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_init_call('M.mod_forum.init_view');
  39  * </pre>
  40  *
  41  * It also supports obsoleted coding style withouth YUI3 modules.
  42  * <pre>
  43  *     $PAGE->requires->css('/mod/mymod/userstyles.php?id='.$id); // not overridable via themes!
  44  *     $PAGE->requires->js('/mod/mymod/script.js');
  45  *     $PAGE->requires->js('/mod/mymod/small_but_urgent.js', true);
  46  *     $PAGE->requires->js_function_call('init_mymod', array($data), true);
  47  * </pre>
  48  *
  49  * There are some natural restrictions on some methods. For example, {@link css()}
  50  * can only be called before the <head> tag is output. See the comments on the
  51  * individual methods for details.
  52  *
  53  * @copyright 2009 Tim Hunt, 2010 Petr Skoda
  54  * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  55  * @since Moodle 2.0
  56  * @package core
  57  * @category output
  58  */
  59 class page_requirements_manager {
  60
  61     /**
  62      * @var array List of string available from JS
  63      */
  64     protected $stringsforjs = array();
  65
  66     /**
  67      * @var array List of get_string $a parameters - used for validation only.
  68      */
  69     protected $stringsforjs_as = array();
  70
  71     /**
  72      * @var array List of JS variables to be initialised
  73      */
  74     protected $jsinitvariables = array('head'=>array(), 'footer'=>array());
  75
  76     /**
  77      * @var array Included JS scripts
  78      */
  79     protected $jsincludes = array('head'=>array(), 'footer'=>array());
  80
  81     /**
  82      * @var array List of needed function calls
  83      */
  84     protected $jscalls = array('normal'=>array(), 'ondomready'=>array());
  85
  86     /**
  87      * @var array List of skip links, those are needed for accessibility reasons
  88      */
  89     protected $skiplinks = array();
  90
  91     /**
  92      * @var array Javascript code used for initialisation of page, it should
  93      * be relatively small
  94      */
  95     protected $jsinitcode = array();
  96
  97     /**
  98      * @var array of moodle_url Theme sheets, initialised only from core_renderer
  99      */
 100     protected $cssthemeurls = array();
 101
 102     /**
 103      * @var array of moodle_url List of custom theme sheets, these are strongly discouraged!
 104      * Useful mostly only for CSS submitted by teachers that is not part of the theme.
 105      */
 106     protected $cssurls = array();
 107
 108     /**
 109      * @var array List of requested event handlers
 110      */
 111     protected $eventhandlers = array();
 112
 113     /**
 114      * @var array Extra modules
 115      */
 116     protected $extramodules = array();
 117
 118     /**
 119      * @var array trackes the names of bits of HTML that are only required once
 120      * per page. See {@link has_one_time_item_been_created()},
 121      * {@link set_one_time_item_created()} and {@link should_create_one_time_item_now()}.
 122      */
 123     protected $onetimeitemsoutput = array();
 124
 125     /**
 126      * @var bool Flag indicated head stuff already printed
 127      */
 128     protected $headdone = false;
 129
 130     /**
 131      * @var bool Flag indicating top of body already printed
 132      */
 133     protected $topofbodydone = false;
 134
 135     /**
 136      * @var stdClass YUI PHPLoader instance responsible for YUI3 loading from PHP only
 137      */
 138     protected $yui3loader;
 139
 140     /**
 141      * @var YUI_config default YUI loader configuration
 142      */
 143     protected $YUI_config;
 144
 145     /**
 146      * @var array Some config vars exposed in JS, please no secret stuff there
 147      */
 148     protected $M_cfg;
 149
 150     /**
 151      * @var array list of requested jQuery plugins
 152      */
 153     protected $jqueryplugins = array();
 154
 155     /**
 156      * @var array list of jQuery plugin overrides
 157      */
 158     protected $jquerypluginoverrides = array();
 159
 160     /**
 161      * Page requirements constructor.
 162      */
 163     public function __construct() {
 164         global $CFG;
 165
 166         // You may need to set up URL rewrite rule because oversized URLs might not be allowed by web server.
 167         $sep = empty($CFG->yuislasharguments) ? '?' : '/';
 168
 169         $this->yui3loader = new stdClass();
 170         $this->YUI_config = new YUI_config();
 171
 172         if (strpos($CFG->httpswwwroot, 'https:') === 0) {
 173             // On HTTPS sites all JS must be loaded from https sites,
 174             // YUI CDN does not support https yet, sorry.
 175             $CFG->useexternalyui = 0;
 176         }
 177
 178         // Set up some loader options.
 179         $this->yui3loader->local_base = $CFG->httpswwwroot . '/lib/yuilib/'. $CFG->yui3version . '/';
 180         $this->yui3loader->local_comboBase = $CFG->httpswwwroot . '/theme/yui_combo.php'.$sep;
 181
 182         if (!empty($CFG->useexternalyui)) {
 183             $this->yui3loader->base = 'http://yui.yahooapis.com/' . $CFG->yui3version . '/';
 184             $this->yui3loader->comboBase = 'http://yui.yahooapis.com/combo?';
 185         } else {
 186             $this->yui3loader->base = $this->yui3loader->local_base;
 187             $this->yui3loader->comboBase = $this->yui3loader->local_comboBase;
 188         }
 189
 190         // Enable combo loader? This significantly helps with caching and performance!
 191         $this->yui3loader->combine = !empty($CFG->yuicomboloading);
 192
 193         $jsrev = $this->get_jsrev();
 194
 195         // Set up JS YUI loader helper object.
 196         $this->YUI_config->base         = $this->yui3loader->base;
 197         $this->YUI_config->comboBase    = $this->yui3loader->comboBase;
 198         $this->YUI_config->combine      = $this->yui3loader->combine;
 199
 200         // If we've had to patch any YUI modules between releases, we must override the YUI configuration to include them.
 201         // For important information on patching YUI modules, please see http://docs.moodle.org/dev/YUI/Patching.
 202         if (!empty($CFG->yuipatchedmodules) && !empty($CFG->yuipatchlevel)) {
 203             $this->YUI_config->define_patched_core_modules($this->yui3loader->local_comboBase,
 204                     $CFG->yui3version,
 205                     $CFG->yuipatchlevel,
 206                     $CFG->yuipatchedmodules);
 207         }
 208
 209         $configname = $this->YUI_config->set_config_source('lib/yui/config/yui2.js');
 210         $this->YUI_config->add_group('yui2', array(
 211             // Loader configuration for our 2in3, for now ignores $CFG->useexternalyui.
 212             'base' => $CFG->httpswwwroot . '/lib/yuilib/2in3/' . $CFG->yui2version . '/build/',
 213             'comboBase' => $CFG->httpswwwroot . '/theme/yui_combo.php'.$sep,
 214             'combine' => $this->yui3loader->combine,
 215             'ext' => false,
 216             'root' => '2in3/' . $CFG->yui2version .'/build/',
 217             'patterns' => array(
 218                 'yui2-' => array(
 219                     'group' => 'yui2',
 220                     'configFn' => $configname,
 221                 )
 222             )
 223         ));
 224         $configname = $this->YUI_config->set_config_source('lib/yui/config/moodle.js');
 225         $this->YUI_config->add_group('moodle', array(
 226             'name' => 'moodle',
 227             'base' => $CFG->httpswwwroot . '/theme/yui_combo.php' . $sep . 'm/' . $jsrev . '/',
 228             'combine' => $this->yui3loader->combine,
 229             'comboBase' => $CFG->httpswwwroot . '/theme/yui_combo.php'.$sep,
 230             'ext' => false,
 231             'root' => 'm/'.$jsrev.'/', // Add the rev to the root path so that we can control caching.
 232             'patterns' => array(
 233                 'moodle-' => array(
 234                     'group' => 'moodle',
 235                     'configFn' => $configname,
 236                 )
 237             )
 238         ));
 239
 240         $this->YUI_config->add_group('gallery', array(
 241             'name' => 'gallery',
 242             'base' => $CFG->httpswwwroot . '/lib/yuilib/gallery/',
 243             'combine' => $this->yui3loader->combine,
 244             'comboBase' => $CFG->httpswwwroot . '/theme/yui_combo.php' . $sep,
 245             'ext' => false,
 246             'root' => 'gallery/' . $jsrev . '/',
 247             'patterns' => array(
 248                 'gallery-' => array(
 249                     'group' => 'gallery',
 250                 )
 251             )
 252         ));
 253
 254         // Set some more loader options applying to groups too.
 255         if ($CFG->debugdeveloper) {
 256             // When debugging is enabled, we want to load the non-minified (RAW) versions of YUI library modules rather
 257             // than the DEBUG versions as these generally generate too much logging for our purposes.
 258             // However we do want the DEBUG versions of our Moodle-specific modules.
 259             // To debug a YUI-specific issue, change the yui3loader->filter value to DEBUG.
 260             $this->YUI_config->filter = 'RAW';
 261             $this->YUI_config->groups['moodle']['filter'] = 'DEBUG';
 262
 263             // We use the yui3loader->filter setting when writing the YUI3 seed scripts into the header.
 264             $this->yui3loader->filter = $this->YUI_config->filter;
 265             $this->YUI_config->debug = true;
 266         } else {
 267             $this->yui3loader->filter = null;
 268             $this->YUI_config->groups['moodle']['filter'] = null;
 269             $this->YUI_config->debug = false;
 270         }
 271
 272         // Include the YUI config log filters.
