lib/outputrequirementslib.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  * Library functions to facilitate the use of JavaScript in Moodle.
  19  *
  20  * Note: you can find history of this file in lib/ajax/ajaxlib.php
  21  *
  22  * @copyright 2009 Tim Hunt, 2010 Petr Skoda
  23  * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  24  * @package core
  25  * @category output
  26  */
  27
  28 defined('MOODLE_INTERNAL') || die();
  29
  30 /**
  31  * This class tracks all the things that are needed by the current page.
  32  *
  33  * Normally, the only instance of this  class you will need to work with is the
  34  * one accessible via $PAGE->requires.
  35  *
  36  * Typical usage would be
  37  * <pre>
  38  *     $PAGE->requires->js_call_amd('mod_forum/view', 'init');
  39  * </pre>
  40  *
  41  * It also supports obsoleted coding style with/without YUI3 modules.
  42  * <pre>
  43  *     $PAGE->requires->js_init_call('M.mod_forum.init_view');
  44  *     $PAGE->requires->css('/mod/mymod/userstyles.php?id='.$id); // not overridable via themes!
  45  *     $PAGE->requires->js('/mod/mymod/script.js');
  46  *     $PAGE->requires->js('/mod/mymod/small_but_urgent.js', true);
  47  *     $PAGE->requires->js_function_call('init_mymod', array($data), true);
  48  * </pre>
  49  *
  50  * There are some natural restrictions on some methods. For example, {@link css()}
  51  * can only be called before the <head> tag is output. See the comments on the
  52  * individual methods for details.
  53  *
  54  * @copyright 2009 Tim Hunt, 2010 Petr Skoda
  55  * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  56  * @since Moodle 2.0
  57  * @package core
  58  * @category output
  59  */
  60 class page_requirements_manager {
  61
  62     /**
  63      * @var array List of string available from JS
  64      */
  65     protected $stringsforjs = array();
  66
  67     /**
  68      * @var array List of get_string $a parameters - used for validation only.
  69      */
  70     protected $stringsforjs_as = array();
  71
  72     /**
  73      * @var array List of JS variables to be initialised
  74      */
  75     protected $jsinitvariables = array('head'=>array(), 'footer'=>array());
  76
  77     /**
  78      * @var array Included JS scripts
  79      */
  80     protected $jsincludes = array('head'=>array(), 'footer'=>array());
  81
  82     /**
  83      * @var array Inline scripts using RequireJS module loading.
  84      */
  85     protected $amdjscode = array('');
  86
  87     /**
  88      * @var array List of needed function calls
  89      */
  90     protected $jscalls = array('normal'=>array(), 'ondomready'=>array());
  91
  92     /**
  93      * @var array List of skip links, those are needed for accessibility reasons
  94      */
  95     protected $skiplinks = array();
  96
  97     /**
  98      * @var array Javascript code used for initialisation of page, it should
  99      * be relatively small
 100      */
 101     protected $jsinitcode = array();
 102
 103     /**
 104      * @var array of moodle_url Theme sheets, initialised only from core_renderer
 105      */
 106     protected $cssthemeurls = array();
 107
 108     /**
 109      * @var array of moodle_url List of custom theme sheets, these are strongly discouraged!
 110      * Useful mostly only for CSS submitted by teachers that is not part of the theme.
 111      */
 112     protected $cssurls = array();
 113
 114     /**
 115      * @var array List of requested event handlers
 116      */
 117     protected $eventhandlers = array();
 118
 119     /**
 120      * @var array Extra modules
 121      */
 122     protected $extramodules = array();
 123
 124     /**
 125      * @var array trackes the names of bits of HTML that are only required once
 126      * per page. See {@link has_one_time_item_been_created()},
 127      * {@link set_one_time_item_created()} and {@link should_create_one_time_item_now()}.
 128      */
 129     protected $onetimeitemsoutput = array();
 130
 131     /**
 132      * @var bool Flag indicated head stuff already printed
 133      */
 134     protected $headdone = false;
 135
 136     /**
 137      * @var bool Flag indicating top of body already printed
 138      */
 139     protected $topofbodydone = false;
 140
 141     /**
 142      * @var stdClass YUI PHPLoader instance responsible for YUI3 loading from PHP only
 143      */
 144     protected $yui3loader;
 145
 146     /**
 147      * @var YUI_config default YUI loader configuration
 148      */
 149     protected $YUI_config;
 150
 151     /**
 152      * @var array $yuicssmodules
 153      */
 154     protected $yuicssmodules = array();
 155
 156     /**
 157      * @var array Some config vars exposed in JS, please no secret stuff there
 158      */
 159     protected $M_cfg;
 160
 161     /**
 162      * @var array list of requested jQuery plugins
 163      */
 164     protected $jqueryplugins = array();
 165
 166     /**
 167      * @var array list of jQuery plugin overrides
 168      */
 169     protected $jquerypluginoverrides = array();
 170
 171     /**
 172      * Page requirements constructor.
 173      */
 174     public function __construct() {
 175         global $CFG;
 176
 177         // You may need to set up URL rewrite rule because oversized URLs might not be allowed by web server.
 178         $sep = empty($CFG->yuislasharguments) ? '?' : '/';
 179
 180         $this->yui3loader = new stdClass();
 181         $this->YUI_config = new YUI_config();
 182
 183         // Set up some loader options.
 184         $this->yui3loader->local_base = $CFG->wwwroot . '/lib/yuilib/'. $CFG->yui3version . '/';
 185         $this->yui3loader->local_comboBase = $CFG->wwwroot . '/theme/yui_combo.php'.$sep;
 186
 187         $this->yui3loader->base = $this->yui3loader->local_base;
 188         $this->yui3loader->comboBase = $this->yui3loader->local_comboBase;
 189
 190         // Enable combo loader? This significantly helps with caching and performance!
 191         $this->yui3loader->combine = !empty($CFG->yuicomboloading);
 192
 193         $jsrev = $this->get_jsrev();
 194
 195         // Set up JS YUI loader helper object.
 196         $this->YUI_config->base         = $this->yui3loader->base;
 197         $this->YUI_config->comboBase    = $this->yui3loader->comboBase;
 198         $this->YUI_config->combine      = $this->yui3loader->combine;
 199
 200         // If we've had to patch any YUI modules between releases, we must override the YUI configuration to include them.
 201         // For important information on patching YUI modules, please see http://docs.moodle.org/dev/YUI/Patching.
 202         if (!empty($CFG->yuipatchedmodules) && !empty($CFG->yuipatchlevel)) {
 203             $this->YUI_config->define_patched_core_modules($this->yui3loader->local_comboBase,
 204                     $CFG->yui3version,
 205                     $CFG->yuipatchlevel,
 206                     $CFG->yuipatchedmodules);
 207         }
 208
 209         $configname = $this->YUI_config->set_config_source('lib/yui/config/yui2.js');
 210         $this->YUI_config->add_group('yui2', array(
 211             // Loader configuration for our 2in3.
 212             'base' => $CFG->wwwroot . '/lib/yuilib/2in3/' . $CFG->yui2version . '/build/',
 213             'comboBase' => $CFG->wwwroot . '/theme/yui_combo.php'.$sep,
 214             'combine' => $this->yui3loader->combine,
 215             'ext' => false,
 216             'root' => '2in3/' . $CFG->yui2version .'/build/',
 217             'patterns' => array(
 218                 'yui2-' => array(
 219                     'group' => 'yui2',
 220                     'configFn' => $configname,
 221                 )
 222             )
 223         ));
 224         $configname = $this->YUI_config->set_config_source('lib/yui/config/moodle.js');
 225         $this->YUI_config->add_group('moodle', array(
 226             'name' => 'moodle',
 227             'base' => $CFG->wwwroot . '/theme/yui_combo.php' . $sep . 'm/' . $jsrev . '/',
 228             'combine' => $this->yui3loader->combine,
 229             'comboBase' => $CFG->wwwroot . '/theme/yui_combo.php'.$sep,
 230             'ext' => false,
 231             'root' => 'm/'.$jsrev.'/', // Add the rev to the root path so that we can control caching.
 232             'patterns' => array(
 233                 'moodle-' => array(
 234                     'group' => 'moodle',
 235                     'configFn' => $configname,
 236                 )
 237             )
 238         ));
 239
 240         $this->YUI_config->add_group('gallery', array(
 241             'name' => 'gallery',
 242             'base' => $CFG->wwwroot . '/lib/yuilib/gallery/',
 243             'combine' => $this->yui3loader->combine,
 244             'comboBase' => $CFG->wwwroot . '/theme/yui_combo.php' . $sep,
 245             'ext' => false,
 246             'root' => 'gallery/' . $jsrev . '/',
 247             'patterns' => array(
 248                 'gallery-' => array(
 249                     'group' => 'gallery',
 250                 )
 251             )
 252         ));
 253
 254         // Set some more loader options applying to groups too.
 255         if ($CFG->debugdeveloper) {
 256             // When debugging is enabled, we want to load the non-minified (RAW) versions of YUI library modules rather
 257             // than the DEBUG versions as these generally generate too much logging for our purposes.
 258             // However we do want the DEBUG versions of our Moodle-specific modules.
 259             // To debug a YUI-specific issue, change the yui3loader->filter value to DEBUG.
 260             $this->YUI_config->filter = 'RAW';
 261             $this->YUI_config->groups['moodle']['filter'] = 'DEBUG';
 262
 263             // We use the yui3loader->filter setting when writing the YUI3 seed scripts into the header.
 264             $this->yui3loader->filter = $this->YUI_config->filter;
 265             $this->YUI_config->debug = true;
 266         } else {
 267             $this->yui3loader->filter = null;
 268             $this->YUI_config->groups['moodle']['filter'] = null;
 269             $this->YUI_config->debug = false;
 270         }
 271
 272         // Include the YUI config log filters.
 273         if (!empty($CFG->yuilogexclude) && is_array($CFG->yuilogexclude)) {
 274             $this->YUI_config->logExclude = $CFG->yuilogexclude;
 275         }
 276         if (!empty($CFG->yuiloginclude) && is_array($CFG->yuiloginclude)) {
 277             $this->YUI_config->logInclude = $CFG->yuiloginclude;
 278         }
 279         if (!empty($CFG->yuiloglevel)) {
 280             $this->YUI_config->logLevel = $CFG->yuiloglevel;
 281         }
 282
 283         // Add the moodle group's module data.
 284         $this->YUI_config->add_moodle_metadata();
 285
 286         // Every page should include definition of following modules.
 287         $this->js_module($this->find_module('core_filepicker'));
 288         $this->js_module($this->find_module('core_comment'));
 289     }
 290
 291     /**
 292      * Return the safe config values that get set for javascript in "M.cfg".
 293      *
 294      * @since 2.9
 295      * @return array List of safe config values that are available to javascript.
