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