 273         if (!empty($CFG->yuilogexclude) && is_array($CFG->yuilogexclude)) {
 274             $this->YUI_config->logExclude = $CFG->yuilogexclude;
 275         }
 276         if (!empty($CFG->yuiloginclude) && is_array($CFG->yuiloginclude)) {
 277             $this->YUI_config->logInclude = $CFG->yuiloginclude;
 278         }
 279         if (!empty($CFG->yuiloglevel)) {
 280             $this->YUI_config->logLevel = $CFG->yuiloglevel;
 281         }
 282
 283         // Add the moodle group's module data.
 284         $this->YUI_config->add_moodle_metadata();
 285
 286         // Every page should include definition of following modules.
 287         $this->js_module($this->find_module('core_filepicker'));
 288     }
 289
 290     /**
 291      * Initialise with the bits of JavaScript that every Moodle page should have.
 292      *
 293      * @param moodle_page $page
 294      * @param core_renderer $renderer
 295      */
 296     protected function init_requirements_data(moodle_page $page, core_renderer $renderer) {
 297         global $CFG;
 298
 299         // JavaScript should always work with $CFG->httpswwwroot rather than $CFG->wwwroot.
 300         // Otherwise, in some situations, users will get warnings about insecure content
 301         // on secure pages from their web browser.
 302
 303         $this->M_cfg = array(
 304             'wwwroot'             => $CFG->httpswwwroot, // Yes, really. See above.
 305             'sesskey'             => sesskey(),
 306             'loadingicon'         => $renderer->pix_url('i/loading_small', 'moodle')->out(false),
 307             'themerev'            => theme_get_revision(),
 308             'slasharguments'      => (int)(!empty($CFG->slasharguments)),
 309             'theme'               => $page->theme->name,
 310             'jsrev'               => $this->get_jsrev(),
 311             'svgicons'            => $page->theme->use_svg_icons()
 312         );
 313         if ($CFG->debugdeveloper) {
 314             $this->M_cfg['developerdebug'] = true;
 315         }
 316         if (defined('BEHAT_SITE_RUNNING')) {
 317             $this->M_cfg['behatsiterunning'] = true;
 318         }
 319
 320         // Accessibility stuff.
 321         $this->skip_link_to('maincontent', get_string('tocontent', 'access'));
 322
 323         // Add strings used on many pages.
 324         $this->string_for_js('confirmation', 'admin');
 325         $this->string_for_js('cancel', 'moodle');
 326         $this->string_for_js('yes', 'moodle');
 327
 328         // Alter links in top frame to break out of frames.
 329         if ($page->pagelayout === 'frametop') {
 330             $this->js_init_call('M.util.init_frametop');
 331         }
 332
 333         // Include block drag/drop if editing is on
 334         if ($page->user_is_editing()) {
 335             $params = array(
 336                 'courseid' => $page->course->id,
 337                 'pagetype' => $page->pagetype,
 338                 'pagelayout' => $page->pagelayout,
 339                 'subpage' => $page->subpage,
 340                 'regions' => $page->blocks->get_regions(),
 341                 'contextid' => $page->context->id,
 342             );
 343             if (!empty($page->cm->id)) {
 344                 $params['cmid'] = $page->cm->id;
 345             }
 346             // Strings for drag and drop.
 347             $this->strings_for_js(array('movecontent',
 348                                         'tocontent',
 349                                         'emptydragdropregion'),
 350                                   'moodle');
 351             $page->requires->yui_module('moodle-core-blocks', 'M.core_blocks.init_dragdrop', array($params), null, true);
 352         }
 353     }
 354
 355     /**
 356      * Determine the correct JS Revision to use for this load.
 357      *
 358      * @return int the jsrev to use.
 359      */
 360     protected function get_jsrev() {
 361         global $CFG;
 362
 363         if (empty($CFG->cachejs)) {
 364             $jsrev = -1;
 365         } else if (empty($CFG->jsrev)) {
 366             $jsrev = 1;
 367         } else {
 368             $jsrev = $CFG->jsrev;
 369         }
 370
 371         return $jsrev;
 372     }
 373
 374     /**
 375      * Ensure that the specified JavaScript file is linked to from this page.
 376      *
 377      * NOTE: This function is to be used in RARE CASES ONLY, please store your JS in module.js file
 378      * and use $PAGE->requires->js_init_call() instead or use /yui/ subdirectories for YUI modules.
 379      *
 380      * By default the link is put at the end of the page, since this gives best page-load performance.
 381      *
 382      * Even if a particular script is requested more than once, it will only be linked
 383      * to once.
 384      *
 385      * @param string|moodle_url $url The path to the .js file, relative to $CFG->dirroot / $CFG->wwwroot.
 386      *      For example '/mod/mymod/customscripts.js'; use moodle_url for external scripts
 387      * @param bool $inhead initialise in head
 388      */
 389     public function js($url, $inhead = false) {
 390         $url = $this->js_fix_url($url);
 391         $where = $inhead ? 'head' : 'footer';
 392         $this->jsincludes[$where][$url->out()] = $url;
 393     }
 394
 395     /**
 396      * Request inclusion of jQuery library in the page.
 397      *
 398      * NOTE: this should not be used in official Moodle distribution!
 399      *
 400      * We are going to bundle jQuery 1.9.x until we drop support
 401      * all support for IE 6-8. Use $PAGE->requires->jquery_plugin('migrate')
 402      * for code written for earlier jQuery versions.
 403      *
 404      * {@see http://docs.moodle.org/dev/jQuery}
 405      */
 406     public function jquery() {
 407         $this->jquery_plugin('jquery');
 408     }
 409
 410     /**
 411      * Request inclusion of jQuery plugin.
 412      *
 413      * NOTE: this should not be used in official Moodle distribution!
 414      *
 415      * jQuery plugins are located in plugin/jquery/* subdirectory,
 416      * plugin/jquery/plugins.php lists all available plugins.
 417      *
 418      * Included core plugins:
 419      *   - jQuery UI
 420      *   - jQuery Migrate (useful for code written for previous UI version)
 421      *
 422      * Add-ons may include extra jQuery plugins in jquery/ directory,
 423      * plugins.php file defines the mapping between plugin names and
 424      * necessary page includes.
 425      *
 426      * Examples:
 427      * <code>
 428      *   // file: mod/xxx/view.php
 429      *   $PAGE->requires->jquery();
 430      *   $PAGE->requires->jquery_plugin('ui');
 431      *   $PAGE->requires->jquery_plugin('ui-css');
 432      * </code>
 433      *
 434      * <code>
 435      *   // file: theme/yyy/lib.php
 436      *   function theme_yyy_page_init(moodle_page $page) {
 437      *       $page->requires->jquery();
 438      *       $page->requires->jquery_plugin('ui');
 439      *       $page->requires->jquery_plugin('ui-css');
 440      *   }
 441      * </code>
 442      *
 443      * <code>
 444      *   // file: blocks/zzz/block_zzz.php
 445      *   public function get_required_javascript() {
 446      *       parent::get_required_javascript();
 447      *       $this->page->requires->jquery();
 448      *       $page->requires->jquery_plugin('ui');
 449      *       $page->requires->jquery_plugin('ui-css');
 450      *   }
 451      * </code>
 452      *
 453      * {@see http://docs.moodle.org/dev/jQuery}
 454      *
 455      * @param string $plugin name of the jQuery plugin as defined in jquery/plugins.php
 456      * @param string $component name of the component
 457      * @return bool success
 458      */
 459     public function jquery_plugin($plugin, $component = 'core') {
 460         global $CFG;
 461
 462         if ($this->headdone) {
 463             debugging('Can not add jQuery plugins after starting page output!');
 464             return false;
 465         }
 466
 467         if ($component !== 'core' and in_array($plugin, array('jquery', 'ui', 'ui-css', 'migrate'))) {
 468             debugging("jQuery plugin '$plugin' is included in Moodle core, other components can not use the same name.", DEBUG_DEVELOPER);
 469             $component = 'core';
 470         } else if ($component !== 'core' and strpos($component, '_') === false) {
 471             // Let's normalise the legacy activity names, Frankenstyle rulez!
 472             $component = 'mod_' . $component;
 473         }
 474
 475         if (empty($this->jqueryplugins) and ($component !== 'core' or $plugin !== 'jquery')) {
 476             // Make sure the jQuery itself is always loaded first,
 477             // the order of all other plugins depends on order of $PAGE_>requires->.
 478             $this->jquery_plugin('jquery', 'core');
 479         }
 480
 481         if (isset($this->jqueryplugins[$plugin])) {
 482             // No problem, we already have something, first Moodle plugin to register the jQuery plugin wins.
 483             return true;
 484         }
 485
 486         $componentdir = core_component::get_component_directory($component);
 487         if (!file_exists($componentdir) or !file_exists("$componentdir/jquery/plugins.php")) {
 488             debugging("Can not load jQuery plugin '$plugin', missing plugins.php in component '$component'.", DEBUG_DEVELOPER);
 489             return false;
 490         }
 491
 492         $plugins = array();
 493         require("$componentdir/jquery/plugins.php");
 494
 495         if (!isset($plugins[$plugin])) {
 496             debugging("jQuery plugin '$plugin' can not be found in component '$component'.", DEBUG_DEVELOPER);
 497             return false;
 498         }
 499
 500         $this->jqueryplugins[$plugin] = new stdClass();
 501         $this->jqueryplugins[$plugin]->plugin    = $plugin;
 502         $this->jqueryplugins[$plugin]->component = $component;
 503         $this->jqueryplugins[$plugin]->urls      = array();
 504
 505         foreach ($plugins[$plugin]['files'] as $file) {
 506             if ($CFG->debugdeveloper) {
 507                 if (!file_exists("$componentdir/jquery/$file")) {
 508                     debugging("Invalid file '$file' specified in jQuery plugin '$plugin' in component '$component'");
 509                     continue;
 510                 }
 511                 $file = str_replace('.min.css', '.css', $file);
 512                 $file = str_replace('.min.js', '.js', $file);
 513             }
 514             if (!file_exists("$componentdir/jquery/$file")) {
 515                 debugging("Invalid file '$file' specified in jQuery plugin '$plugin' in component '$component'");
 516                 continue;
 517             }
 518             if (!empty($CFG->slasharguments)) {
 519                 $url = new moodle_url("$CFG->httpswwwroot/theme/jquery.php");
 520                 $url->set_slashargument("/$component/$file");
 521
 522             } else {
 523                 // This is not really good, we need slasharguments for relative links, this means no caching...