 296      */
 297     public function get_config_for_javascript(moodle_page $page, renderer_base $renderer) {
 298         global $CFG;
 299
 300         if (empty($this->M_cfg)) {
 301
 302             $iconsystem = \core\output\icon_system::instance();
 303
 304             // It is possible that the $page->context is null, so we can't use $page->context->id.
 305             $contextid = null;
 306             $contextinstanceid = null;
 307             if (!is_null($page->context)) {
 308                 $contextid = $page->context->id;
 309                 $contextinstanceid = $page->context->instanceid;
 310                 $courseid = $page->course->id;
 311                 $coursecontext = context_course::instance($courseid);
 312             }
 313
 314             $this->M_cfg = array(
 315                 'wwwroot'               => $CFG->wwwroot,
 316                 'homeurl'               => $page->navigation->action,
 317                 'sesskey'               => sesskey(),
 318                 'sessiontimeout'        => $CFG->sessiontimeout,
 319                 'sessiontimeoutwarning' => $CFG->sessiontimeoutwarning,
 320                 'themerev'              => theme_get_revision(),
 321                 'slasharguments'        => (int)(!empty($CFG->slasharguments)),
 322                 'theme'                 => $page->theme->name,
 323                 'iconsystemmodule'      => $iconsystem->get_amd_name(),
 324                 'jsrev'                 => $this->get_jsrev(),
 325                 'admin'                 => $CFG->admin,
 326                 'svgicons'              => $page->theme->use_svg_icons(),
 327                 'usertimezone'          => usertimezone(),
 328                 'courseId'              => isset($courseid) ? (int) $courseid : 0,
 329                 'courseContextId'       => isset($coursecontext) ? $coursecontext->id : 0,
 330                 'contextid'             => $contextid,
 331                 'contextInstanceId'     => (int) $contextinstanceid,
 332                 'langrev'               => get_string_manager()->get_revision(),
 333                 'templaterev'           => $this->get_templaterev()
 334             );
 335             if ($CFG->debugdeveloper) {
 336                 $this->M_cfg['developerdebug'] = true;
 337             }
 338             if (defined('BEHAT_SITE_RUNNING')) {
 339                 $this->M_cfg['behatsiterunning'] = true;
 340             }
 341
 342         }
 343         return $this->M_cfg;
 344     }
 345
 346     /**
 347      * Initialise with the bits of JavaScript that every Moodle page should have.
 348      *
 349      * @param moodle_page $page
 350      * @param core_renderer $renderer
 351      */
 352     protected function init_requirements_data(moodle_page $page, core_renderer $renderer) {
 353         global $CFG;
 354
 355         // Init the js config.
 356         $this->get_config_for_javascript($page, $renderer);
 357
 358         // Accessibility stuff.
 359         $this->skip_link_to('maincontent', get_string('tocontent', 'access'));
 360
 361         // Add strings used on many pages.
 362         $this->string_for_js('confirmation', 'admin');
 363         $this->string_for_js('cancel', 'moodle');
 364         $this->string_for_js('yes', 'moodle');
 365
 366         // Alter links in top frame to break out of frames.
 367         if ($page->pagelayout === 'frametop') {
 368             $this->js_init_call('M.util.init_frametop');
 369         }
 370
 371         // Include block drag/drop if editing is on
 372         if ($page->user_is_editing()) {
 373             $params = array(
 374                 'regions' => $page->blocks->get_regions(),
 375                 'pagehash' => $page->get_edited_page_hash(),
 376             );
 377             if (!empty($page->cm->id)) {
 378                 $params['cmid'] = $page->cm->id;
 379             }
 380             // Strings for drag and drop.
 381             $this->strings_for_js(array('movecontent',
 382                                         'tocontent',
 383                                         'emptydragdropregion'),
 384                                   'moodle');
 385             $page->requires->yui_module('moodle-core-blocks', 'M.core_blocks.init_dragdrop', array($params), null, true);
 386             $page->requires->js_call_amd('core_block/edit', 'init', ['pagehash' => $page->get_edited_page_hash()]);
 387         }
 388
 389         // Include the YUI CSS Modules.
 390         $page->requires->set_yuicssmodules($page->theme->yuicssmodules);
 391     }
 392
 393     /**
 394      * Determine the correct JS Revision to use for this load.
 395      *
 396      * @return int the jsrev to use.
 397      */
 398     public function get_jsrev() {
 399         global $CFG;
 400
 401         if (empty($CFG->cachejs)) {
 402             $jsrev = -1;
 403         } else if (empty($CFG->jsrev)) {
 404             $jsrev = 1;
 405         } else {
 406             $jsrev = $CFG->jsrev;
 407         }
 408
 409         return $jsrev;
 410     }
 411
 412     /**
 413      * Determine the correct Template revision to use for this load.
 414      *
 415      * @return int the templaterev to use.
 416      */
 417     protected function get_templaterev() {
 418         global $CFG;
 419
 420         if (empty($CFG->cachetemplates)) {
 421             $templaterev = -1;
 422         } else if (empty($CFG->templaterev)) {
 423             $templaterev = 1;
 424         } else {
 425             $templaterev = $CFG->templaterev;
 426         }
 427
 428         return $templaterev;
 429     }
 430
 431     /**
 432      * Ensure that the specified JavaScript file is linked to from this page.
 433      *
 434      * NOTE: This function is to be used in RARE CASES ONLY, please store your JS in module.js file
 435      * and use $PAGE->requires->js_init_call() instead or use /yui/ subdirectories for YUI modules.
 436      *
 437      * By default the link is put at the end of the page, since this gives best page-load performance.
 438      *
 439      * Even if a particular script is requested more than once, it will only be linked
 440      * to once.
 441      *
 442      * @param string|moodle_url $url The path to the .js file, relative to $CFG->dirroot / $CFG->wwwroot.
 443      *      For example '/mod/mymod/customscripts.js'; use moodle_url for external scripts
 444      * @param bool $inhead initialise in head
 445      */
 446     public function js($url, $inhead = false) {
 447         if ($url == '/question/qengine.js') {
 448             debugging('The question/qengine.js has been deprecated. ' .
 449                 'Please use core_question/question_engine', DEBUG_DEVELOPER);
 450         }
 451         $url = $this->js_fix_url($url);
 452         $where = $inhead ? 'head' : 'footer';
 453         $this->jsincludes[$where][$url->out()] = $url;
 454     }
 455
 456     /**
 457      * Request inclusion of jQuery library in the page.
 458      *
 459      * NOTE: this should not be used in official Moodle distribution!
 460      *
 461      * {@see http://docs.moodle.org/dev/jQuery}
 462      */
 463     public function jquery() {
 464         $this->jquery_plugin('jquery');
 465     }
 466
 467     /**
 468      * Request inclusion of jQuery plugin.
 469      *
 470      * NOTE: this should not be used in official Moodle distribution!
 471      *
 472      * jQuery plugins are located in plugin/jquery/* subdirectory,
 473      * plugin/jquery/plugins.php lists all available plugins.
 474      *
 475      * Included core plugins:
 476      *   - jQuery UI
 477      *
 478      * Add-ons may include extra jQuery plugins in jquery/ directory,
 479      * plugins.php file defines the mapping between plugin names and
 480      * necessary page includes.
 481      *
 482      * Examples:
 483      * <code>
 484      *   // file: mod/xxx/view.php
 485      *   $PAGE->requires->jquery();
 486      *   $PAGE->requires->jquery_plugin('ui');
 487      *   $PAGE->requires->jquery_plugin('ui-css');
 488      * </code>
 489      *
 490      * <code>
 491      *   // file: theme/yyy/lib.php
 492      *   function theme_yyy_page_init(moodle_page $page) {
 493      *       $page->requires->jquery();
 494      *       $page->requires->jquery_plugin('ui');
 495      *       $page->requires->jquery_plugin('ui-css');
 496      *   }
 497      * </code>
 498      *
 499      * <code>
 500      *   // file: blocks/zzz/block_zzz.php
 501      *   public function get_required_javascript() {
 502      *       parent::get_required_javascript();
 503      *       $this->page->requires->jquery();
 504      *       $page->requires->jquery_plugin('ui');
 505      *       $page->requires->jquery_plugin('ui-css');
 506      *   }
 507      * </code>
 508      *
 509      * {@see http://docs.moodle.org/dev/jQuery}
 510      *
 511      * @param string $plugin name of the jQuery plugin as defined in jquery/plugins.php
 512      * @param string $component name of the component
 513      * @return bool success
 514      */
 515     public function jquery_plugin($plugin, $component = 'core') {
 516         global $CFG;
 517
 518         if ($this->headdone) {
 519             debugging('Can not add jQuery plugins after starting page output!');
 520             return false;
 521         }
 522
 523         if ($component !== 'core' and in_array($plugin, array('jquery', 'ui', 'ui-css'))) {
 524             debugging("jQuery plugin '$plugin' is included in Moodle core, other components can not use the same name.", DEBUG_DEVELOPER);
 525             $component = 'core';
 526         } else if ($component !== 'core' and strpos($component, '_') === false) {
 527             // Let's normalise the legacy activity names, Frankenstyle rulez!
 528             $component = 'mod_' . $component;
 529         }
 530
 531         if (empty($this->jqueryplugins) and ($component !== 'core' or $plugin !== 'jquery')) {
 532             // Make sure the jQuery itself is always loaded first,
 533             // the order of all other plugins depends on order of $PAGE_>requires->.
 534             $this->jquery_plugin('jquery', 'core');
 535         }
 536
 537         if (isset($this->jqueryplugins[$plugin])) {
 538             // No problem, we already have something, first Moodle plugin to register the jQuery plugin wins.
 539             return true;
 540         }
 541
 542         $componentdir = core_component::get_component_directory($component);
 543         if (!file_exists($componentdir) or !file_exists("$componentdir/jquery/plugins.php")) {
 544             debugging("Can not load jQuery plugin '$plugin', missing plugins.php in component '$component'.", DEBUG_DEVELOPER);
 545             return false;
 546         }
 547
 548         $plugins = array();
 549         require("$componentdir/jquery/plugins.php");
 550
 551         if (!isset($plugins[$plugin])) {
 552             debugging("jQuery plugin '$plugin' can not be found in component '$component'.", DEBUG_DEVELOPER);
 553             return false;
 554         }
 555
 556         $this->jqueryplugins[$plugin] = new stdClass();
 557         $this->jqueryplugins[$plugin]->plugin    = $plugin;
 558         $this->jqueryplugins[$plugin]->component = $component;
 559         $this->jqueryplugins[$plugin]->urls      = array();
 560
 561         foreach ($plugins[$plugin]['files'] as $file) {
 562             if ($CFG->debugdeveloper) {
 563                 if (!file_exists("$componentdir/jquery/$file")) {
 564                     debugging("Invalid file '$file' specified in jQuery plugin '$plugin' in component '$component'");
 565                     continue;
 566                 }
 567                 $file = str_replace('.min.css', '.css', $file);
 568                 $file = str_replace('.min.js', '.js', $file);
 569             }
 570             if (!file_exists("$componentdir/jquery/$file")) {
 571                 debugging("Invalid file '$file' specified in jQuery plugin '$plugin' in component '$component'");
 572                 continue;
 573             }
 574             if (!empty($CFG->slasharguments)) {
 575                 $url = new moodle_url("/theme/jquery.php");
 576                 $url->set_slashargument("/$component/$file");
 577
 578             } else {
 579                 // This is not really good, we need slasharguments for relative links, this means no caching...
