     }
 496
 497     /**
 498      * Copy any block-specific data when copying to a new block instance.
 499      * @param int $fromid the id number of the block instance to copy from
 500      * @return boolean
 501      */
 502     public function instance_copy($fromid) {
 503         return true;
 504     }
 505
 506     /**
 507      * Delete everything related to this instance if you have been using persistent storage other than the configdata field.
 508      * @return boolean
 509      */
 510     function instance_delete() {
 511         return true;
 512     }
 513
 514     /**
 515      * Allows the block class to have a say in the user's ability to edit (i.e., configure) blocks of this type.
 516      * The framework has first say in whether this will be allowed (e.g., no editing allowed unless in edit mode)
 517      * but if the framework does allow it, the block can still decide to refuse.
 518      * @return boolean
 519      */
 520     function user_can_edit() {
 521         global $USER;
 522
 523         if (has_capability('moodle/block:edit', $this->context)) {
 524             return true;
 525         }
 526
 527         // The blocks in My Moodle are a special case.  We want them to inherit from the user context.
 528         if (!empty($USER->id)
 529             && $this->instance->parentcontextid == $this->page->context->id   // Block belongs to this page
 530             && $this->page->context->contextlevel == CONTEXT_USER             // Page belongs to a user
 531             && $this->page->context->instanceid == $USER->id) {               // Page belongs to this user
 532             return has_capability('moodle/my:manageblocks', $this->page->context);
 533         }
 534
 535         return false;
 536     }
 537
 538     /**
 539      * Allows the block class to have a say in the user's ability to create new instances of this block.
 540      * The framework has first say in whether this will be allowed (e.g., no adding allowed unless in edit mode)
 541      * but if the framework does allow it, the block can still decide to refuse.
 542      * This function has access to the complete page object, the creation related to which is being determined.
 543      *
 544      * @param moodle_page $page
 545      * @return boolean
 546      */
 547     function user_can_addto($page) {
 548         global $USER;
 549
 550         // The blocks in My Moodle are a special case and use a different capability.
 551         if (!empty($USER->id)
 552             && $page->context->contextlevel == CONTEXT_USER // Page belongs to a user
 553             && $page->context->instanceid == $USER->id // Page belongs to this user
 554             && $page->pagetype == 'my-index') { // Ensure we are on the My Moodle page
 555
 556             // If the block cannot be displayed on /my it is ok if the myaddinstance capability is not defined.
 557             $formats = $this->applicable_formats();
 558             // Is 'my' explicitly forbidden?
 559             // If 'all' has not been allowed, has 'my' been explicitly allowed?
 560             if ((isset($formats['my']) && $formats['my'] == false)
 561                 || (empty($formats['all']) && empty($formats['my']))) {
 562
 563                 // Block cannot be added to /my regardless of capabilities.
 564                 return false;
 565             } else {
 566                 $capability = 'block/' . $this->name() . ':myaddinstance';
 567                 return $this->has_add_block_capability($page, $capability)
 568                        && has_capability('moodle/my:manageblocks', $page->context);
 569             }
 570         }
 571
 572         $capability = 'block/' . $this->name() . ':addinstance';
 573         if ($this->has_add_block_capability($page, $capability)
 574                 && has_capability('moodle/block:edit', $page->context)) {
 575             return true;
 576         }
 577
 578         return false;
 579     }
 580
 581     /**
 582      * Returns true if the user can add a block to a page.
 583      *
 584      * @param moodle_page $page
 585      * @param string $capability the capability to check
 586      * @return boolean true if user can add a block, false otherwise.
 587      */
 588     private function has_add_block_capability($page, $capability) {
 589         // Check if the capability exists.
 590         if (!get_capability_info($capability)) {
 591             // Debug warning that the capability does not exist, but no more than once per page.
 592             static $warned = array();
 593             if (!isset($warned[$this->name()])) {
 594                 debugging('The block ' .$this->name() . ' does not define the standard capability ' .
 595                         $capability , DEBUG_DEVELOPER);
 596                 $warned[$this->name()] = 1;
 597             }
 598             // If the capability does not exist, the block can always be added.
 599             return true;
 600         } else {
 601             return has_capability($capability, $page->context);
 602         }
 603     }
 604
 605     static function get_extra_capabilities() {
 606         return array('moodle/block:view', 'moodle/block:edit');
 607     }
 608
 609     /**
 610      * Can be overridden by the block to prevent the block from being dockable.
 611      *
 612      * @return bool
 613      */
 614     public function instance_can_be_docked() {
 615         global $CFG;
 616         return (!empty($CFG->allowblockstodock) && $this->page->theme->enable_dock);
 617     }
 618
 619     /**
 620      * If overridden and set to false by the block it will not be hidable when
 621      * editing is turned on.