 524                 $path = realpath("$componentdir/jquery/$file");
 525                 if (strpos($path, $CFG->dirroot) === 0) {
 526                     $url = $CFG->httpswwwroot.preg_replace('/^'.preg_quote($CFG->dirroot, '/').'/', '', $path);
 527                     $url = new moodle_url($url);
 528                 } else {
 529                     // Bad luck, fix your server!
 530                     debugging("Moodle jQuery integration requires 'slasharguments' setting to be enabled.");
 531                     continue;
 532                 }
 533             }
 534             $this->jqueryplugins[$plugin]->urls[] = $url;
 535         }
 536
 537         return true;
 538     }
 539
 540     /**
 541      * Request replacement of one jQuery plugin by another.
 542      *
 543      * This is useful when themes want to replace the jQuery UI theme,
 544      * the problem is that theme can not prevent others from including the core ui-css plugin.
 545      *
 546      * Example:
 547      *  1/ generate new jQuery UI theme and place it into theme/yourtheme/jquery/
 548      *  2/ write theme/yourtheme/jquery/plugins.php
 549      *  3/ init jQuery from theme
 550      *
 551      * <code>
 552      *   // file theme/yourtheme/lib.php
 553      *   function theme_yourtheme_page_init($page) {
 554      *       $page->requires->jquery_plugin('yourtheme-ui-css', 'theme_yourtheme');
 555      *       $page->requires->jquery_override_plugin('ui-css', 'yourtheme-ui-css');
 556      *   }
 557      * </code>
 558      *
 559      * This code prevents loading of standard 'ui-css' which my be requested by other plugins,
 560      * the 'yourtheme-ui-css' gets loaded only if some other code requires jquery.
 561      *
 562      * {@see http://docs.moodle.org/dev/jQuery}
 563      *
 564      * @param string $oldplugin original plugin
 565      * @param string $newplugin the replacement
 566      */
 567     public function jquery_override_plugin($oldplugin, $newplugin) {
 568         if ($this->headdone) {
 569             debugging('Can not override jQuery plugins after starting page output!');
 570             return;
 571         }
 572         $this->jquerypluginoverrides[$oldplugin] = $newplugin;
 573     }
 574
 575     /**
 576      * Return jQuery related markup for page start.
 577      * @return string
 578      */
 579     protected function get_jquery_headcode() {
 580         if (empty($this->jqueryplugins['jquery'])) {
 581             // If nobody requested jQuery then do not bother to load anything.
 582             // This may be useful for themes that want to override 'ui-css' only if requested by something else.
 583             return '';
 584         }
 585
 586         $included = array();
 587         $urls = array();
 588
 589         foreach ($this->jqueryplugins as $name => $unused) {
 590             if (isset($included[$name])) {
 591                 continue;
 592             }
 593             if (array_key_exists($name, $this->jquerypluginoverrides)) {
 594                 // The following loop tries to resolve the replacements,
 595                 // use max 100 iterations to prevent infinite loop resulting
 596                 // in blank page.
 597                 $cyclic = true;
 598                 $oldname = $name;
 599                 for ($i=0; $i<100; $i++) {
 600                     $name = $this->jquerypluginoverrides[$name];
 601                     if (!array_key_exists($name, $this->jquerypluginoverrides)) {
 602                         $cyclic = false;
 603                         break;
 604                     }
 605                 }
 606                 if ($cyclic) {
 607                     // We can not do much with cyclic references here, let's use the old plugin.
 608                     $name = $oldname;
 609                     debugging("Cyclic overrides detected for jQuery plugin '$name'");
 610
 611                 } else if (empty($name)) {
 612                     // Developer requested removal of the plugin.
 613                     continue;
 614
 615                 } else if (!isset($this->jqueryplugins[$name])) {
 616                     debugging("Unknown jQuery override plugin '$name' detected");
 617                     $name = $oldname;
 618
 619                 } else if (isset($included[$name])) {
 620                     // The plugin was already included, easy.
 621                     continue;
 622                 }
 623             }
 624
 625             $plugin = $this->jqueryplugins[$name];
 626             $urls = array_merge($urls, $plugin->urls);
 627             $included[$name] = true;
 628         }
 629
 630         $output = '';
 631         $attributes = array('rel' => 'stylesheet', 'type' => 'text/css');
 632         foreach ($urls as $url) {
 633             if (preg_match('/\.js$/', $url)) {
 634                 $output .= html_writer::script('', $url);
 635             } else if (preg_match('/\.css$/', $url)) {
 636                 $attributes['href'] = $url;
 637                 $output .= html_writer::empty_tag('link', $attributes) . "\n";
 638             }
 639         }
 640
 641         return $output;
 642     }
 643
 644     /**
 645      * Returns the actual url through which a script is served.
 646      *
 647      * @param moodle_url|string $url full moodle url, or shortened path to script
 648      * @return moodle_url
 649      */
 650     protected function js_fix_url($url) {
 651         global $CFG;
 652
 653         if ($url instanceof moodle_url) {
 654             return $url;
 655         } else if (strpos($url, '/') === 0) {
 656             // Fix the admin links if needed.
 657             if ($CFG->admin !== 'admin') {
 658                 if (strpos($url, "/admin/") === 0) {
 659                     $url = preg_replace("|^/admin/|", "/$CFG->admin/", $url);
 660                 }
 661             }
 662             if (debugging()) {
 663                 // Check file existence only when in debug mode.
 664                 if (!file_exists($CFG->dirroot . strtok($url, '?'))) {
 665                     throw new coding_exception('Attempt to require a JavaScript file that does not exist.', $url);
 666                 }
 667             }
 668             if (substr($url, -3) === '.js') {
 669                 $jsrev = $this->get_jsrev();
 670                 if (empty($CFG->slasharguments)) {
 671                     return new moodle_url($CFG->httpswwwroot.'/lib/javascript.php', array('rev'=>$jsrev, 'jsfile'=>$url));
 672                 } else {
 673                     $returnurl = new moodle_url($CFG->httpswwwroot.'/lib/javascript.php');
 674                     $returnurl->set_slashargument('/'.$jsrev.$url);
 675                     return $returnurl;
 676                 }
 677             } else {
 678                 return new moodle_url($CFG->httpswwwroot.$url);
 679             }
 680         } else {
 681             throw new coding_exception('Invalid JS url, it has to be shortened url starting with / or moodle_url instance.', $url);
 682         }
 683     }
 684
 685     /**
 686      * Find out if JS module present and return details.
 687      *
 688      * @param string $component name of component in frankenstyle, ex: core_group, mod_forum
 689      * @return array description of module or null if not found
 690      */
 691     protected function find_module($component) {
 692         global $CFG, $PAGE;
 693
 694         $module = null;
 695
 696         if (strpos($component, 'core_') === 0) {
 697             // Must be some core stuff - list here is not complete, this is just the stuff used from multiple places
 698             // so that we do nto have to repeat the definition of these modules over and over again.