 580                 $path = realpath("$componentdir/jquery/$file");
 581                 if (strpos($path, $CFG->dirroot) === 0) {
 582                     $url = $CFG->wwwroot.preg_replace('/^'.preg_quote($CFG->dirroot, '/').'/', '', $path);
 583                     // Replace all occurences of backslashes characters in url to forward slashes.
 584                     $url = str_replace('\\', '/', $url);
 585                     $url = new moodle_url($url);
 586                 } else {
 587                     // Bad luck, fix your server!
 588                     debugging("Moodle jQuery integration requires 'slasharguments' setting to be enabled.");
 589                     continue;
 590                 }
 591             }
 592             $this->jqueryplugins[$plugin]->urls[] = $url;
 593         }
 594
 595         return true;
 596     }
 597
 598     /**
 599      * Request replacement of one jQuery plugin by another.
 600      *
 601      * This is useful when themes want to replace the jQuery UI theme,
 602      * the problem is that theme can not prevent others from including the core ui-css plugin.
 603      *
 604      * Example:
 605      *  1/ generate new jQuery UI theme and place it into theme/yourtheme/jquery/
 606      *  2/ write theme/yourtheme/jquery/plugins.php
 607      *  3/ init jQuery from theme
 608      *
 609      * <code>
 610      *   // file theme/yourtheme/lib.php
 611      *   function theme_yourtheme_page_init($page) {
 612      *       $page->requires->jquery_plugin('yourtheme-ui-css', 'theme_yourtheme');
 613      *       $page->requires->jquery_override_plugin('ui-css', 'yourtheme-ui-css');
 614      *   }
 615      * </code>
 616      *
 617      * This code prevents loading of standard 'ui-css' which my be requested by other plugins,
 618      * the 'yourtheme-ui-css' gets loaded only if some other code requires jquery.
 619      *
 620      * {@see http://docs.moodle.org/dev/jQuery}
 621      *
 622      * @param string $oldplugin original plugin
 623      * @param string $newplugin the replacement
 624      */
 625     public function jquery_override_plugin($oldplugin, $newplugin) {
 626         if ($this->headdone) {
 627             debugging('Can not override jQuery plugins after starting page output!');
 628             return;
 629         }
 630         $this->jquerypluginoverrides[$oldplugin] = $newplugin;
 631     }
 632
 633     /**
 634      * Return jQuery related markup for page start.
 635      * @return string
 636      */
 637     protected function get_jquery_headcode() {
 638         if (empty($this->jqueryplugins['jquery'])) {
 639             // If nobody requested jQuery then do not bother to load anything.
 640             // This may be useful for themes that want to override 'ui-css' only if requested by something else.
 641             return '';
 642         }
 643
 644         $included = array();
 645         $urls = array();
 646
 647         foreach ($this->jqueryplugins as $name => $unused) {
 648             if (isset($included[$name])) {
 649                 continue;
 650             }
 651             if (array_key_exists($name, $this->jquerypluginoverrides)) {
 652                 // The following loop tries to resolve the replacements,
 653                 // use max 100 iterations to prevent infinite loop resulting
 654                 // in blank page.
 655                 $cyclic = true;
 656                 $oldname = $name;
 657                 for ($i=0; $i<100; $i++) {
 658                     $name = $this->jquerypluginoverrides[$name];
 659                     if (!array_key_exists($name, $this->jquerypluginoverrides)) {
 660                         $cyclic = false;
 661                         break;
 662                     }
 663                 }
 664                 if ($cyclic) {
 665                     // We can not do much with cyclic references here, let's use the old plugin.
 666                     $name = $oldname;
 667                     debugging("Cyclic overrides detected for jQuery plugin '$name'");
 668
 669                 } else if (empty($name)) {
 670                     // Developer requested removal of the plugin.
 671                     continue;
 672
 673                 } else if (!isset($this->jqueryplugins[$name])) {
 674                     debugging("Unknown jQuery override plugin '$name' detected");
 675                     $name = $oldname;
 676
 677                 } else if (isset($included[$name])) {
 678                     // The plugin was already included, easy.
 679                     continue;
 680                 }
 681             }
 682
 683             $plugin = $this->jqueryplugins[$name];
 684             $urls = array_merge($urls, $plugin->urls);
 685             $included[$name] = true;
 686         }
 687
 688         $output = '';
 689         $attributes = array('rel' => 'stylesheet', 'type' => 'text/css');
 690         foreach ($urls as $url) {
 691             if (preg_match('/\.js$/', $url)) {
 692                 $output .= html_writer::script('', $url);
 693             } else if (preg_match('/\.css$/', $url)) {
 694                 $attributes['href'] = $url;
 695                 $output .= html_writer::empty_tag('link', $attributes) . "\n";
 696             }
 697         }
 698
 699         return $output;
 700     }
 701
 702     /**
 703      * Returns the actual url through which a JavaScript file is served.
 704      *
 705      * @param moodle_url|string $url full moodle url, or shortened path to script.
 706      * @throws coding_exception if the given $url isn't a shortened url starting with / or a moodle_url instance.
 707      * @return moodle_url
 708      */
 709     protected function js_fix_url($url) {
 710         global $CFG;
 711
 712         if ($url instanceof moodle_url) {
 713             // If the URL is external to Moodle, it won't be handled by Moodle (!).
 714             if ($url->is_local_url()) {
 715                 $localurl = $url->out_as_local_url();
 716                 // Check if the URL points to a Moodle PHP resource.
 717                 if (strpos($localurl, '.php') !== false) {
 718                     // It's a Moodle PHP resource e.g. a resource already served by the proper Moodle Handler.
 719                     return $url;
 720                 }
 721                 // It's a local resource: we need to further examine it.
 722                 return $this->js_fix_url($url->out_as_local_url(false));
 723             }
 724             // The URL is not a Moodle resource.
 725             return $url;
 726         } else if (null !== $url && strpos($url, '/') === 0) {
 727             // Fix the admin links if needed.
 728             if ($CFG->admin !== 'admin') {
 729                 if (strpos($url, "/admin/") === 0) {
 730                     $url = preg_replace("|^/admin/|", "/$CFG->admin/", $url);
 731                 }
 732             }
 733             if (debugging()) {
 734                 // Check file existence only when in debug mode.
 735                 if (!file_exists($CFG->dirroot . strtok($url, '?'))) {
 736                     throw new coding_exception('Attempt to require a JavaScript file that does not exist.', $url);
 737                 }
 738             }
 739             if (substr($url, -3) === '.js') {
 740                 $jsrev = $this->get_jsrev();
 741                 if (empty($CFG->slasharguments)) {
 742                     return new moodle_url('/lib/javascript.php', ['rev' => $jsrev, 'jsfile' => $url]);
 743                 } else {
 744                     $returnurl = new moodle_url('/lib/javascript.php');
 745                     $returnurl->set_slashargument('/'.$jsrev.$url);
 746                     return $returnurl;
 747                 }
 748             } else {
 749                 return new moodle_url($url);
 750             }
 751         } else {
 752             throw new coding_exception('Invalid JS url, it has to be shortened url starting with / or moodle_url instance.', $url);
 753         }
 754     }
 755
 756     /**
 757      * Find out if JS module present and return details.
 758      *
 759      * @param string $component name of component in frankenstyle, ex: core_group, mod_forum
 760      * @return array description of module or null if not found
 761      */
 762     protected function find_module($component) {
 763         global $CFG, $PAGE;
 764
 765         $module = null;
 766
 767         if (strpos($component, 'core_') === 0) {
 768             // Must be some core stuff - list here is not complete, this is just the stuff used from multiple places
 769             // so that we do nto have to repeat the definition of these modules over and over again.
 770             switch($component) {
 771                 case 'core_filepicker':
 772                     $module = array('name'     => 'core_filepicker',
 773                                     'fullpath' => '/repository/filepicker.js',
 774                                     'requires' => array(
 775                                         'base', 'node', 'node-event-simulate', 'json', 'async-queue', 'io-base', 'io-upload-iframe', 'io-form',
 776                                         'yui2-treeview', 'panel', 'cookie', 'datatable', 'datatable-sort', 'resize-plugin', 'dd-plugin',
 777                                         'escape', 'moodle-core_filepicker', 'moodle-core-notification-dialogue'
 778                                     ),
 779                                     'strings'  => array(array('lastmodified', 'moodle'), array('name', 'moodle'), array('type', 'repository'), array('size', 'repository'),
 780                                                         array('invalidjson', 'repository'), array('error', 'moodle'), array('info', 'moodle'),
 781                                                         array('nofilesattached', 'repository'), array('filepicker', 'repository'), array('logout', 'repository'),
 782                                                         array('nofilesavailable', 'repository'), array('norepositoriesavailable', 'repository'),
 783                                                         array('fileexistsdialogheader', 'repository'), array('fileexistsdialog_editor', 'repository'),
 784                                                         array('fileexistsdialog_filemanager', 'repository'), array('renameto', 'repository'),
 785                                                         array('referencesexist', 'repository'), array('select', 'repository')
 786                                                     ));
 787                     break;
 788                 case 'core_comment':
 789                     $module = array('name'     => 'core_comment',
 790                                     'fullpath' => '/comment/comment.js',
 791                                     'requires' => array('base', 'io-base', 'node', 'json', 'yui2-animation', 'overlay', 'escape'),
 792                                     'strings' => array(array('confirmdeletecomments', 'admin'), array('yes', 'moodle'), array('no', 'moodle'))
 793                                 );
 794                     break;
 795                 case 'core_role':
 796                     $module = array('name'     => 'core_role',
 797                                     'fullpath' => '/admin/roles/module.js',
 798                                     'requires' => array('node', 'cookie'));
 799                     break;
 800                 case 'core_completion':
 801                     break;
 802                 case 'core_message':
 803                     $module = array('name'     => 'core_message',
 804                                     'requires' => array('base', 'node', 'event', 'node-event-simulate'),
 805                                     'fullpath' => '/message/module.js');
 806                     break;
 807                 case 'core_group':
 808                     $module = array('name'     => 'core_group',
 809                                     'fullpath' => '/group/module.js',
 810                                     'requires' => array('node', 'overlay', 'event-mouseenter'));
 811                     break;
 812                 case 'core_question_engine':
 813                     $module = array('name'     => 'core_question_engine',
 814                                     'fullpath' => '/question/qengine.js',
 815                                     'requires' => array('node', 'event'));
 816                     break;
 817                 case 'core_rating':
 818                     $module = array('name'     => 'core_rating',
 819                                     'fullpath' => '/rating/module.js',
 820                                     'requires' => array('node', 'event', 'overlay', 'io-base', 'json'));
 821                     break;
 822                 case 'core_dndupload':
 823                     $module = array('name'     => 'core_dndupload',
 824                                     'fullpath' => '/lib/form/dndupload.js',
 825                                     'requires' => array('node', 'event', 'json', 'core_filepicker'),
 826                                     'strings'  => array(array('uploadformlimit', 'moodle'), array('droptoupload', 'moodle'), array('maxfilesreached', 'moodle'),
 827                                                         array('dndenabled_inbox', 'moodle'), array('fileexists', 'moodle'), array('maxbytesfile', 'error'),
 828                                                         array('sizegb', 'moodle'), array('sizemb', 'moodle'), array('sizekb', 'moodle'), array('sizeb', 'moodle'),
 829                                                         array('maxareabytesreached', 'moodle'), array('serverconnection', 'error'),
 830                                                         array('changesmadereallygoaway', 'moodle'), array('complete', 'moodle')
 831                                                     ));
 832                     break;
 833             }
 834
 835         } else {
 836             if ($dir = core_component::get_component_directory($component)) {
 837                 if (file_exists("$dir/module.js")) {
 838                     if (strpos($dir, $CFG->dirroot.'/') === 0) {
 839                         $dir = substr($dir, strlen($CFG->dirroot));
 840                         $module = array('name'=>$component, 'fullpath'=>"$dir/module.js", 'requires' => array());
 841                     }
 842                 }
 843             }
 844         }
 845
 846         return $module;
 847     }
 848
 849     /**
 850      * Append YUI3 module to default YUI3 JS loader.
