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