 699             switch($component) {
 700                 case 'core_filepicker':
 701                     $module = array('name'     => 'core_filepicker',
 702                                     'fullpath' => '/repository/filepicker.js',
 703                                     'requires' => array('base', 'node', 'node-event-simulate', 'json', 'async-queue', 'io-base', 'io-upload-iframe', 'io-form', 'yui2-treeview', 'panel', 'cookie', 'datatable', 'datatable-sort', 'resize-plugin', 'dd-plugin', 'escape', 'moodle-core_filepicker'),
 704                                     'strings'  => array(array('lastmodified', 'moodle'), array('name', 'moodle'), array('type', 'repository'), array('size', 'repository'),
 705                                                         array('invalidjson', 'repository'), array('error', 'moodle'), array('info', 'moodle'),
 706                                                         array('nofilesattached', 'repository'), array('filepicker', 'repository'), array('logout', 'repository'),
 707                                                         array('nofilesavailable', 'repository'), array('norepositoriesavailable', 'repository'),
 708                                                         array('fileexistsdialogheader', 'repository'), array('fileexistsdialog_editor', 'repository'),
 709                                                         array('fileexistsdialog_filemanager', 'repository'), array('renameto', 'repository'),
 710                                                         array('referencesexist', 'repository'), array('select', 'repository')
 711                                                     ));
 712                     break;
 713                 case 'core_comment':
 714                     $module = array('name'     => 'core_comment',
 715                                     'fullpath' => '/comment/comment.js',
 716                                     'requires' => array('base', 'io-base', 'node', 'json', 'yui2-animation', 'overlay'),
 717                                     'strings' => array(array('confirmdeletecomments', 'admin'), array('yes', 'moodle'), array('no', 'moodle'))
 718                                 );
 719                     break;
 720                 case 'core_role':
 721                     $module = array('name'     => 'core_role',
 722                                     'fullpath' => '/admin/roles/module.js',
 723                                     'requires' => array('node', 'cookie'));
 724                     break;
 725                 case 'core_completion':
 726                     $module = array('name'     => 'core_completion',
 727                                     'fullpath' => '/course/completion.js');
 728                     break;
 729                 case 'core_message':
 730                     $module = array('name'     => 'core_message',
 731                                     'requires' => array('base', 'node', 'event', 'node-event-simulate'),
 732                                     'fullpath' => '/message/module.js');
 733                     break;
 734                 case 'core_group':
 735                     $module = array('name'     => 'core_group',
 736                                     'fullpath' => '/group/module.js',
 737                                     'requires' => array('node', 'overlay', 'event-mouseenter'));
 738                     break;
 739                 case 'core_question_engine':
 740                     $module = array('name'     => 'core_question_engine',
 741                                     'fullpath' => '/question/qengine.js',
 742                                     'requires' => array('node', 'event'));
 743                     break;
 744                 case 'core_rating':
 745                     $module = array('name'     => 'core_rating',
 746                                     'fullpath' => '/rating/module.js',
 747                                     'requires' => array('node', 'event', 'overlay', 'io-base', 'json'));
 748                     break;
 749                 case 'core_dndupload':
 750                     $module = array('name'     => 'core_dndupload',
 751                                     'fullpath' => '/lib/form/dndupload.js',
 752                                     'requires' => array('node', 'event', 'json', 'core_filepicker'),
 753                                     'strings'  => array(array('uploadformlimit', 'moodle'), array('droptoupload', 'moodle'), array('maxfilesreached', 'moodle'),
 754                                                         array('dndenabled_inbox', 'moodle'), array('fileexists', 'moodle'), array('maxbytesforfile', 'moodle'),
 755                                                         array('maxareabytesreached', 'moodle'), array('serverconnection', 'error'),
 756                                                     ));
 757                     break;
 758             }
 759
 760         } else {
 761             if ($dir = core_component::get_component_directory($component)) {
 762                 if (file_exists("$dir/module.js")) {
 763                     if (strpos($dir, $CFG->dirroot.'/') === 0) {
 764                         $dir = substr($dir, strlen($CFG->dirroot));
 765                         $module = array('name'=>$component, 'fullpath'=>"$dir/module.js", 'requires' => array());
 766                     }
 767                 }
 768             }
 769         }
 770
 771         return $module;
 772     }
 773
 774     /**
 775      * Append YUI3 module to default YUI3 JS loader.
 776      * The structure of module array is described at {@link http://developer.yahoo.com/yui/3/yui/}
 777      *
 778      * @param string|array $module name of module (details are autodetected), or full module specification as array
 779      * @return void
 780      */
 781     public function js_module($module) {
 782         global $CFG;
 783
 784         if (empty($module)) {
 785             throw new coding_exception('Missing YUI3 module name or full description.');
 786         }
 787
 788         if (is_string($module)) {
 789             $module = $this->find_module($module);
 790         }
 791
 792         if (empty($module) or empty($module['name']) or empty($module['fullpath'])) {
 793             throw new coding_exception('Missing YUI3 module details.');
 794         }
 795
 796         $module['fullpath'] = $this->js_fix_url($module['fullpath'])->out(false);
 797         // Add all needed strings.
 798         if (!empty($module['strings'])) {
 799             foreach ($module['strings'] as $string) {
 800                 $identifier = $string[0];
 801                 $component = isset($string[1]) ? $string[1] : 'moodle';
 802                 $a = isset($string[2]) ? $string[2] : null;
 803                 $this->string_for_js($identifier, $component, $a);
 804             }
 805         }
 806         unset($module['strings']);
 807
 808         // Process module requirements and attempt to load each. This allows
 809         // moodle modules to require each other.
 810         if (!empty($module['requires'])){
 811             foreach ($module['requires'] as $requirement) {
 812                 $rmodule = $this->find_module($requirement);
 813                 if (is_array($rmodule)) {
 814                     $this->js_module($rmodule);
 815                 }
 816             }
 817         }
 818
 819         if ($this->headdone) {
 820             $this->extramodules[$module['name']] = $module;
 821         } else {
 822             $this->YUI_config->add_module_config($module['name'], $module);
 823         }
 824     }
 825
 826     /**
 827      * Returns true if the module has already been loaded.
 828      *
 829      * @param string|array $module
 830      * @return bool True if the module has already been loaded
 831      */
 832     protected function js_module_loaded($module) {
 833         if (is_string($module)) {
 834             $modulename = $module;
 835         } else {
 836             $modulename = $module['name'];
 837         }
 838         return array_key_exists($modulename, $this->YUI_config->modules) ||
 839                array_key_exists($modulename, $this->extramodules);
 840     }
 841
 842     /**
 843      * Ensure that the specified CSS file is linked to from this page.
 844      *
 845      * Because stylesheet links must go in the <head> part of the HTML, you must call
 846      * this function before {@link get_head_code()} is called. That normally means before
 847      * the call to print_header. If you call it when it is too late, an exception
 848      * will be thrown.
 849      *
 850      * Even if a particular style sheet is requested more than once, it will only
 851      * be linked to once.
 852      *
 853      * Please note use of this feature is strongly discouraged,
 854      * it is suitable only for places where CSS is submitted directly by teachers.
 855      * (Students must not be allowed to submit any external CSS because it may
 856      * contain embedded javascript!). Example of correct use is mod/data.
 857      *
 858      * @param string $stylesheet The path to the .css file, relative to $CFG->wwwroot.
 859      *   For example:
 860      *      $PAGE->requires->css('mod/data/css.php?d='.$data->id);
 861      */
 862     public function css($stylesheet) {
 863         global $CFG;
 864
 865         if ($this->headdone) {
 866             throw new coding_exception('Cannot require a CSS file after &lt;head> has been printed.', $stylesheet);
 867         }
 868
 869         if ($stylesheet instanceof moodle_url) {
 870             // ok
 871         } else if (strpos($stylesheet, '/') === 0) {
 872             $stylesheet = new moodle_url($CFG->httpswwwroot.$stylesheet);
 873         } else {
 874             throw new coding_exception('Invalid stylesheet parameter.', $stylesheet);
 875         }
 876
 877         $this->cssurls[$stylesheet->out()] = $stylesheet;
 878     }
 879
 880     /**
 881      * Add theme stylesheet to page - do not use from plugin code,
 882      * this should be called only from the core renderer!
 883      *
 884      * @param moodle_url $stylesheet
 885      * @return void
 886      */
 887     public function css_theme(moodle_url $stylesheet) {
 888         $this->cssthemeurls[] = $stylesheet;
 889     }
 890
 891     /**
 892      * Ensure that a skip link to a given target is printed at the top of the <body>.
 893      *
 894      * You must call this function before {@link get_top_of_body_code()}, (if not, an exception
 895      * will be thrown). That normally means you must call this before the call to print_header.
 896      *
 897      * If you ask for a particular skip link to be printed, it is then your responsibility
 898      * to ensure that the appropriate <a name="..."> tag is printed in the body of the
 899      * page, so that the skip link goes somewhere.
 900      *
 901      * Even if a particular skip link is requested more than once, only one copy of it will be output.
 902      *
 903      * @param string $target the name of anchor this link should go to. For example 'maincontent'.
 904      * @param string $linktext The text to use for the skip link. Normally get_string('skipto', 'access', ...);
 905      */
 906     public function skip_link_to($target, $linktext) {
 907         if ($this->topofbodydone) {
 908             debugging('Page header already printed, can not add skip links any more, code needs to be fixed.');
 909             return;
 910         }
 911         $this->skiplinks[$target] = $linktext;
 912     }
 913
 914     /**
 915      * !!!DEPRECATED!!! please use js_init_call() if possible
 916      * Ensure that the specified JavaScript function is called from an inline script
 917      * somewhere on this page.
 918      *
 919      * By default the call will be put in a script tag at the
 920      * end of the page after initialising Y instance, since this gives best page-load
 921      * performance and allows you to use YUI3 library.
 922      *
 923      * If you request that a particular function is called several times, then
 924      * that is what will happen (unlike linking to a CSS or JS file, where only
 925      * one link will be output).
 926      *
 927      * The main benefit of the method is the automatic encoding of all function parameters.
 928      *
 929      * @deprecated
 930      *
 931      * @param string $function the name of the JavaScritp function to call. Can
 932      *      be a compound name like 'Y.Event.purgeElement'. Can also be
 933      *      used to create and object by using a 'function name' like 'new user_selector'.
 934      * @param array $arguments and array of arguments to be passed to the function.
 935      *      When generating the function call, this will be escaped using json_encode,
 936      *      so passing objects and arrays should work.
 937      * @param bool $ondomready If tru the function is only called when the dom is
 938      *      ready for manipulation.
 939      * @param int $delay The delay before the function is called.
 940      */
 941     public function js_function_call($function, array $arguments = null, $ondomready = false, $delay = 0) {
 942         $where = $ondomready ? 'ondomready' : 'normal';
 943         $this->jscalls[$where][] = array($function, $arguments, $delay);
 944     }
 945
 946     /**
 947      * Creates a JavaScript function call that requires one or more modules to be loaded.