 851      * The structure of module array is described at {@link http://developer.yahoo.com/yui/3/yui/}
 852      *
 853      * @param string|array $module name of module (details are autodetected), or full module specification as array
 854      * @return void
 855      */
 856     public function js_module($module) {
 857         global $CFG;
 858
 859         if (empty($module)) {
 860             throw new coding_exception('Missing YUI3 module name or full description.');
 861         }
 862
 863         if (is_string($module)) {
 864             $module = $this->find_module($module);
 865         }
 866
 867         if (empty($module) or empty($module['name']) or empty($module['fullpath'])) {
 868             throw new coding_exception('Missing YUI3 module details.');
 869         }
 870
 871         $module['fullpath'] = $this->js_fix_url($module['fullpath'])->out(false);
 872         // Add all needed strings.
 873         if (!empty($module['strings'])) {
 874             foreach ($module['strings'] as $string) {
 875                 $identifier = $string[0];
 876                 $component = isset($string[1]) ? $string[1] : 'moodle';
 877                 $a = isset($string[2]) ? $string[2] : null;
 878                 $this->string_for_js($identifier, $component, $a);
 879             }
 880         }
 881         unset($module['strings']);
 882
 883         // Process module requirements and attempt to load each. This allows
 884         // moodle modules to require each other.
 885         if (!empty($module['requires'])){
 886             foreach ($module['requires'] as $requirement) {
 887                 $rmodule = $this->find_module($requirement);
 888                 if (is_array($rmodule)) {
 889                     $this->js_module($rmodule);
 890                 }
 891             }
 892         }
 893
 894         if ($this->headdone) {
 895             $this->extramodules[$module['name']] = $module;
 896         } else {
 897             $this->YUI_config->add_module_config($module['name'], $module);
 898         }
 899     }
 900
 901     /**
 902      * Returns true if the module has already been loaded.
 903      *
 904      * @param string|array $module
 905      * @return bool True if the module has already been loaded
 906      */
 907     protected function js_module_loaded($module) {
 908         if (is_string($module)) {
 909             $modulename = $module;
 910         } else {
 911             $modulename = $module['name'];
 912         }
 913         return array_key_exists($modulename, $this->YUI_config->modules) ||
 914                array_key_exists($modulename, $this->extramodules);
 915     }
 916
 917     /**
 918      * Ensure that the specified CSS file is linked to from this page.
 919      *
 920      * Because stylesheet links must go in the <head> part of the HTML, you must call
 921      * this function before {@link get_head_code()} is called. That normally means before
 922      * the call to print_header. If you call it when it is too late, an exception
 923      * will be thrown.
 924      *
 925      * Even if a particular style sheet is requested more than once, it will only
 926      * be linked to once.
 927      *
 928      * Please note use of this feature is strongly discouraged,
 929      * it is suitable only for places where CSS is submitted directly by teachers.
 930      * (Students must not be allowed to submit any external CSS because it may
 931      * contain embedded javascript!). Example of correct use is mod/data.
 932      *
 933      * @param string $stylesheet The path to the .css file, relative to $CFG->wwwroot.
 934      *   For example:
 935      *      $PAGE->requires->css('mod/data/css.php?d='.$data->id);
 936      */
 937     public function css($stylesheet) {
 938         global $CFG;
 939
 940         if ($this->headdone) {
 941             throw new coding_exception('Cannot require a CSS file after &lt;head> has been printed.', $stylesheet);
 942         }
 943
 944         if ($stylesheet instanceof moodle_url) {
 945             // ok
 946         } else if (strpos($stylesheet, '/') === 0) {
 947             $stylesheet = new moodle_url($stylesheet);
 948         } else {
 949             throw new coding_exception('Invalid stylesheet parameter.', $stylesheet);
 950         }
 951
 952         $this->cssurls[$stylesheet->out()] = $stylesheet;
 953     }
 954
 955     /**
 956      * Add theme stylesheet to page - do not use from plugin code,
 957      * this should be called only from the core renderer!
 958      *
 959      * @param moodle_url $stylesheet
 960      * @return void
 961      */
 962     public function css_theme(moodle_url $stylesheet) {
 963         $this->cssthemeurls[] = $stylesheet;
 964     }
 965
 966     /**
 967      * Ensure that a skip link to a given target is printed at the top of the <body>.
 968      *
 969      * You must call this function before {@link get_top_of_body_code()}, (if not, an exception
 970      * will be thrown). That normally means you must call this before the call to print_header.
 971      *
 972      * If you ask for a particular skip link to be printed, it is then your responsibility
 973      * to ensure that the appropriate <a name="..."> tag is printed in the body of the
 974      * page, so that the skip link goes somewhere.
 975      *
 976      * Even if a particular skip link is requested more than once, only one copy of it will be output.
 977      *
 978      * @param string $target the name of anchor this link should go to. For example 'maincontent'.
 979      * @param string $linktext The text to use for the skip link. Normally get_string('skipto', 'access', ...);
 980      */
 981     public function skip_link_to($target, $linktext) {
 982         if ($this->topofbodydone) {
 983             debugging('Page header already printed, can not add skip links any more, code needs to be fixed.');
 984             return;
 985         }
 986         $this->skiplinks[$target] = $linktext;
 987     }
 988
 989     /**
 990      * !!!DEPRECATED!!! please use js_init_call() if possible
 991      * Ensure that the specified JavaScript function is called from an inline script
 992      * somewhere on this page.
 993      *
 994      * By default the call will be put in a script tag at the
 995      * end of the page after initialising Y instance, since this gives best page-load
 996      * performance and allows you to use YUI3 library.
 997      *
 998      * If you request that a particular function is called several times, then
 999      * that is what will happen (unlike linking to a CSS or JS file, where only
1000      * one link will be output).
1001      *
1002      * The main benefit of the method is the automatic encoding of all function parameters.
1003      *
1004      * @deprecated
1005      *
1006      * @param string $function the name of the JavaScritp function to call. Can
1007      *      be a compound name like 'Y.Event.purgeElement'. Can also be
1008      *      used to create and object by using a 'function name' like 'new user_selector'.
1009      * @param array $arguments and array of arguments to be passed to the function.
1010      *      When generating the function call, this will be escaped using json_encode,
1011      *      so passing objects and arrays should work.
1012      * @param bool $ondomready If tru the function is only called when the dom is
1013      *      ready for manipulation.
1014      * @param int $delay The delay before the function is called.
1015      */
1016     public function js_function_call($function, array $arguments = null, $ondomready = false, $delay = 0) {
1017         $where = $ondomready ? 'ondomready' : 'normal';
1018         $this->jscalls[$where][] = array($function, $arguments, $delay);
1019     }
1020
1021     /**
1022      * This function appends a block of code to the AMD specific javascript block executed
1023      * in the page footer, just after loading the requirejs library.
1024      *
1025      * The code passed here can rely on AMD module loading, e.g. require('jquery', function($) {...});
1026      *
1027      * @param string $code The JS code to append.
1028      */
1029     public function js_amd_inline($code) {
1030         $this->amdjscode[] = $code;
1031     }
1032
1033     /**
1034      * Load an AMD module and eventually call its method.
1035      *
1036      * This function creates a minimal inline JS snippet that requires an AMD module and eventually calls a single
1037      * function from the module with given arguments. If it is called multiple times, it will be create multiple
1038      * snippets.
1039      *
1040      * @param string $fullmodule The name of the AMD module to load, formatted as <component name>/<module name>.
1041      * @param string $func Optional function from the module to call, defaults to just loading the AMD module.
1042      * @param array $params The params to pass to the function (will be serialized into JSON).
1043      */
1044     public function js_call_amd($fullmodule, $func = null, $params = array()) {
1045         global $CFG;
1046
1047         $modulepath = explode('/', $fullmodule);
1048
1049         $modname = clean_param(array_shift($modulepath), PARAM_COMPONENT);
1050         foreach ($modulepath as $module) {
1051             $modname .= '/' . clean_param($module, PARAM_ALPHANUMEXT);
1052         }
1053
1054         $functioncode = [];
1055         if ($func !== null) {
1056             $func = clean_param($func, PARAM_ALPHANUMEXT);
1057
1058             $jsonparams = array();
1059             foreach ($params as $param) {
1060                 $jsonparams[] = json_encode($param);
1061             }
1062             $strparams = implode(', ', $jsonparams);
1063             if ($CFG->debugdeveloper) {
1064                 $toomanyparamslimit = 1024;
1065                 if (strlen($strparams) > $toomanyparamslimit) {
1066                     debugging('Too much data passed as arguments to js_call_amd("' . $fullmodule . '", "' . $func .
1067                         '"). Generally there are better ways to pass lots of data from PHP to JavaScript, for example via Ajax, ' .
1068                         'data attributes, ... . This warning is triggered if the argument string becomes longer than ' .
1069                         $toomanyparamslimit . ' characters.', DEBUG_DEVELOPER);
1070                 }
1071             }
1072
1073             $functioncode[] = "amd.{$func}({$strparams});";
1074         }
1075
1076         $functioncode[] = "M.util.js_complete('{$modname}');";
1077
1078         $initcode = implode(' ', $functioncode);
1079         $js = "M.util.js_pending('{$modname}'); require(['{$modname}'], function(amd) {{$initcode}});";
1080
1081         $this->js_amd_inline($js);
1082     }
1083
1084     /**
1085      * Creates a JavaScript function call that requires one or more modules to be loaded.