 622      *
 623      * @return bool
 624      */
 625     public function instance_can_be_hidden() {
 626         return true;
 627     }
 628
 629     /**
 630      * If overridden and set to false by the block it will not be collapsible.
 631      *
 632      * @return bool
 633      */
 634     public function instance_can_be_collapsed() {
 635         return true;
 636     }
 637
 638     /** @callback callback functions for comments api */
 639     public static function comment_template($options) {
 640         $ret = <<<EOD
 641 <div class="comment-userpicture">___picture___</div>
 642 <div class="comment-content">
 643     ___name___ - <span>___time___</span>
 644     <div>___content___</div>
 645 </div>
 646 EOD;
 647         return $ret;
 648     }
 649     public static function comment_permissions($options) {
 650         return array('view'=>true, 'post'=>true);
 651     }
 652     public static function comment_url($options) {
 653         return null;
 654     }
 655     public static function comment_display($comments, $options) {
 656         return $comments;
 657     }
 658     public static function comment_add(&$comments, $options) {
 659         return true;
 660     }
 661
 662     /**
 663      * Returns the aria role attribute that best describes this block.
 664      *
 665      * Region is the default, but this should be overridden by a block is there is a region child, or even better
 666      * a landmark child.
 667      *
 668      * Options are as follows:
 669      *    - landmark
 670      *      - application
 671      *      - banner
 672      *      - complementary
 673      *      - contentinfo
 674      *      - form
 675      *      - main
 676      *      - navigation
 677      *      - search
 678      *
 679      * @return string
 680      */
 681     public function get_aria_role() {
 682         return 'complementary';
 683     }
 684 }
 685
 686 /**
 687  * Specialized class for displaying a block with a list of icons/text labels
 688  *
 689  * The get_content method should set $this->content->items and (optionally)
 690  * $this->content->icons, instead of $this->content->text.
 691  *
 692  * @author Jon Papaioannou
 693  * @package core_block
 694  */
 695
 696 class block_list extends block_base {
 697     var $content_type  = BLOCK_TYPE_LIST;
 698
 699     function is_empty() {
 700         if ( !has_capability('moodle/block:view', $this->context) ) {
 701             return true;
 702         }
 703
 704         $this->get_content();
 705         return (empty($this->content->items) && empty($this->content->footer));
 706     }
 707
 708     protected function formatted_contents($output) {
 709         $this->get_content();
 710         $this->get_required_javascript();
 711         if (!empty($this->content->items)) {
 712             return $output->list_block_contents($this->content->icons, $this->content->items);
 713         } else {
 714             return '';
 715         }
 716     }
 717
 718     function html_attributes() {
 719         $attributes = parent::html_attributes();
 720         $attributes['class'] .= ' list_block';
 721         return $attributes;
 722     }
 723
 724 }
 725
 726 /**
 727  * Specialized class for displaying a tree menu.
 728  *
 729  * The {@link get_content()} method involves setting the content of
 730  * <code>$this->content->items</code> with an array of {@link tree_item}
 731  * objects (these are the top-level nodes). The {@link tree_item::children}
 732  * property may contain more tree_item objects, and so on. The tree_item class
 733  * itself is abstract and not intended for use, use one of it's subclasses.
 734  *
 735  * Unlike {@link block_list}, the icons are specified as part of the items,
 736  * not in a separate array.
 737  *
 738  * @author Alan Trick
 739  * @package core_block
 740  * @internal this extends block_list so we get is_empty() for free
 741  */
 742 class block_tree extends block_list {
 743
 744     /**
 745      * @var int specifies the manner in which contents should be added to this
 746      * block type. In this case <code>$this->content->items</code> is used with
 747      * {@link tree_item}s.
 748      */
 749     public $content_type = BLOCK_TYPE_TREE;
 750
 751     /**
 752      * Make the formatted HTML ouput.
 753      *
 754      * Also adds the required javascript call to the page output.
 755      *
 756      * @param core_renderer $output
 757      * @return string HTML
 758      */
 759     protected function formatted_contents($output) {
 760         // based of code in admin_tree
 761         global $PAGE; // TODO change this when there is a proper way for blocks to get stuff into head.
 762         static $eventattached;
 763         if ($eventattached===null) {
 764             $eventattached = true;
 765         }
 766         if (!$this->content) {
 767             $this->content = new stdClass;
 768             $this->content->items = array();
 769         }
 770         $this->get_required_javascript();
 771         $this->get_content();
 772         $content = $output->tree_block_contents($this->content->items,array('class'=>'block_tree list'));
 773         if (isset($this->id) && !is_numeric($this->id)) {
 774             $content = $output->box($content, 'block_tree_box', $this->id);
 775         }
 776         return $content;
 777     }
 778 }