 948      *
 949      * This function can be used to include all of the standard YUI module types within JavaScript:
 950      *     - YUI3 modules    [node, event, io]
 951      *     - YUI2 modules    [yui2-*]
 952      *     - Moodle modules  [moodle-*]
 953      *     - Gallery modules [gallery-*]
 954      *
 955      * @param array|string $modules One or more modules
 956      * @param string $function The function to call once modules have been loaded
 957      * @param array $arguments An array of arguments to pass to the function
 958      * @param string $galleryversion Deprecated: The gallery version to use
 959      * @param bool $ondomready
 960      */
 961     public function yui_module($modules, $function, array $arguments = null, $galleryversion = null, $ondomready = false) {
 962         if (!is_array($modules)) {
 963             $modules = array($modules);
 964         }
 965
 966         if ($galleryversion != null) {
 967             debugging('The galleryversion parameter to yui_module has been deprecated since Moodle 2.3.');
 968         }
 969
 970         $jscode = 'Y.use('.join(',', array_map('json_encode', convert_to_array($modules))).',function() {'.js_writer::function_call($function, $arguments).'});';
 971         if ($ondomready) {
 972             $jscode = "Y.on('domready', function() { $jscode });";
 973         }
 974         $this->jsinitcode[] = $jscode;
 975     }
 976
 977     /**
 978      * Ensure that the specified JavaScript function is called from an inline script
 979      * from page footer.
 980      *
 981      * @param string $function the name of the JavaScritp function to with init code,
 982      *      usually something like 'M.mod_mymodule.init'
 983      * @param array $extraarguments and array of arguments to be passed to the function.
 984      *      The first argument is always the YUI3 Y instance with all required dependencies
 985      *      already loaded.
 986      * @param bool $ondomready wait for dom ready (helps with some IE problems when modifying DOM)
 987      * @param array $module JS module specification array
 988      */
 989     public function js_init_call($function, array $extraarguments = null, $ondomready = false, array $module = null) {
 990         $jscode = js_writer::function_call_with_Y($function, $extraarguments);
 991         if (!$module) {
 992             // Detect module automatically.
 993             if (preg_match('/M\.([a-z0-9]+_[^\.]+)/', $function, $matches)) {
 994                 $module = $this->find_module($matches[1]);
 995             }
 996         }
 997
 998         $this->js_init_code($jscode, $ondomready, $module);
 999     }
1000
1001     /**
1002      * Add short static javascript code fragment to page footer.
1003      * This is intended primarily for loading of js modules and initialising page layout.
1004      * Ideally the JS code fragment should be stored in plugin renderer so that themes
1005      * may override it.
1006      *
1007      * @param string $jscode
1008      * @param bool $ondomready wait for dom ready (helps with some IE problems when modifying DOM)
1009      * @param array $module JS module specification array
1010      */
1011     public function js_init_code($jscode, $ondomready = false, array $module = null) {
1012         $jscode = trim($jscode, " ;\n"). ';';
1013
1014         $uniqid = html_writer::random_id();
1015         $startjs = " M.util.js_pending('" . $uniqid . "');";
1016         $endjs = " M.util.js_complete('" . $uniqid . "');";
1017
1018         if ($module) {
1019             $this->js_module($module);
1020             $modulename = $module['name'];
1021             $jscode = "$startjs Y.use('$modulename', function(Y) { $jscode $endjs });";
1022         }
1023
1024         if ($ondomready) {
1025             $jscode = "$startjs Y.on('domready', function() { $jscode $endjs });";
1026         }
1027
1028         $this->jsinitcode[] = $jscode;
1029     }
1030
1031     /**
1032      * Make a language string available to JavaScript.
1033      *
1034      * All the strings will be available in a M.str object in the global namespace.
1035      * So, for example, after a call to $PAGE->requires->string_for_js('course', 'moodle');
1036      * then the JavaScript variable M.str.moodle.course will be 'Course', or the
1037      * equivalent in the current language.
1038      *
1039      * The arguments to this function are just like the arguments to get_string
1040      * except that $component is not optional, and there are some aspects to consider
1041      * when the string contains {$a} placeholder.
1042      *
1043      * If the string does not contain any {$a} placeholder, you can simply use
1044      * M.str.component.identifier to obtain it. If you prefer, you can call
1045      * M.util.get_string(identifier, component) to get the same result.
1046      *
1047      * If you need to use {$a} placeholders, there are two options. Either the
1048      * placeholder should be substituted in PHP on server side or it should
1049      * be substituted in Javascript at client side.
1050      *
1051      * To substitute the placeholder at server side, just provide the required
1052      * value for the placeholder when you require the string. Because each string
1053      * is only stored once in the JavaScript (based on $identifier and $module)
1054      * you cannot get the same string with two different values of $a. If you try,
1055      * an exception will be thrown. Once the placeholder is substituted, you can
1056      * use M.str or M.util.get_string() as shown above:
1057      *
1058      *     // Require the string in PHP and replace the placeholder.
1059      *     $PAGE->requires->string_for_js('fullnamedisplay', 'moodle', $USER);
1060      *     // Use the result of the substitution in Javascript.
1061      *     alert(M.str.moodle.fullnamedisplay);
1062      *
1063      * To substitute the placeholder at client side, use M.util.get_string()
1064      * function. It implements the same logic as {@link get_string()}:
1065      *
1066      *     // Require the string in PHP but keep {$a} as it is.
1067      *     $PAGE->requires->string_for_js('fullnamedisplay', 'moodle');
1068      *     // Provide the values on the fly in Javascript.
1069      *     user = { firstname : 'Harry', lastname : 'Potter' }
1070      *     alert(M.util.get_string('fullnamedisplay', 'moodle', user);
1071      *
1072      * If you do need the same string expanded with different $a values in PHP
1073      * on server side, then the solution is to put them in your own data structure
1074      * (e.g. and array) that you pass to JavaScript with {@link data_for_js()}.
1075      *
1076      * @param string $identifier the desired string.
1077      * @param string $component the language file to look in.
1078      * @param mixed $a any extra data to add into the string (optional).
1079      */
1080     public function string_for_js($identifier, $component, $a = null) {
1081         if (!$component) {
1082             throw new coding_exception('The $component parameter is required for page_requirements_manager::string_for_js().');
1083         }
1084         if (isset($this->stringsforjs_as[$component][$identifier]) and $this->stringsforjs_as[$component][$identifier] !== $a) {
1085             throw new coding_exception("Attempt to re-define already required string '$identifier' " .
1086                     "from lang file '$component' with different \$a parameter?");
1087         }
1088         if (!isset($this->stringsforjs[$component][$identifier])) {
1089             $this->stringsforjs[$component][$identifier] = new lang_string($identifier, $component, $a);
1090             $this->stringsforjs_as[$component][$identifier] = $a;
1091         }
1092     }
1093
1094     /**
1095      * Make an array of language strings available for JS.
1096      *
1097      * This function calls the above function {@link string_for_js()} for each requested
1098      * string in the $identifiers array that is passed to the argument for a single module
1099      * passed in $module.
1100      *
1101      * <code>
1102      * $PAGE->requires->strings_for_js(array('one', 'two', 'three'), 'mymod', array('a', null, 3));
1103      *
1104      * // The above is identical to calling:
1105      *
1106      * $PAGE->requires->string_for_js('one', 'mymod', 'a');
1107      * $PAGE->requires->string_for_js('two', 'mymod');
1108      * $PAGE->requires->string_for_js('three', 'mymod', 3);
1109      * </code>
1110      *
1111      * @param array $identifiers An array of desired strings
1112      * @param string $component The module to load for
1113      * @param mixed $a This can either be a single variable that gets passed as extra
1114      *         information for every string or it can be an array of mixed data where the
1115      *         key for the data matches that of the identifier it is meant for.
1116      *
1117      */
1118     public function strings_for_js($identifiers, $component, $a = null) {
1119         foreach ($identifiers as $key => $identifier) {
1120             if (is_array($a) && array_key_exists($key, $a)) {
1121                 $extra = $a[$key];
1122             } else {
1123                 $extra = $a;
1124             }
1125             $this->string_for_js($identifier, $component, $extra);
1126         }
1127     }
1128
1129     /**
1130      * !!!!!!DEPRECATED!!!!!! please use js_init_call() for everything now.
1131      *
1132      * Make some data from PHP available to JavaScript code.
1133      *
1134      * For example, if you call
1135      * <pre>
1136      *      $PAGE->requires->data_for_js('mydata', array('name' => 'Moodle'));
1137      * </pre>
1138      * then in JavsScript mydata.name will be 'Moodle'.
1139      *
1140      * @deprecated
1141      * @param string $variable the the name of the JavaScript variable to assign the data to.
1142      *      Will probably work if you use a compound name like 'mybuttons.button[1]', but this
1143      *      should be considered an experimental feature.
1144      * @param mixed $data The data to pass to JavaScript. This will be escaped using json_encode,
1145      *      so passing objects and arrays should work.
1146      * @param bool $inhead initialise in head
1147      * @return void
1148      */
1149     public function data_for_js($variable, $data, $inhead=false) {
1150         $where = $inhead ? 'head' : 'footer';
1151         $this->jsinitvariables[$where][] = array($variable, $data);
1152     }
1153
1154     /**
1155      * Creates a YUI event handler.
1156      *
1157      * @param mixed $selector standard YUI selector for elements, may be array or string, element id is in the form "#idvalue"
1158      * @param string $event A valid DOM event (click, mousedown, change etc.)
1159      * @param string $function The name of the function to call
1160      * @param array  $arguments An optional array of argument parameters to pass to the function
1161      */
1162     public function event_handler($selector, $event, $function, array $arguments = null) {
1163         $this->eventhandlers[] = array('selector'=>$selector, 'event'=>$event, 'function'=>$function, 'arguments'=>$arguments);
1164     }
1165
1166     /**
1167      * Returns code needed for registering of event handlers.