1086      *
1087      * This function can be used to include all of the standard YUI module types within JavaScript:
1088      *     - YUI3 modules    [node, event, io]
1089      *     - YUI2 modules    [yui2-*]
1090      *     - Moodle modules  [moodle-*]
1091      *     - Gallery modules [gallery-*]
1092      *
1093      * Before writing new code that makes extensive use of YUI, you should consider it's replacement AMD/JQuery.
1094      * @see js_call_amd()
1095      *
1096      * @param array|string $modules One or more modules
1097      * @param string $function The function to call once modules have been loaded
1098      * @param array $arguments An array of arguments to pass to the function
1099      * @param string $galleryversion Deprecated: The gallery version to use
1100      * @param bool $ondomready
1101      */
1102     public function yui_module($modules, $function, array $arguments = null, $galleryversion = null, $ondomready = false) {
1103         if (!is_array($modules)) {
1104             $modules = array($modules);
1105         }
1106
1107         if ($galleryversion != null) {
1108             debugging('The galleryversion parameter to yui_module has been deprecated since Moodle 2.3.');
1109         }
1110
1111         $jscode = 'Y.use('.join(',', array_map('json_encode', convert_to_array($modules))).',function() {'.js_writer::function_call($function, $arguments).'});';
1112         if ($ondomready) {
1113             $jscode = "Y.on('domready', function() { $jscode });";
1114         }
1115         $this->jsinitcode[] = $jscode;
1116     }
1117
1118     /**
1119      * Set the CSS Modules to be included from YUI.
1120      *
1121      * @param array $modules The list of YUI CSS Modules to include.
1122      */
1123     public function set_yuicssmodules(array $modules = array()) {
1124         $this->yuicssmodules = $modules;
1125     }
1126
1127     /**
1128      * Ensure that the specified JavaScript function is called from an inline script
1129      * from page footer.
1130      *
1131      * @param string $function the name of the JavaScritp function to with init code,
1132      *      usually something like 'M.mod_mymodule.init'
1133      * @param array $extraarguments and array of arguments to be passed to the function.
1134      *      The first argument is always the YUI3 Y instance with all required dependencies
1135      *      already loaded.
1136      * @param bool $ondomready wait for dom ready (helps with some IE problems when modifying DOM)
1137      * @param array $module JS module specification array
1138      */
1139     public function js_init_call($function, array $extraarguments = null, $ondomready = false, array $module = null) {
1140         $jscode = js_writer::function_call_with_Y($function, $extraarguments);
1141         if (!$module) {
1142             // Detect module automatically.
1143             if (preg_match('/M\.([a-z0-9]+_[^\.]+)/', $function, $matches)) {
1144                 $module = $this->find_module($matches[1]);
1145             }
1146         }
1147
1148         $this->js_init_code($jscode, $ondomready, $module);
1149     }
1150
1151     /**
1152      * Add short static javascript code fragment to page footer.
1153      * This is intended primarily for loading of js modules and initialising page layout.
1154      * Ideally the JS code fragment should be stored in plugin renderer so that themes
1155      * may override it.
1156      *
1157      * @param string $jscode
1158      * @param bool $ondomready wait for dom ready (helps with some IE problems when modifying DOM)
1159      * @param array $module JS module specification array
1160      */
1161     public function js_init_code($jscode, $ondomready = false, array $module = null) {
1162         $jscode = trim($jscode, " ;\n"). ';';
1163
1164         $uniqid = html_writer::random_id();
1165         $startjs = " M.util.js_pending('" . $uniqid . "');";
1166         $endjs = " M.util.js_complete('" . $uniqid . "');";
1167
1168         if ($module) {
1169             $this->js_module($module);
1170             $modulename = $module['name'];
1171             $jscode = "$startjs Y.use('$modulename', function(Y) { $jscode $endjs });";
1172         }
1173
1174         if ($ondomready) {
1175             $jscode = "$startjs Y.on('domready', function() { $jscode $endjs });";
1176         }
1177
1178         $this->jsinitcode[] = $jscode;
1179     }
1180
1181     /**
1182      * Make a language string available to JavaScript.
1183      *
1184      * All the strings will be available in a M.str object in the global namespace.
1185      * So, for example, after a call to $PAGE->requires->string_for_js('course', 'moodle');
1186      * then the JavaScript variable M.str.moodle.course will be 'Course', or the
1187      * equivalent in the current language.
1188      *
1189      * The arguments to this function are just like the arguments to get_string
1190      * except that $component is not optional, and there are some aspects to consider
1191      * when the string contains {$a} placeholder.
1192      *
1193      * If the string does not contain any {$a} placeholder, you can simply use
1194      * M.str.component.identifier to obtain it. If you prefer, you can call
1195      * M.util.get_string(identifier, component) to get the same result.
1196      *
1197      * If you need to use {$a} placeholders, there are two options. Either the
1198      * placeholder should be substituted in PHP on server side or it should
1199      * be substituted in Javascript at client side.
1200      *
1201      * To substitute the placeholder at server side, just provide the required
1202      * value for the placeholder when you require the string. Because each string
1203      * is only stored once in the JavaScript (based on $identifier and $module)
1204      * you cannot get the same string with two different values of $a. If you try,
1205      * an exception will be thrown. Once the placeholder is substituted, you can
1206      * use M.str or M.util.get_string() as shown above:
1207      *
1208      *     // Require the string in PHP and replace the placeholder.
1209      *     $PAGE->requires->string_for_js('fullnamedisplay', 'moodle', $USER);
1210      *     // Use the result of the substitution in Javascript.
1211      *     alert(M.str.moodle.fullnamedisplay);
1212      *
1213      * To substitute the placeholder at client side, use M.util.get_string()
1214      * function. It implements the same logic as {@link get_string()}:
1215      *
1216      *     // Require the string in PHP but keep {$a} as it is.
1217      *     $PAGE->requires->string_for_js('fullnamedisplay', 'moodle');
1218      *     // Provide the values on the fly in Javascript.
1219      *     user = { firstname : 'Harry', lastname : 'Potter' }
1220      *     alert(M.util.get_string('fullnamedisplay', 'moodle', user);
1221      *
1222      * If you do need the same string expanded with different $a values in PHP
1223      * on server side, then the solution is to put them in your own data structure
1224      * (e.g. and array) that you pass to JavaScript with {@link data_for_js()}.
1225      *
1226      * @param string $identifier the desired string.
1227      * @param string $component the language file to look in.
1228      * @param mixed $a any extra data to add into the string (optional).
1229      */
1230     public function string_for_js($identifier, $component, $a = null) {
1231         if (!$component) {
1232             throw new coding_exception('The $component parameter is required for page_requirements_manager::string_for_js().');
1233         }
1234         if (isset($this->stringsforjs_as[$component][$identifier]) and $this->stringsforjs_as[$component][$identifier] !== $a) {
1235             throw new coding_exception("Attempt to re-define already required string '$identifier' " .
1236                     "from lang file '$component' with different \$a parameter?");
1237         }
1238         if (!isset($this->stringsforjs[$component][$identifier])) {
1239             $this->stringsforjs[$component][$identifier] = new lang_string($identifier, $component, $a);
1240             $this->stringsforjs_as[$component][$identifier] = $a;
1241         }
1242     }
1243
1244     /**
1245      * Make an array of language strings available for JS.
1246      *
1247      * This function calls the above function {@link string_for_js()} for each requested
1248      * string in the $identifiers array that is passed to the argument for a single module
1249      * passed in $module.
1250      *
1251      * <code>
1252      * $PAGE->requires->strings_for_js(array('one', 'two', 'three'), 'mymod', array('a', null, 3));
1253      *
1254      * // The above is identical to calling:
1255      *
1256      * $PAGE->requires->string_for_js('one', 'mymod', 'a');
1257      * $PAGE->requires->string_for_js('two', 'mymod');
1258      * $PAGE->requires->string_for_js('three', 'mymod', 3);
1259      * </code>
1260      *
1261      * @param array $identifiers An array of desired strings
1262      * @param string $component The module to load for
1263      * @param mixed $a This can either be a single variable that gets passed as extra
1264      *         information for every string or it can be an array of mixed data where the
1265      *         key for the data matches that of the identifier it is meant for.
1266      *
1267      */
1268     public function strings_for_js($identifiers, $component, $a = null) {
1269         foreach ($identifiers as $key => $identifier) {
1270             if (is_array($a) && array_key_exists($key, $a)) {
1271                 $extra = $a[$key];
1272             } else {
1273                 $extra = $a;
1274             }
1275             $this->string_for_js($identifier, $component, $extra);
1276         }
1277     }
1278
1279     /**
1280      * !!!!!!DEPRECATED!!!!!! please use js_init_call() for everything now.
1281      *
1282      * Make some data from PHP available to JavaScript code.
1283      *
1284      * For example, if you call
1285      * <pre>
1286      *      $PAGE->requires->data_for_js('mydata', array('name' => 'Moodle'));
1287      * </pre>
1288      * then in JavsScript mydata.name will be 'Moodle'.
1289      *
1290      * @deprecated
1291      * @param string $variable the the name of the JavaScript variable to assign the data to.
1292      *      Will probably work if you use a compound name like 'mybuttons.button[1]', but this
1293      *      should be considered an experimental feature.
1294      * @param mixed $data The data to pass to JavaScript. This will be escaped using json_encode,
1295      *      so passing objects and arrays should work.
1296      * @param bool $inhead initialise in head
1297      * @return void
1298      */
1299     public function data_for_js($variable, $data, $inhead=false) {
1300         $where = $inhead ? 'head' : 'footer';
1301         $this->jsinitvariables[$where][] = array($variable, $data);
1302     }
1303
1304     /**
1305      * Creates a YUI event handler.
1306      *
1307      * @param mixed $selector standard YUI selector for elements, may be array or string, element id is in the form "#idvalue"
1308      * @param string $event A valid DOM event (click, mousedown, change etc.)
1309      * @param string $function The name of the function to call
1310      * @param array  $arguments An optional array of argument parameters to pass to the function
1311      */
1312     public function event_handler($selector, $event, $function, array $arguments = null) {
1313         $this->eventhandlers[] = array('selector'=>$selector, 'event'=>$event, 'function'=>$function, 'arguments'=>$arguments);
1314     }
1315
1316     /**
1317      * Returns code needed for registering of event handlers.
1318      * @return string JS code
1319      */
1320     protected function get_event_handler_code() {
1321         $output = '';
1322         foreach ($this->eventhandlers as $h) {
1323             $output .= js_writer::event_handler($h['selector'], $h['event'], $h['function'], $h['arguments']);
1324         }
1325         return $output;
1326     }
1327
1328     /**
1329      * Get the inline JavaScript code that need to appear in a particular place.
