lib/outputrequirementslib.php

   1 <?php
   2
   3 // This file is part of Moodle - http://moodle.org/
   4 //
   5 // Moodle is free software: you can redistribute it and/or modify
   6 // it under the terms of the GNU General Public License as published by
   7 // the Free Software Foundation, either version 3 of the License, or
   8 // (at your option) any later version.
   9 //
  10 // Moodle is distributed in the hope that it will be useful,
  11 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 // GNU General Public License for more details.
  14 //
  15 // You should have received a copy of the GNU General Public License
  16 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  17
  18
  19 /**
  20  * Library functions to facilitate the use of JavaScript in Moodle.
  21  *
  22  * @package    core
  23  * @subpackage lib
  24  * @copyright  2009 Tim Hunt, 2010 Petr Skoda
  25  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  26  */
  27
  28 defined('MOODLE_INTERNAL') || die();
  29
  30 // note: you can find history of this file in lib/ajax/ajaxlib.php
  31
  32 /**
  33  * This class tracks all the things that are needed by the current page.
  34  *
  35  * Normally, the only instance of this  class you will need to work with is the
  36  * one accessible via $PAGE->requires.
  37  *
  38  * Typical usage would be
  39  * <pre>
  40  *     $PAGE->requires->js_init_call('M.mod_forum.init_view');
  41  * </pre>
  42  *
  43  * It also supports obsoleted coding style withouth YUI3 modules.
  44  * <pre>
  45  *     $PAGE->requires->css('/mod/mymod/userstyles.php?id='.$id); // not overridable via themes!
  46  *     $PAGE->requires->js('/mod/mymod/script.js');
  47  *     $PAGE->requires->js('/mod/mymod/small_but_urgent.js', true);
  48  *     $PAGE->requires->js_function_call('init_mymod', array($data), true);
  49  * </pre>
  50  *
  51  * There are some natural restrictions on some methods. For example, {@link css()}
  52  * can only be called before the <head> tag is output. See the comments on the
  53  * individual methods for details.
  54  *
  55  * @copyright 2009 Tim Hunt, 2010 Petr Skoda
  56  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  57  * @since Moodle 2.0
  58  */
  59 class page_requirements_manager {
  60     /** List of string available from JS */
  61     protected $stringsforjs = array();
  62     /** List of JS variables to be initialised */
  63     protected $jsinitvariables = array('head'=>array(), 'footer'=>array());
  64     /** Included JS scripts */
  65     protected $jsincludes = array('head'=>array(), 'footer'=>array());
  66     /** List of needed function calls */
  67     protected $jscalls = array('normal'=>array(), 'ondomready'=>array());
  68     /**
  69      * List of skip links, those are needed for accessibility reasons
  70      * @var array
  71      */
  72     protected $skiplinks = array();
  73     /**
  74      * Javascript code used for initialisation of page, it should be relatively small
  75      * @var array
  76      */
  77     protected $jsinitcode = array();
  78     /**
  79      * Theme sheets, initialised only from core_renderer
  80      * @var array of moodle_url
  81      */
  82     protected $cssthemeurls = array();
  83     /**
  84      * List of custom theme sheets, these are strongly discouraged!
  85      * Useful mostly only for CSS submitted by teachers that is not part of the theme.
  86      * @var array of moodle_url
  87      */
  88     protected $cssurls = array();
  89     /**
  90      * List of requested event handlers
  91      * @var array
  92      */
  93     protected $eventhandlers = array();
  94     /**
  95      * Extra modules
  96      * @var array
  97      */
  98     protected $extramodules = array();
  99     /** Flag indicated head stuff already printed */
 100     protected $headdone = false;
 101     /** Flag indicating top of body already printed */
 102     protected $topofbodydone = false;
 103
 104     /** YUI PHPLoader instance responsible for YUI2 loading from PHP only */
 105     protected $yui2loader;
 106     /** YUI PHPLoader instance responsible for YUI3 loading from PHP only */
 107     protected $yui3loader;
 108     /** YUI PHPLoader instance responsible for YUI3 loading from javascript */
 109     protected $M_yui_loader;
 110     /** some config vars exposed in JS, please no secret stuff there */
 111     protected $M_cfg;
 112     /** stores debug backtraces from when JS modules were included in the page */
 113     protected $debug_moduleloadstacktraces = array();
 114
 115     /**
 116      * Page requirements constructor.