1168      * @return string JS code
1169      */
1170     protected function get_event_handler_code() {
1171         $output = '';
1172         foreach ($this->eventhandlers as $h) {
1173             $output .= js_writer::event_handler($h['selector'], $h['event'], $h['function'], $h['arguments']);
1174         }
1175         return $output;
1176     }
1177
1178     /**
1179      * Get the inline JavaScript code that need to appear in a particular place.
1180      * @param bool $ondomready
1181      * @return string
1182      */
1183     protected function get_javascript_code($ondomready) {
1184         $where = $ondomready ? 'ondomready' : 'normal';
1185         $output = '';
1186         if ($this->jscalls[$where]) {
1187             foreach ($this->jscalls[$where] as $data) {
1188                 $output .= js_writer::function_call($data[0], $data[1], $data[2]);
1189             }
1190             if (!empty($ondomready)) {
1191                 $output = "    Y.on('domready', function() {\n$output\n});";
1192             }
1193         }
1194         return $output;
1195     }
1196
1197     /**
1198      * Returns js code to be executed when Y is available.
1199      * @return string
1200      */
1201     protected function get_javascript_init_code() {
1202         if (count($this->jsinitcode)) {
1203             return implode("\n", $this->jsinitcode) . "\n";
1204         }
1205         return '';
1206     }
1207
1208     /**
1209      * Returns basic YUI3 JS loading code.
1210      * YUI3 is using autoloading of both CSS and JS code.
1211      *
1212      * Major benefit of this compared to standard js/csss loader is much improved
1213      * caching, better browser cache utilisation, much fewer http requests.
1214      *
1215      * @param moodle_page $page
1216      * @return string
1217      */
1218     protected function get_yui3lib_headcode($page) {
1219         global $CFG;
1220
1221         $code = '';
1222
1223         $jsrev = $this->get_jsrev();
1224
1225         $yuiformat = '-min';
1226         if ($this->yui3loader->filter === 'RAW') {
1227             $yuiformat = '';
1228         }
1229
1230         $format = '-min';
1231         if ($this->YUI_config->groups['moodle']['filter'] === 'DEBUG') {
1232             $format = '-debug';
1233         }
1234
1235         $rollupversion = $CFG->yui3version;
1236         if (!empty($CFG->yuipatchlevel)) {
1237             $rollupversion .= '_' . $CFG->yuipatchlevel;
1238         }
1239
1240         $baserollups = array(
1241             'rollup/' . $rollupversion . "/yui-moodlesimple{$yuiformat}.js",
1242             'rollup/' . $jsrev . "/mcore{$format}.js",
1243         );
1244
1245         if ($this->yui3loader->combine) {
1246             if (!empty($page->theme->yuicssmodules)) {
1247                 $modules = array();
1248                 foreach ($page->theme->yuicssmodules as $module) {
1249                     $modules[] = "$CFG->yui3version/$module/$module-min.css";
1250                 }
1251                 $code .= '<link rel="stylesheet" type="text/css" href="'.$this->yui3loader->comboBase.implode('&amp;', $modules).'" />';
1252             }
1253             $code .= '<link rel="stylesheet" type="text/css" href="'.$this->yui3loader->local_comboBase.'rollup/'.$CFG->yui3version.'/yui-moodlesimple' . $yuiformat . '.css" />';
1254             $code .= '<script type="text/javascript" src="'.$this->yui3loader->local_comboBase
1255                     . implode('&amp;', $baserollups) . '"></script>';
1256
1257         } else {
1258             if (!empty($page->theme->yuicssmodules)) {
1259                 foreach ($page->theme->yuicssmodules as $module) {
1260                     $code .= '<link rel="stylesheet" type="text/css" href="'.$this->yui3loader->base.$module.'/'.$module.'-min.css" />';
1261                 }
1262             }
1263             $code .= '<link rel="stylesheet" type="text/css" href="'.$this->yui3loader->local_comboBase.'rollup/'.$CFG->yui3version.'/yui-moodlesimple' . $yuiformat . '.css" />';
1264             foreach ($baserollups as $rollup) {
1265                 $code .= '<script type="text/javascript" src="'.$this->yui3loader->local_comboBase.$rollup.'"></script>';
1266             }
1267         }
1268
1269         if ($this->yui3loader->filter === 'RAW') {
1270             $code = str_replace('-min.css', '.css', $code);
1271         } else if ($this->yui3loader->filter === 'DEBUG') {
1272             $code = str_replace('-min.css', '.css', $code);
1273         }
1274         return $code;
1275     }
1276
1277     /**
1278      * Returns html tags needed for inclusion of theme CSS.
1279      *
1280      * @return string
1281      */
1282     protected function get_css_code() {
1283         // First of all the theme CSS, then any custom CSS
1284         // Please note custom CSS is strongly discouraged,
1285         // because it can not be overridden by themes!
1286         // It is suitable only for things like mod/data which accepts CSS from teachers.
1287         $attributes = array('rel'=>'stylesheet', 'type'=>'text/css');
1288
1289         // This line of code may look funny but it is currently required in order
1290         // to avoid MASSIVE display issues in Internet Explorer.
1291         // As of IE8 + YUI3.1.1 the reference stylesheet (firstthemesheet) gets
1292         // ignored whenever another resource is added until such time as a redraw
1293         // is forced, usually by moving the mouse over the affected element.
1294         $code = html_writer::tag('script', '/** Required in order to fix style inclusion problems in IE with YUI **/', array('id'=>'firstthemesheet', 'type'=>'text/css'));
1295
1296         $urls = $this->cssthemeurls + $this->cssurls;
1297         foreach ($urls as $url) {
1298             $attributes['href'] = $url;
1299             $code .= html_writer::empty_tag('link', $attributes) . "\n";
1300             // This id is needed in first sheet only so that theme may override YUI sheets loaded on the fly.
1301             unset($attributes['id']);
1302         }
1303
1304         return $code;
1305     }
1306
1307     /**
1308      * Adds extra modules specified after printing of page header.
1309      *
1310      * @return string
1311      */
1312     protected function get_extra_modules_code() {
1313         if (empty($this->extramodules)) {
1314             return '';
1315         }
1316         return html_writer::script(js_writer::function_call('M.yui.add_module', array($this->extramodules)));
1317     }
1318
1319     /**
1320      * Generate any HTML that needs to go inside the <head> tag.
1321      *
1322      * Normally, this method is called automatically by the code that prints the
1323      * <head> tag. You should not normally need to call it in your own code.
1324      *
1325      * @param moodle_page $page
1326      * @param core_renderer $renderer
1327      * @return string the HTML code to to inside the <head> tag.
1328      */
1329     public function get_head_code(moodle_page $page, core_renderer $renderer) {
1330         global $CFG;
1331
1332         // Note: the $page and $output are not stored here because it would
1333         // create circular references in memory which prevents garbage collection.
1334         $this->init_requirements_data($page, $renderer);
1335
1336         $output = '';
1337
1338         // Set up the M namespace.
1339         $js = "var M = {}; M.yui = {};\n";
1340
1341         // Capture the time now ASAP during page load. This minimises the lag when
1342         // we try to relate times on the server to times in the browser.
1343         // An example of where this is used is the quiz countdown timer.
1344         $js .= "M.pageloadstarttime = new Date();\n";
1345
1346         // Add a subset of Moodle configuration to the M namespace.
1347         $js .= js_writer::set_variable('M.cfg', $this->M_cfg, false);
1348
1349         // Set up global YUI3 loader object - this should contain all code needed by plugins.
1350         // Note: in JavaScript just use "YUI().use('overlay', function(Y) { .... });",
1351         //       this needs to be done before including any other script.
1352         $js .= $this->YUI_config->get_config_functions();
1353         $js .= js_writer::set_variable('YUI_config', $this->YUI_config, false) . "\n";
1354         $js .= "M.yui.loader = {modules: {}};\n"; // Backwards compatibility only, not used any more.
1355         $js = $this->YUI_config->update_header_js($js);
1356
1357         $output .= html_writer::script($js);
1358
1359         // YUI3 JS and CSS need to be loaded in the header but after the YUI_config has been created.
1360         // They should be cached well by the browser.
1361         $output .= $this->get_yui3lib_headcode($page);
1362
1363         // Add hacked jQuery support, it is not intended for standard Moodle distribution!
1364         $output .= $this->get_jquery_headcode();
1365
1366         // Now theme CSS + custom CSS in this specific order.
1367         $output .= $this->get_css_code();
1368
1369         // Link our main JS file, all core stuff should be there.
1370         $output .= html_writer::script('', $this->js_fix_url('/lib/javascript-static.js'));
1371
1372         // Add variables.
1373         if ($this->jsinitvariables['head']) {
1374             $js = '';
1375             foreach ($this->jsinitvariables['head'] as $data) {
1376                 list($var, $value) = $data;
1377                 $js .= js_writer::set_variable($var, $value, true);
1378             }
1379             $output .= html_writer::script($js);
1380         }
1381
1382         // All the other linked things from HEAD - there should be as few as possible.
1383         if ($this->jsincludes['head']) {
1384             foreach ($this->jsincludes['head'] as $url) {
1385                 $output .= html_writer::script('', $url);
1386             }
1387         }
1388
1389         // Mark head sending done, it is not possible to anything there.
1390         $this->headdone = true;
1391
1392         return $output;
1393     }
1394
1395     /**
1396      * Generate any HTML that needs to go at the start of the <body> tag.