1330      * @param bool $ondomready
1331      * @return string
1332      */
1333     protected function get_javascript_code($ondomready) {
1334         $where = $ondomready ? 'ondomready' : 'normal';
1335         $output = '';
1336         if ($this->jscalls[$where]) {
1337             foreach ($this->jscalls[$where] as $data) {
1338                 $output .= js_writer::function_call($data[0], $data[1], $data[2]);
1339             }
1340             if (!empty($ondomready)) {
1341                 $output = "    Y.on('domready', function() {\n$output\n});";
1342             }
1343         }
1344         return $output;
1345     }
1346
1347     /**
1348      * Returns js code to be executed when Y is available.
1349      * @return string
1350      */
1351     protected function get_javascript_init_code() {
1352         if (count($this->jsinitcode)) {
1353             return implode("\n", $this->jsinitcode) . "\n";
1354         }
1355         return '';
1356     }
1357
1358     /**
1359      * Returns js code to load amd module loader, then insert inline script tags
1360      * that contain require() calls using RequireJS.
1361      * @return string
1362      */
1363     protected function get_amd_footercode() {
1364         global $CFG;
1365         $output = '';
1366
1367         // We will cache JS if cachejs is not set, or it is true.
1368         $cachejs = !isset($CFG->cachejs) || $CFG->cachejs;
1369         $jsrev = $this->get_jsrev();
1370
1371         $jsloader = new moodle_url('/lib/javascript.php');
1372         $jsloader->set_slashargument('/' . $jsrev . '/');
1373         $requirejsloader = new moodle_url('/lib/requirejs.php');
1374         $requirejsloader->set_slashargument('/' . $jsrev . '/');
1375
1376         $requirejsconfig = file_get_contents($CFG->dirroot . '/lib/requirejs/moodle-config.js');
1377
1378         // No extension required unless slash args is disabled.
1379         $jsextension = '.js';
1380         if (!empty($CFG->slasharguments)) {
1381             $jsextension = '';
1382         }
1383
1384         $minextension = '.min';
1385         if (!$cachejs) {
1386             $minextension = '';
1387         }
1388
1389         $requirejsconfig = str_replace('[BASEURL]', $requirejsloader, $requirejsconfig);
1390         $requirejsconfig = str_replace('[JSURL]', $jsloader, $requirejsconfig);
1391         $requirejsconfig = str_replace('[JSMIN]', $minextension, $requirejsconfig);
1392         $requirejsconfig = str_replace('[JSEXT]', $jsextension, $requirejsconfig);
1393
1394         $output .= html_writer::script($requirejsconfig);
1395         if ($cachejs) {
1396             $output .= html_writer::script('', $this->js_fix_url('/lib/requirejs/require.min.js'));
1397         } else {
1398             $output .= html_writer::script('', $this->js_fix_url('/lib/requirejs/require.js'));
1399         }
1400
1401         // First include must be to a module with no dependencies, this prevents multiple requests.
1402         $prefix = <<<EOF
1403 M.util.js_pending("core/first");
1404 require(['core/first'], function() {
1405
1406 EOF;
1407
1408         if (during_initial_install()) {
1409             // Do not run a prefetch during initial install as the DB is not available to service WS calls.
1410             $prefetch = '';
1411         } else {
1412             $prefetch = "require(['core/prefetch'])\n";
1413         }
1414
1415         $suffix = <<<EOF
1416
1417     M.util.js_complete("core/first");
1418 });
1419 EOF;
1420
1421         $output .= html_writer::script($prefix . $prefetch . implode(";\n", $this->amdjscode) . $suffix);
1422         return $output;
1423     }
1424
1425     /**
1426      * Returns basic YUI3 CSS code.
1427      *
1428      * @return string
1429      */
1430     protected function get_yui3lib_headcss() {
1431         global $CFG;
1432
1433         $yuiformat = '-min';
1434         if ($this->yui3loader->filter === 'RAW') {
1435             $yuiformat = '';
1436         }
1437
1438         $code = '';
1439         if ($this->yui3loader->combine) {
1440             if (!empty($this->yuicssmodules)) {
1441                 $modules = array();
1442                 foreach ($this->yuicssmodules as $module) {
1443                     $modules[] = "$CFG->yui3version/$module/$module-min.css";
1444                 }
1445                 $code .= '<link rel="stylesheet" type="text/css" href="'.$this->yui3loader->comboBase.implode('&amp;', $modules).'" />';
1446             }
1447             $code .= '<link rel="stylesheet" type="text/css" href="'.$this->yui3loader->local_comboBase.'rollup/'.$CFG->yui3version.'/yui-moodlesimple' . $yuiformat . '.css" />';
1448
1449         } else {
1450             if (!empty($this->yuicssmodules)) {
1451                 foreach ($this->yuicssmodules as $module) {
1452                     $code .= '<link rel="stylesheet" type="text/css" href="'.$this->yui3loader->base.$module.'/'.$module.'-min.css" />';
1453                 }
1454             }
1455             $code .= '<link rel="stylesheet" type="text/css" href="'.$this->yui3loader->local_comboBase.'rollup/'.$CFG->yui3version.'/yui-moodlesimple' . $yuiformat . '.css" />';
1456         }
1457
1458         if ($this->yui3loader->filter === 'RAW') {
1459             $code = str_replace('-min.css', '.css', $code);
1460         } else if ($this->yui3loader->filter === 'DEBUG') {
1461             $code = str_replace('-min.css', '.css', $code);
1462         }
1463         return $code;
1464     }
1465
1466     /**
1467      * Returns basic YUI3 JS loading code.
1468      *
1469      * @return string
1470      */
1471     protected function get_yui3lib_headcode() {
1472         global $CFG;
1473
1474         $jsrev = $this->get_jsrev();
1475
1476         $yuiformat = '-min';
1477         if ($this->yui3loader->filter === 'RAW') {
1478             $yuiformat = '';
1479         }
1480
1481         $format = '-min';
1482         if ($this->YUI_config->groups['moodle']['filter'] === 'DEBUG') {
1483             $format = '-debug';
1484         }
1485
1486         $rollupversion = $CFG->yui3version;
1487         if (!empty($CFG->yuipatchlevel)) {
1488             $rollupversion .= '_' . $CFG->yuipatchlevel;
1489         }
1490
1491         $baserollups = array(
1492             'rollup/' . $rollupversion . "/yui-moodlesimple{$yuiformat}.js",
1493         );
1494
1495         if ($this->yui3loader->combine) {
1496             return '<script src="' .
1497                     $this->yui3loader->local_comboBase .
1498                     implode('&amp;', $baserollups) .
1499                     '"></script>';
1500         } else {
1501             $code = '';
1502             foreach ($baserollups as $rollup) {
1503                 $code .= '<script src="'.$this->yui3loader->local_comboBase.$rollup.'"></script>';
1504             }
1505             return $code;
1506         }
1507
1508     }
1509
1510     /**
1511      * Returns html tags needed for inclusion of theme CSS.
1512      *
1513      * @return string
1514      */
1515     protected function get_css_code() {
1516         // First of all the theme CSS, then any custom CSS
1517         // Please note custom CSS is strongly discouraged,
1518         // because it can not be overridden by themes!
1519         // It is suitable only for things like mod/data which accepts CSS from teachers.
1520         $attributes = array('rel'=>'stylesheet', 'type'=>'text/css');
1521
1522         // Add the YUI code first. We want this to be overridden by any Moodle CSS.
1523         $code = $this->get_yui3lib_headcss();
1524
1525         // This line of code may look funny but it is currently required in order
1526         // to avoid MASSIVE display issues in Internet Explorer.
1527         // As of IE8 + YUI3.1.1 the reference stylesheet (firstthemesheet) gets
1528         // ignored whenever another resource is added until such time as a redraw
1529         // is forced, usually by moving the mouse over the affected element.
1530         $code .= html_writer::tag('script', '/** Required in order to fix style inclusion problems in IE with YUI **/', array('id'=>'firstthemesheet', 'type'=>'text/css'));
1531
1532         $urls = $this->cssthemeurls + $this->cssurls;
1533         foreach ($urls as $url) {
1534             $attributes['href'] = $url;
1535             $code .= html_writer::empty_tag('link', $attributes) . "\n";
1536             // This id is needed in first sheet only so that theme may override YUI sheets loaded on the fly.
1537             unset($attributes['id']);
1538         }
1539
1540         return $code;
1541     }
1542
1543     /**
1544      * Adds extra modules specified after printing of page header.
1545      *
1546      * @return string
1547      */
1548     protected function get_extra_modules_code() {
1549         if (empty($this->extramodules)) {
1550             return '';
1551         }
1552         return html_writer::script(js_writer::function_call('M.yui.add_module', array($this->extramodules)));
1553     }
1554
1555     /**
1556      * Generate any HTML that needs to go inside the <head> tag.
1557      *
1558      * Normally, this method is called automatically by the code that prints the
1559      * <head> tag. You should not normally need to call it in your own code.
1560      *
1561      * @param moodle_page $page
1562      * @param core_renderer $renderer
1563      * @return string the HTML code to to inside the <head> tag.
1564      */
1565     public function get_head_code(moodle_page $page, core_renderer $renderer) {
1566         global $CFG;
1567
1568         // Note: the $page and $output are not stored here because it would
1569         // create circular references in memory which prevents garbage collection.
1570         $this->init_requirements_data($page, $renderer);
1571
1572         $output = '';
1573
1574         // Add all standard CSS for this page.
1575         $output .= $this->get_css_code();
1576
1577         // Set up the M namespace.
1578         $js = "var M = {}; M.yui = {};\n";
1579
1580         // Capture the time now ASAP during page load. This minimises the lag when
1581         // we try to relate times on the server to times in the browser.
1582         // An example of where this is used is the quiz countdown timer.
1583         $js .= "M.pageloadstarttime = new Date();\n";
1584
1585         // Add a subset of Moodle configuration to the M namespace.
1586         $js .= js_writer::set_variable('M.cfg', $this->M_cfg, false);
1587
1588         // Set up global YUI3 loader object - this should contain all code needed by plugins.
1589         // Note: in JavaScript just use "YUI().use('overlay', function(Y) { .... });",
1590         //       this needs to be done before including any other script.
1591         $js .= $this->YUI_config->get_config_functions();
1592         $js .= js_writer::set_variable('YUI_config', $this->YUI_config, false) . "\n";
1593         $js .= "M.yui.loader = {modules: {}};\n"; // Backwards compatibility only, not used any more.
1594         $js = $this->YUI_config->update_header_js($js);
1595
1596         $output .= html_writer::script($js);
1597
1598         // Add variables.
1599         if ($this->jsinitvariables['head']) {
1600             $js = '';
1601             foreach ($this->jsinitvariables['head'] as $data) {
1602                 list($var, $value) = $data;
1603                 $js .= js_writer::set_variable($var, $value, true);
1604             }
1605             $output .= html_writer::script($js);
1606         }
1607
1608         // Mark head sending done, it is not possible to anything there.
1609         $this->headdone = true;
1610
1611         return $output;
1612     }
1613
1614     /**
1615      * Generate any HTML that needs to go at the start of the <body> tag.