1397      *
1398      * Normally, this method is called automatically by the code that prints the
1399      * <head> tag. You should not normally need to call it in your own code.
1400      *
1401      * @return string the HTML code to go at the start of the <body> tag.
1402      */
1403     public function get_top_of_body_code() {
1404         // First the skip links.
1405         $links = '';
1406         $attributes = array('class'=>'skip');
1407         foreach ($this->skiplinks as $url => $text) {
1408             $attributes['href'] = '#' . $url;
1409             $links .= html_writer::tag('a', $text, $attributes);
1410         }
1411         $output = html_writer::tag('div', $links, array('class'=>'skiplinks')) . "\n";
1412
1413         // Then the clever trick for hiding of things not needed when JS works.
1414         $output .= html_writer::script("document.body.className += ' jsenabled';") . "\n";
1415         $this->topofbodydone = true;
1416         return $output;
1417     }
1418
1419     /**
1420      * Generate any HTML that needs to go at the end of the page.
1421      *
1422      * Normally, this method is called automatically by the code that prints the
1423      * page footer. You should not normally need to call it in your own code.
1424      *
1425      * @return string the HTML code to to at the end of the page.
1426      */
1427     public function get_end_code() {
1428         global $CFG;
1429
1430         // Add other requested modules.
1431         $output = $this->get_extra_modules_code();
1432
1433         $this->js_init_code('M.util.js_complete("init");', true);
1434
1435         // All the other linked scripts - there should be as few as possible.
1436         if ($this->jsincludes['footer']) {
1437             foreach ($this->jsincludes['footer'] as $url) {
1438                 $output .= html_writer::script('', $url);
1439             }
1440         }
1441
1442         // Add all needed strings.
1443         // First add core strings required for some dialogues.
1444         $this->strings_for_js(array(
1445             'confirm',
1446             'yes',
1447             'no',
1448             'areyousure',
1449             'closebuttontitle',
1450             'unknownerror',
1451         ), 'moodle');
1452         if (!empty($this->stringsforjs)) {
1453             $strings = array();
1454             foreach ($this->stringsforjs as $component=>$v) {
1455                 foreach($v as $indentifier => $langstring) {
1456                     $strings[$component][$indentifier] = $langstring->out();
1457                 }
1458             }
1459             $output .= html_writer::script(js_writer::set_variable('M.str', $strings));
1460         }
1461
1462         // Add variables.
1463         if ($this->jsinitvariables['footer']) {
1464             $js = '';
1465             foreach ($this->jsinitvariables['footer'] as $data) {
1466                 list($var, $value) = $data;
1467                 $js .= js_writer::set_variable($var, $value, true);
1468             }
1469             $output .= html_writer::script($js);
1470         }
1471
1472         $inyuijs = $this->get_javascript_code(false);
1473         $ondomreadyjs = $this->get_javascript_code(true);
1474         $jsinit = $this->get_javascript_init_code();
1475         $handlersjs = $this->get_event_handler_code();
1476
1477         // There is no global Y, make sure it is available in your scope.
1478         $js = "YUI().use('node', function(Y) {\n{$inyuijs}{$ondomreadyjs}{$jsinit}{$handlersjs}\n});";
1479
1480         $output .= html_writer::script($js);
1481
1482         return $output;
1483     }
1484
1485     /**
1486      * Have we already output the code in the <head> tag?
1487      *
1488      * @return bool
1489      */
1490     public function is_head_done() {
1491         return $this->headdone;
1492     }
1493
1494     /**
1495      * Have we already output the code at the start of the <body> tag?
1496      *
1497      * @return bool
1498      */
1499     public function is_top_of_body_done() {
1500         return $this->topofbodydone;
1501     }
1502
1503     /**
1504      * Should we generate a bit of content HTML that is only required once  on
1505      * this page (e.g. the contents of the modchooser), now? Basically, we call
1506      * {@link has_one_time_item_been_created()}, and if the thing has not already
1507      * been output, we return true to tell the caller to generate it, and also
1508      * call {@link set_one_time_item_created()} to record the fact that it is
1509      * about to be generated.
1510      *
1511      * That is, a typical usage pattern (in a renderer method) is:
1512      * <pre>
1513      * if (!$this->page->requires->should_create_one_time_item_now($thing)) {
1514      *     return '';
1515      * }
1516      * // Else generate it.
1517      * </pre>
1518      *
1519      * @param string $thing identifier for the bit of content. Should be of the form
1520      *      frankenstyle_things, e.g. core_course_modchooser.
1521      * @return bool if true, the caller should generate that bit of output now, otherwise don't.
1522      */
1523     public function should_create_one_time_item_now($thing) {
1524         if ($this->has_one_time_item_been_created($thing)) {
1525             return false;
1526         }
1527
1528         $this->set_one_time_item_created($thing);
1529         return true;
1530     }
1531
1532     /**
1533      * Has a particular bit of HTML that is only required once  on this page
1534      * (e.g. the contents of the modchooser) already been generated?
1535      *
1536      * Normally, you can use the {@link should_create_one_time_item_now()} helper
1537      * method rather than calling this method directly.
1538      *
1539      * @param string $thing identifier for the bit of content. Should be of the form
1540      *      frankenstyle_things, e.g. core_course_modchooser.
1541      * @return bool whether that bit of output has been created.
1542      */
1543     public function has_one_time_item_been_created($thing) {
1544         return isset($this->onetimeitemsoutput[$thing]);
1545     }
1546
1547     /**
1548      * Indicate that a particular bit of HTML that is only required once on this
1549      * page (e.g. the contents of the modchooser) has been generated (or is about to be)?
1550      *
1551      * Normally, you can use the {@link should_create_one_time_item_now()} helper
1552      * method rather than calling this method directly.
1553      *
1554      * @param string $thing identifier for the bit of content. Should be of the form
1555      *      frankenstyle_things, e.g. core_course_modchooser.
1556      */
1557     public function set_one_time_item_created($thing) {
1558         if ($this->has_one_time_item_been_created($thing)) {
1559             throw new coding_exception($thing . ' is only supposed to be ouput ' .
1560                     'once per page, but it seems to be being output again.');
1561         }
1562         return $this->onetimeitemsoutput[$thing] = true;
1563     }
1564 }
1565
1566 /**
1567  * This class represents the YUI configuration.
1568  *
1569  * @copyright 2013 Andrew Nicols
1570  * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
1571  * @since Moodle 2.5
1572  * @package core
1573  * @category output
1574  */
1575 class YUI_config {
1576     /**
1577      * These settings must be public so that when the object is converted to json they are exposed.
1578      * Note: Some of these are camelCase because YUI uses camelCase variable names.
1579      *
1580      * The settings are described and documented in the YUI API at:
1581      * - http://yuilibrary.com/yui/docs/api/classes/config.html
1582      * - http://yuilibrary.com/yui/docs/api/classes/Loader.html
1583      */
1584     public $debug = false;
1585     public $base;
1586     public $comboBase;
1587     public $combine;
1588     public $filter = null;
1589     public $insertBefore = 'firstthemesheet';
1590     public $groups = array();
1591     public $modules = array();
1592
1593     /**
1594      * @var array List of functions used by the YUI Loader group pattern recognition.
1595      */
1596     protected $jsconfigfunctions = array();
1597
1598     /**
1599      * Create a new group within the YUI_config system.
1600      *
1601      * @param String $name The name of the group. This must be unique and
1602      * not previously used.
1603      * @param Array $config The configuration for this group.
1604      * @return void
1605      */
1606     public function add_group($name, $config) {
1607         if (isset($this->groups[$name])) {
1608             throw new coding_exception("A YUI configuration group for '{$name}' already exists. To make changes to this group use YUI_config->update_group().");
1609         }
1610         $this->groups[$name] = $config;
1611     }
1612
1613     /**
1614      * Update an existing group configuration
1615      *
1616      * Note, any existing configuration for that group will be wiped out.
1617      * This includes module configuration.
1618      *
1619      * @param String $name The name of the group. This must be unique and
1620      * not previously used.
1621      * @param Array $config The configuration for this group.
1622      * @return void
1623      */
1624     public function update_group($name, $config) {
1625         if (!isset($this->groups[$name])) {
1626             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.');
1627         }
1628         $this->groups[$name] = $config;
1629     }
1630
1631     /**
1632      * Set the value of a configuration function used by the YUI Loader's pattern testing.
1633      *
1634      * Only the body of the function should be passed, and not the whole function wrapper.
1635      *
1636      * The JS function your write will be passed a single argument 'name' containing the
1637      * name of the module being loaded.
1638      *
1639      * @param $function String the body of the JavaScript function. This should be used i
1640      * @return String the name of the function to use in the group pattern configuration.
1641      */
1642     public function set_config_function($function) {
1643         $configname = 'yui' . (count($this->jsconfigfunctions) + 1) . 'ConfigFn';
1644         if (isset($this->jsconfigfunctions[$configname])) {
1645             throw new coding_exception("A YUI config function with this name already exists. Config function names must be unique.");
1646         }
1647         $this->jsconfigfunctions[$configname] = $function;
1648         return '@' . $configname . '@';
1649     }
1650
1651     /**
1652      * Allow setting of the config function described in {@see set_config_function} from a file.
1653      * The contents of this file are then passed to set_config_function.
1654      *
1655      * When jsrev is positive, the function is minified and stored in a MUC cache for subsequent uses.
1656      *
1657      * @param $file The path to the JavaScript function used for YUI configuration.
1658      * @return String the name of the function to use in the group pattern configuration.
1659      */
1660     public function set_config_source($file) {
1661         global $CFG;
1662         $cache = cache::make('core', 'yuimodules');
1663
1664         // Attempt to get the metadata from the cache.
1665         $keyname = 'configfn_' . $file;
1666         $fullpath = $CFG->dirroot . '/' . $file;
1667         if (!isset($CFG->jsrev) || $CFG->jsrev == -1) {
1668             $cache->delete($keyname);
1669             $configfn = file_get_contents($fullpath);
1670         } else {
1671             $configfn = $cache->get($keyname);
1672             if ($configfn === false) {
1673                 require_once($CFG->libdir . '/jslib.php');
1674                 $configfn = core_minify::js_files(array($fullpath));
1675                 $cache->set($keyname, $configfn);
1676             }
1677         }
1678         return $this->set_config_function($configfn);
1679     }
1680
1681     /**
1682      * Retrieve the list of JavaScript functions for YUI_config groups.
1683      *
1684      * @return String The complete set of config functions
1685      */
1686     public function get_config_functions() {
1687         $configfunctions = '';
1688         foreach ($this->jsconfigfunctions as $functionname => $function) {
1689             $configfunctions .= "var {$functionname} = function(me) {";
1690             $configfunctions .= $function;
1691             $configfunctions .= "};\n";
1692         }
1693         return $configfunctions;
1694     }
1695
1696     /**
1697      * Update the header JavaScript with any required modification for the YUI Loader.
1698      *
1699      * @param $js String The JavaScript to manipulate.
1700      * @return String the modified JS string.
1701      */
1702     public function update_header_js($js) {
1703         // Update the names of the the configFn variables.
1704         // The PHP json_encode function cannot handle literal names so we have to wrap
1705         // them in @ and then replace them with literals of the same function name.
1706         foreach ($this->jsconfigfunctions as $functionname => $function) {
1707             $js = str_replace('"@' . $functionname . '@"', $functionname, $js);
1708         }
1709         return $js;
1710     }
1711
1712     /**
1713      * Add configuration for a specific module.
1714      *
1715      * @param String $name The name of the module to add configuration for.
1716      * @param Array $config The configuration for the specified module.
1717      * @param String $group The name of the group to add configuration for.
1718      * If not specified, then this module is added to the global
1719      * configuration.
1720      * @return void
1721      */
1722     public function add_module_config($name, $config, $group = null) {
1723         if ($group) {
1724             if (!isset($this->groups[$name])) {
1725                 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.');
1726             }
1727             if (!isset($this->groups[$group]['modules'])) {
1728                 $this->groups[$group]['modules'] = array();
1729             }
1730             $modules = &$this->groups[$group]['modules'];
1731         } else {
1732             $modules = &$this->modules;
1733         }
1734         $modules[$name] = $config;
1735     }
1736
1737     /**
1738      * Add the moodle YUI module metadata for the moodle group to the YUI_config instance.
1739      *
1740      * If js caching is disabled, metadata will not be served causing YUI to calculate
1741      * module dependencies as each module is loaded.
1742      *
1743      * If metadata does not exist it will be created and stored in a MUC entry.
1744      *
1745      * @return void
1746      */
1747     public function add_moodle_metadata() {
1748         global $CFG;
1749         if (!isset($this->groups['moodle'])) {
1750             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.');
1751         }
1752
1753         if (!isset($this->groups['moodle']['modules'])) {
1754             $this->groups['moodle']['modules'] = array();
1755         }
1756
1757         $cache = cache::make('core', 'yuimodules');
1758         if (!isset($CFG->jsrev) || $CFG->jsrev == -1) {
1759             $metadata = array();
1760             $metadata = $this->get_moodle_metadata();
1761             $cache->delete('metadata');
1762         } else {
1763             // Attempt to get the metadata from the cache.
1764             if (!$metadata = $cache->get('metadata')) {
1765                 $metadata = $this->get_moodle_metadata();
1766                 $cache->set('metadata', $metadata);
1767             }
1768         }
1769
1770         // Merge with any metadata added specific to this page which was added manually.
1771         $this->groups['moodle']['modules'] = array_merge($this->groups['moodle']['modules'],
1772                 $metadata);
1773     }
1774
1775     /**
1776      * Determine the module metadata for all moodle YUI modules.
1777      *
1778      * This works through all modules capable of serving YUI modules, and attempts to get
1779      * metadata for each of those modules.
1780      *
1781      * @return Array of module metadata
1782      */
1783     private function get_moodle_metadata() {
1784         $moodlemodules = array();
1785         // Core isn't a plugin type or subsystem - handle it seperately.
1786         if ($module = $this->get_moodle_path_metadata(core_component::get_component_directory('core'))) {
1787             $moodlemodules = array_merge($moodlemodules, $module);
1788         }
1789
1790         // Handle other core subsystems.
1791         $subsystems = core_component::get_core_subsystems();
1792         foreach ($subsystems as $subsystem => $path) {
1793             if (is_null($path)) {
1794                 continue;
1795             }
1796             if ($module = $this->get_moodle_path_metadata($path)) {
1797                 $moodlemodules = array_merge($moodlemodules, $module);
1798             }
1799         }
1800
1801         // And finally the plugins.
1802         $plugintypes = core_component::get_plugin_types();
1803         foreach ($plugintypes as $plugintype => $pathroot) {
1804             $pluginlist = core_component::get_plugin_list($plugintype);
1805             foreach ($pluginlist as $plugin => $path) {
1806                 if ($module = $this->get_moodle_path_metadata($path)) {
1807                     $moodlemodules = array_merge($moodlemodules, $module);
1808                 }
1809             }
1810         }
1811
1812         return $moodlemodules;
1813     }
1814
1815     /**
1816      * Helper function process and return the YUI metadata for all of the modules under the specified path.
1817      *
1818      * @param String $path the UNC path to the YUI src directory.
1819      * @return Array the complete array for frankenstyle directory.
1820      */
1821     private function get_moodle_path_metadata($path) {
1822         // Add module metadata is stored in frankenstyle_modname/yui/src/yui_modname/meta/yui_modname.json.
1823         $baseyui = $path . '/yui/src';
1824         $modules = array();
1825         if (is_dir($baseyui)) {
1826             $items = new DirectoryIterator($baseyui);
1827             foreach ($items as $item) {
1828                 if ($item->isDot() or !$item->isDir()) {
1829                     continue;
1830                 }
1831                 $metafile = realpath($baseyui . '/' . $item . '/meta/' . $item . '.json');
1832                 if (!is_readable($metafile)) {
1833                     continue;
1834                 }
1835                 $metadata = file_get_contents($metafile);
1836                 $modules = array_merge($modules, (array) json_decode($metadata));
1837             }
1838         }
1839         return $modules;
1840     }
1841
1842     /**
1843      * Define YUI modules which we have been required to patch between releases.
1844      *
1845      * We must do this because we aggressively cache content on the browser, and we must also override use of the
1846      * external CDN which will serve the true authoritative copy of the code without our patches.
1847      *
1848      * @param String combobase The local combobase
1849      * @param String yuiversion The current YUI version
1850      * @param Int patchlevel The patch level we're working to for YUI
1851      * @param Array patchedmodules An array containing the names of the patched modules
1852      * @return void
1853      */
1854     public function define_patched_core_modules($combobase, $yuiversion, $patchlevel, $patchedmodules) {
1855         // The version we use is suffixed with a patchlevel so that we can get additional revisions between YUI releases.
1856         $subversion = $yuiversion . '_' . $patchlevel;
1857
1858         if ($this->comboBase == $combobase) {
1859             // If we are using the local combobase in the loader, we can add a group and still make use of the combo
1860             // loader. We just need to specify a different root which includes a slightly different YUI version number
1861             // to include our patchlevel.
1862             $patterns = array();
1863             $modules = array();
1864             foreach ($patchedmodules as $modulename) {
1865                 // We must define the pattern and module here so that the loader uses our group configuration instead of
1866                 // the standard module definition. We may lose some metadata provided by upstream but this will be
1867                 // loaded when the module is loaded anyway.
1868                 $patterns[$modulename] = array(
1869                     'group' => 'yui-patched',
1870                 );
1871                 $modules[$modulename] = array();
1872             }
1873
1874             // Actually add the patch group here.
1875             $this->add_group('yui-patched', array(
1876                 'combine' => true,
1877                 'root' => $subversion . '/',
1878                 'patterns' => $patterns,
1879                 'modules' => $modules,
1880             ));
1881
1882         } else {
1883             // The CDN is in use - we need to instead use the local combobase for this module and override the modules
1884             // definition. We cannot use the local base - we must use the combobase because we cannot invalidate the
1885             // local base in browser caches.
1886             $fullpathbase = $combobase . $subversion . '/';
1887             foreach ($patchedmodules as $modulename) {
1888                 $this->modules[$modulename] = array(
1889                     'fullpath' => $fullpathbase . $modulename . '/' . $modulename . '-min.js'
1890                 );
1891             }
1892         }
1893     }
1894 }
1895
1896 /**
1897  * Invalidate all server and client side JS caches.
1898  */
1899 function js_reset_all_caches() {
1900     global $CFG;
1901
1902     $next = time();
1903     if (isset($CFG->jsrev) and $next <= $CFG->jsrev and $CFG->jsrev - $next < 60*60) {
1904         // This resolves problems when reset is requested repeatedly within 1s,
1905         // the < 1h condition prevents accidental switching to future dates
1906         // because we might not recover from it.
1907         $next = $CFG->jsrev+1;
1908     }
1909
1910     set_config('jsrev', $next);
1911 }