1616      *
1617      * Normally, this method is called automatically by the code that prints the
1618      * <head> tag. You should not normally need to call it in your own code.
1619      *
1620      * @param renderer_base $renderer
1621      * @return string the HTML code to go at the start of the <body> tag.
1622      */
1623     public function get_top_of_body_code(renderer_base $renderer) {
1624         global $CFG;
1625
1626         // First the skip links.
1627         $output = $renderer->render_skip_links($this->skiplinks);
1628
1629         // Include the Polyfills.
1630         $output .= html_writer::script('', $this->js_fix_url('/lib/polyfills/polyfill.js'));
1631
1632         // YUI3 JS needs to be loaded early in the body. It should be cached well by the browser.
1633         $output .= $this->get_yui3lib_headcode();
1634
1635         // Add hacked jQuery support, it is not intended for standard Moodle distribution!
1636         $output .= $this->get_jquery_headcode();
1637
1638         // Link our main JS file, all core stuff should be there.
1639         $output .= html_writer::script('', $this->js_fix_url('/lib/javascript-static.js'));
1640
1641         // All the other linked things from HEAD - there should be as few as possible.
1642         if ($this->jsincludes['head']) {
1643             foreach ($this->jsincludes['head'] as $url) {
1644                 $output .= html_writer::script('', $url);
1645             }
1646         }
1647
1648         // Then the clever trick for hiding of things not needed when JS works.
1649         $output .= html_writer::script("document.body.className += ' jsenabled';") . "\n";
1650         $this->topofbodydone = true;
1651         return $output;
1652     }
1653
1654     /**
1655      * Generate any HTML that needs to go at the end of the page.
1656      *
1657      * Normally, this method is called automatically by the code that prints the
1658      * page footer. You should not normally need to call it in your own code.
1659      *
1660      * @return string the HTML code to to at the end of the page.
1661      */
1662     public function get_end_code() {
1663         global $CFG;
1664         $output = '';
1665
1666         // Set the log level for the JS logging.
1667         $logconfig = new stdClass();
1668         $logconfig->level = 'warn';
1669         if ($CFG->debugdeveloper) {
1670             $logconfig->level = 'trace';
1671         }
1672         $this->js_call_amd('core/log', 'setConfig', array($logconfig));
1673         // Add any global JS that needs to run on all pages.
1674         $this->js_call_amd('core/page_global', 'init');
1675         $this->js_call_amd('core/utility');
1676
1677         // Call amd init functions.
1678         $output .= $this->get_amd_footercode();
1679
1680         // Add other requested modules.
1681         $output .= $this->get_extra_modules_code();
1682
1683         $this->js_init_code('M.util.js_complete("init");', true);
1684
1685         // All the other linked scripts - there should be as few as possible.
1686         if ($this->jsincludes['footer']) {
1687             foreach ($this->jsincludes['footer'] as $url) {
1688                 $output .= html_writer::script('', $url);
1689             }
1690         }
1691
1692         // Add all needed strings.
1693         // First add core strings required for some dialogues.
1694         $this->strings_for_js(array(
1695             'confirm',
1696             'yes',
1697             'no',
1698             'areyousure',
1699             'closebuttontitle',
1700             'unknownerror',
1701             'error',
1702             'file',
1703             'url',
1704             // TODO MDL-70830 shortforms should preload the collapseall/expandall strings properly.
1705             'collapseall',
1706             'expandall',
1707         ), 'moodle');
1708         $this->strings_for_js(array(
1709             'debuginfo',
1710             'line',
1711             'stacktrace',
1712         ), 'debug');
1713         $this->string_for_js('labelsep', 'langconfig');
1714         if (!empty($this->stringsforjs)) {
1715             $strings = array();
1716             foreach ($this->stringsforjs as $component=>$v) {
1717                 foreach($v as $indentifier => $langstring) {
1718                     $strings[$component][$indentifier] = $langstring->out();
1719                 }
1720             }
1721             $output .= html_writer::script(js_writer::set_variable('M.str', $strings));
1722         }
1723
1724         // Add variables.
1725         if ($this->jsinitvariables['footer']) {
1726             $js = '';
1727             foreach ($this->jsinitvariables['footer'] as $data) {
1728                 list($var, $value) = $data;
1729                 $js .= js_writer::set_variable($var, $value, true);
1730             }
1731             $output .= html_writer::script($js);
1732         }
1733
1734         $inyuijs = $this->get_javascript_code(false);
1735         $ondomreadyjs = $this->get_javascript_code(true);
1736         $jsinit = $this->get_javascript_init_code();
1737         $handlersjs = $this->get_event_handler_code();
1738
1739         // There is a global Y, make sure it is available in your scope.
1740         $js = "(function() {{$inyuijs}{$ondomreadyjs}{$jsinit}{$handlersjs}})();";
1741
1742         $output .= html_writer::script($js);
1743
1744         return $output;
1745     }
1746
1747     /**
1748      * Have we already output the code in the <head> tag?
1749      *
1750      * @return bool
1751      */
1752     public function is_head_done() {
1753         return $this->headdone;
1754     }
1755
1756     /**
1757      * Have we already output the code at the start of the <body> tag?
1758      *
1759      * @return bool
1760      */
1761     public function is_top_of_body_done() {
1762         return $this->topofbodydone;
1763     }
1764
1765     /**
1766      * Should we generate a bit of content HTML that is only required once  on
1767      * this page (e.g. the contents of the modchooser), now? Basically, we call
1768      * {@link has_one_time_item_been_created()}, and if the thing has not already
1769      * been output, we return true to tell the caller to generate it, and also
1770      * call {@link set_one_time_item_created()} to record the fact that it is
1771      * about to be generated.
1772      *
1773      * That is, a typical usage pattern (in a renderer method) is:
1774      * <pre>
1775      * if (!$this->page->requires->should_create_one_time_item_now($thing)) {
1776      *     return '';
1777      * }
1778      * // Else generate it.
1779      * </pre>
1780      *
1781      * @param string $thing identifier for the bit of content. Should be of the form
1782      *      frankenstyle_things, e.g. core_course_modchooser.
1783      * @return bool if true, the caller should generate that bit of output now, otherwise don't.
1784      */
1785     public function should_create_one_time_item_now($thing) {
1786         if ($this->has_one_time_item_been_created($thing)) {
1787             return false;
1788         }
1789
1790         $this->set_one_time_item_created($thing);
1791         return true;
1792     }
1793
1794     /**
1795      * Has a particular bit of HTML that is only required once  on this page
1796      * (e.g. the contents of the modchooser) already been generated?
1797      *
1798      * Normally, you can use the {@link should_create_one_time_item_now()} helper
1799      * method rather than calling this method directly.
1800      *
1801      * @param string $thing identifier for the bit of content. Should be of the form
1802      *      frankenstyle_things, e.g. core_course_modchooser.
1803      * @return bool whether that bit of output has been created.
1804      */
1805     public function has_one_time_item_been_created($thing) {
1806         return isset($this->onetimeitemsoutput[$thing]);
1807     }
1808
1809     /**
1810      * Indicate that a particular bit of HTML that is only required once on this
1811      * page (e.g. the contents of the modchooser) has been generated (or is about to be)?
1812      *
1813      * Normally, you can use the {@link should_create_one_time_item_now()} helper
1814      * method rather than calling this method directly.
1815      *
1816      * @param string $thing identifier for the bit of content. Should be of the form
1817      *      frankenstyle_things, e.g. core_course_modchooser.
1818      */
1819     public function set_one_time_item_created($thing) {
1820         if ($this->has_one_time_item_been_created($thing)) {
1821             throw new coding_exception($thing . ' is only supposed to be ouput ' .
1822                     'once per page, but it seems to be being output again.');
1823         }
1824         return $this->onetimeitemsoutput[$thing] = true;
1825     }
1826 }
1827
1828 /**
1829  * This class represents the YUI configuration.
1830  *
1831  * @copyright 2013 Andrew Nicols
1832  * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
1833  * @since Moodle 2.5
1834  * @package core
1835  * @category output
1836  */
1837 class YUI_config {
1838     /**
1839      * These settings must be public so that when the object is converted to json they are exposed.
1840      * Note: Some of these are camelCase because YUI uses camelCase variable names.
1841      *
1842      * The settings are described and documented in the YUI API at:
1843      * - http://yuilibrary.com/yui/docs/api/classes/config.html
1844      * - http://yuilibrary.com/yui/docs/api/classes/Loader.html
1845      */
1846     public $debug = false;
1847     public $base;
1848     public $comboBase;
1849     public $combine;
1850     public $filter = null;
1851     public $insertBefore = 'firstthemesheet';
1852     public $groups = array();
1853     public $modules = array();
1854     /** @var array The log sources that should be not be logged. */
1855     public $logInclude = [];
1856     /** @var array Tog sources that should be logged. */
1857     public $logExclude = [];
1858     /** @var string The minimum log level for YUI logging statements. */
1859     public $logLevel;
1860
1861     /**
1862      * @var array List of functions used by the YUI Loader group pattern recognition.
1863      */
1864     protected $jsconfigfunctions = array();
1865
1866     /**
1867      * Create a new group within the YUI_config system.
1868      *
1869      * @param String $name The name of the group. This must be unique and
1870      * not previously used.
1871      * @param Array $config The configuration for this group.
1872      * @return void
1873      */
1874     public function add_group($name, $config) {
1875         if (isset($this->groups[$name])) {
1876             throw new coding_exception("A YUI configuration group for '{$name}' already exists. To make changes to this group use YUI_config->update_group().");
1877         }
1878         $this->groups[$name] = $config;
1879     }
1880
1881     /**
1882      * Update an existing group configuration
1883      *
1884      * Note, any existing configuration for that group will be wiped out.
1885      * This includes module configuration.
1886      *
1887      * @param String $name The name of the group. This must be unique and
1888      * not previously used.
1889      * @param Array $config The configuration for this group.
1890      * @return void
1891      */
1892     public function update_group($name, $config) {
1893         if (!isset($this->groups[$name])) {
1894             throw new coding_exception('The Moodle YUI module does not exist. You must define the moodle module config using YUI_config->add_module_config first.');
1895         }
1896         $this->groups[$name] = $config;
1897     }
1898
1899     /**
1900      * Set the value of a configuration function used by the YUI Loader's pattern testing.
1901      *
1902      * Only the body of the function should be passed, and not the whole function wrapper.
1903      *
1904      * The JS function your write will be passed a single argument 'name' containing the
1905      * name of the module being loaded.
1906      *
1907      * @param $function String the body of the JavaScript function. This should be used i
1908      * @return String the name of the function to use in the group pattern configuration.
1909      */
1910     public function set_config_function($function) {
1911         $configname = 'yui' . (count($this->jsconfigfunctions) + 1) . 'ConfigFn';
1912         if (isset($this->jsconfigfunctions[$configname])) {
1913             throw new coding_exception("A YUI config function with this name already exists. Config function names must be unique.");
1914         }
1915         $this->jsconfigfunctions[$configname] = $function;
1916         return '@' . $configname . '@';
1917     }
1918
1919     /**
1920      * Allow setting of the config function described in {@see set_config_function} from a file.
1921      * The contents of this file are then passed to set_config_function.
1922      *
1923      * When jsrev is positive, the function is minified and stored in a MUC cache for subsequent uses.
1924      *
1925      * @param $file The path to the JavaScript function used for YUI configuration.
1926      * @return String the name of the function to use in the group pattern configuration.
1927      */
1928     public function set_config_source($file) {
1929         global $CFG;
1930         $cache = cache::make('core', 'yuimodules');
1931
1932         // Attempt to get the metadata from the cache.
1933         $keyname = 'configfn_' . $file;
1934         $fullpath = $CFG->dirroot . '/' . $file;
1935         if (!isset($CFG->jsrev) || $CFG->jsrev == -1) {
1936             $cache->delete($keyname);
1937             $configfn = file_get_contents($fullpath);
1938         } else {
1939             $configfn = $cache->get($keyname);
1940             if ($configfn === false) {
1941                 require_once($CFG->libdir . '/jslib.php');
1942                 $configfn = core_minify::js_files(array($fullpath));
1943                 $cache->set($keyname, $configfn);
1944             }
1945         }
1946         return $this->set_config_function($configfn);
1947     }
1948
1949     /**
1950      * Retrieve the list of JavaScript functions for YUI_config groups.
1951      *
1952      * @return String The complete set of config functions
1953      */
1954     public function get_config_functions() {
1955         $configfunctions = '';
1956         foreach ($this->jsconfigfunctions as $functionname => $function) {
1957             $configfunctions .= "var {$functionname} = function(me) {";
1958             $configfunctions .= $function;
1959             $configfunctions .= "};\n";
1960         }
1961         return $configfunctions;
1962     }
1963
1964     /**
1965      * Update the header JavaScript with any required modification for the YUI Loader.
1966      *
1967      * @param $js String The JavaScript to manipulate.
1968      * @return String the modified JS string.
1969      */
1970     public function update_header_js($js) {
1971         // Update the names of the the configFn variables.
1972         // The PHP json_encode function cannot handle literal names so we have to wrap
1973         // them in @ and then replace them with literals of the same function name.
1974         foreach ($this->jsconfigfunctions as $functionname => $function) {
1975             $js = str_replace('"@' . $functionname . '@"', $functionname, $js);
1976         }
1977         return $js;
1978     }
1979
1980     /**
1981      * Add configuration for a specific module.
1982      *
1983      * @param String $name The name of the module to add configuration for.
1984      * @param Array $config The configuration for the specified module.
1985      * @param String $group The name of the group to add configuration for.
1986      * If not specified, then this module is added to the global
1987      * configuration.
1988      * @return void
1989      */
1990     public function add_module_config($name, $config, $group = null) {
1991         if ($group) {
1992             if (!isset($this->groups[$name])) {
1993                 throw new coding_exception('The Moodle YUI module does not exist. You must define the moodle module config using YUI_config->add_module_config first.');
1994             }
1995             if (!isset($this->groups[$group]['modules'])) {
1996                 $this->groups[$group]['modules'] = array();
1997             }
1998             $modules = &$this->groups[$group]['modules'];
1999         } else {
2000             $modules = &$this->modules;
2001         }
2002         $modules[$name] = $config;
2003     }
2004
2005     /**
2006      * Add the moodle YUI module metadata for the moodle group to the YUI_config instance.
2007      *
2008      * If js caching is disabled, metadata will not be served causing YUI to calculate
2009      * module dependencies as each module is loaded.
2010      *
2011      * If metadata does not exist it will be created and stored in a MUC entry.
2012      *
2013      * @return void
2014      */
2015     public function add_moodle_metadata() {
2016         global $CFG;
2017         if (!isset($this->groups['moodle'])) {
2018             throw new coding_exception('The Moodle YUI module does not exist. You must define the moodle module config using YUI_config->add_module_config first.');
2019         }
2020
2021         if (!isset($this->groups['moodle']['modules'])) {
2022             $this->groups['moodle']['modules'] = array();
2023         }
2024
2025         $cache = cache::make('core', 'yuimodules');
2026         if (!isset($CFG->jsrev) || $CFG->jsrev == -1) {
2027             $metadata = array();
2028             $metadata = $this->get_moodle_metadata();
2029             $cache->delete('metadata');
2030         } else {
2031             // Attempt to get the metadata from the cache.
2032             if (!$metadata = $cache->get('metadata')) {
2033                 $metadata = $this->get_moodle_metadata();
2034                 $cache->set('metadata', $metadata);
2035             }
2036         }
2037
2038         // Merge with any metadata added specific to this page which was added manually.
2039         $this->groups['moodle']['modules'] = array_merge($this->groups['moodle']['modules'],
2040                 $metadata);
2041     }
2042
2043     /**
2044      * Determine the module metadata for all moodle YUI modules.
2045      *
2046      * This works through all modules capable of serving YUI modules, and attempts to get
2047      * metadata for each of those modules.
2048      *
2049      * @return Array of module metadata
2050      */
2051     private function get_moodle_metadata() {
2052         $moodlemodules = array();
2053         // Core isn't a plugin type or subsystem - handle it seperately.
2054         if ($module = $this->get_moodle_path_metadata(core_component::get_component_directory('core'))) {
2055             $moodlemodules = array_merge($moodlemodules, $module);
2056         }
2057
2058         // Handle other core subsystems.
2059         $subsystems = core_component::get_core_subsystems();
2060         foreach ($subsystems as $subsystem => $path) {
2061             if (is_null($path)) {
2062                 continue;
2063             }
2064             if ($module = $this->get_moodle_path_metadata($path)) {
2065                 $moodlemodules = array_merge($moodlemodules, $module);
2066             }
2067         }
2068
2069         // And finally the plugins.
2070         $plugintypes = core_component::get_plugin_types();
2071         foreach ($plugintypes as $plugintype => $pathroot) {
2072             $pluginlist = core_component::get_plugin_list($plugintype);
2073             foreach ($pluginlist as $plugin => $path) {
2074                 if ($module = $this->get_moodle_path_metadata($path)) {
2075                     $moodlemodules = array_merge($moodlemodules, $module);
2076                 }
2077             }
2078         }
2079
2080         return $moodlemodules;
2081     }
2082
2083     /**
2084      * Helper function process and return the YUI metadata for all of the modules under the specified path.
2085      *
2086      * @param String $path the UNC path to the YUI src directory.
2087      * @return Array the complete array for frankenstyle directory.
2088      */
2089     private function get_moodle_path_metadata($path) {
2090         // Add module metadata is stored in frankenstyle_modname/yui/src/yui_modname/meta/yui_modname.json.
2091         $baseyui = $path . '/yui/src';
2092         $modules = array();
2093         if (is_dir($baseyui)) {
2094             $items = new DirectoryIterator($baseyui);
2095             foreach ($items as $item) {
2096                 if ($item->isDot() or !$item->isDir()) {
2097                     continue;
2098                 }
2099                 $metafile = realpath($baseyui . '/' . $item . '/meta/' . $item . '.json');
2100                 if (!is_readable($metafile)) {
2101                     continue;
2102                 }
2103                 $metadata = file_get_contents($metafile);
2104                 $modules = array_merge($modules, (array) json_decode($metadata));
2105             }
2106         }
2107         return $modules;
2108     }
2109
2110     /**
2111      * Define YUI modules which we have been required to patch between releases.
2112      *
2113      * We must do this because we aggressively cache content on the browser, and we must also override use of the
2114      * external CDN which will serve the true authoritative copy of the code without our patches.
2115      *
2116      * @param String combobase The local combobase
2117      * @param String yuiversion The current YUI version
2118      * @param Int patchlevel The patch level we're working to for YUI
2119      * @param Array patchedmodules An array containing the names of the patched modules
2120      * @return void
2121      */
2122     public function define_patched_core_modules($combobase, $yuiversion, $patchlevel, $patchedmodules) {
2123         // The version we use is suffixed with a patchlevel so that we can get additional revisions between YUI releases.
2124         $subversion = $yuiversion . '_' . $patchlevel;
2125
2126         if ($this->comboBase == $combobase) {
2127             // If we are using the local combobase in the loader, we can add a group and still make use of the combo
2128             // loader. We just need to specify a different root which includes a slightly different YUI version number
2129             // to include our patchlevel.
2130             $patterns = array();
2131             $modules = array();
2132             foreach ($patchedmodules as $modulename) {
2133                 // We must define the pattern and module here so that the loader uses our group configuration instead of
2134                 // the standard module definition. We may lose some metadata provided by upstream but this will be
2135                 // loaded when the module is loaded anyway.
2136                 $patterns[$modulename] = array(
2137                     'group' => 'yui-patched',
2138                 );
2139                 $modules[$modulename] = array();
2140             }
2141
2142             // Actually add the patch group here.
2143             $this->add_group('yui-patched', array(
2144                 'combine' => true,
2145                 'root' => $subversion . '/',
2146                 'patterns' => $patterns,
2147                 'modules' => $modules,
2148             ));
2149
2150         } else {
2151             // The CDN is in use - we need to instead use the local combobase for this module and override the modules
2152             // definition. We cannot use the local base - we must use the combobase because we cannot invalidate the
2153             // local base in browser caches.
2154             $fullpathbase = $combobase . $subversion . '/';
2155             foreach ($patchedmodules as $modulename) {
2156                 $this->modules[$modulename] = array(
2157                     'fullpath' => $fullpathbase . $modulename . '/' . $modulename . '-min.js'
2158                 );
2159             }
2160         }
2161     }
2162 }
2163
2164 /**
2165  * Invalidate all server and client side template caches.
2166  */
2167 function template_reset_all_caches() {
2168     global $CFG;
2169
2170     $next = time();
2171     if (isset($CFG->templaterev) and $next <= $CFG->templaterev and $CFG->templaterev - $next < 60 * 60) {
2172         // This resolves problems when reset is requested repeatedly within 1s,
2173         // the < 1h condition prevents accidental switching to future dates
2174         // because we might not recover from it.
2175         $next = $CFG->templaterev + 1;
2176     }
2177
2178     set_config('templaterev', $next);
2179 }
2180
2181 /**
2182  * Invalidate all server and client side JS caches.
2183  */
2184 function js_reset_all_caches() {
2185     global $CFG;
2186
2187     $next = time();
2188     if (isset($CFG->jsrev) and $next <= $CFG->jsrev and $CFG->jsrev - $next < 60*60) {
2189         // This resolves problems when reset is requested repeatedly within 1s,
2190         // the < 1h condition prevents accidental switching to future dates
2191         // because we might not recover from it.
2192         $next = $CFG->jsrev+1;
2193     }
2194
2195     set_config('jsrev', $next);
2196 }