 117      */
 118     public function __construct() {
 119         global $CFG;
 120
 121         require_once("$CFG->libdir/yui/phploader/phploader/loader.php");
 122
 123         $this->yui3loader = new YAHOO_util_Loader($CFG->yui3version);
 124         $this->yui2loader = new YAHOO_util_Loader($CFG->yui2version);
 125
 126         // set up some loader options
 127         if (debugging('', DEBUG_DEVELOPER)) {
 128             $this->yui3loader->filter = YUI_RAW; // for more detailed logging info use YUI_DEBUG here
 129             $this->yui2loader->filter = YUI_RAW; // for more detailed logging info use YUI_DEBUG here
 130         } else {
 131             $this->yui3loader->filter = null;
 132             $this->yui2loader->filter = null;
 133         }
 134         if (!empty($CFG->useexternalyui)) {
 135             $this->yui3loader->base = 'http://yui.yahooapis.com/' . $CFG->yui3version . '/build/';
 136             $this->yui2loader->base = 'http://yui.yahooapis.com/' . $CFG->yui2version . '/build/';
 137             $this->yui3loader->comboBase = 'http://yui.yahooapis.com/combo?';
 138             $this->yui2loader->comboBase = 'http://yui.yahooapis.com/combo?';
 139         } else {
 140             $this->yui3loader->base = $CFG->httpswwwroot . '/lib/yui/'. $CFG->yui3version . '/build/';
 141             $this->yui2loader->base = $CFG->httpswwwroot . '/lib/yui/'. $CFG->yui2version . '/build/';
 142             $this->yui3loader->comboBase = $CFG->httpswwwroot . '/theme/yui_combo.php?';
 143             $this->yui2loader->comboBase = $CFG->httpswwwroot . '/theme/yui_combo.php?';
 144         }
 145
 146         // enable combo loader? this significantly helps with caching and performance!
 147         $this->yui3loader->combine = !empty($CFG->yuicomboloading);
 148         $this->yui2loader->combine = !empty($CFG->yuicomboloading);
 149
 150         if (empty($CFG->cachejs)) {
 151             $jsrev = -1;
 152         } else if (empty($CFG->jsrev)) {
 153             $jsrev = 1;
 154         } else {
 155             $jsrev = $CFG->jsrev;
 156         }
 157
 158         // set up JS YUI loader helper object
 159         $this->M_yui_loader = new stdClass();
 160         $this->M_yui_loader->base         = $this->yui3loader->base;
 161         $this->M_yui_loader->comboBase    = $this->yui3loader->comboBase;
 162         $this->M_yui_loader->combine      = $this->yui3loader->combine;
 163         $this->M_yui_loader->filter       = ($this->yui3loader->filter == YUI_DEBUG) ? 'debug' : '';
 164         $this->M_yui_loader->insertBefore = 'firstthemesheet';
 165         $this->M_yui_loader->modules      = array();
 166         $this->M_yui_loader->groups       = array(
 167             'moodle' => array(
 168                 'name' => 'moodle',
 169                 'base' => $CFG->httpswwwroot . '/theme/yui_combo.php?moodle/'.$jsrev.'/',
 170                 'comboBase' => $CFG->httpswwwroot . '/theme/yui_combo.php?',
 171                 'combine' => $this->yui3loader->combine,
 172                 'filter' => '',
 173                 'ext' => false,
 174                 'root' => 'moodle/'.$jsrev.'/', // Add the rev to the root path so that we can control caching
 175                 'patterns' => array(
 176                     'moodle-' => array(
 177                         'group' => 'moodle',
 178                         'configFn' => '@MOODLECONFIGFN@'
 179                     ),
 180                     'root' => 'moodle'
 181                 )
 182             ),
 183             'local' => array(
 184                 'name' => 'gallery',
 185                 'base' => $CFG->wwwroot.'/lib/yui/gallery/',
 186                 'comboBase' => $CFG->httpswwwroot . '/theme/yui_combo.php?',
 187                 'combine' => $this->yui3loader->combine,
 188                 'filter' => $this->M_yui_loader->filter,
 189                 'ext' => false,
 190                 'root' => 'gallery/',
 191                 'patterns' => array(
 192                     'gallery-' => array(
 193                         'group' => 'gallery',
 194                         'configFn' => '@GALLERYCONFIGFN@',
 195                     ),
 196                     'root' => 'gallery'
 197                 )
 198             )
 199         );
 200         $this->add_yui2_modules(); // adds loading info for all YUI2 modules
 201         $this->js_module($this->find_module('core_filepicker'));
 202         $this->js_module($this->find_module('core_dock'));
 203
 204         // YUI3 init code
 205         $libs = array('cssreset', 'cssbase', 'cssfonts', 'cssgrids', 'node', 'loader'); // full CSS reset + basic libs
 206         foreach ($libs as $lib) {
 207             $this->yui3loader->load($lib);
 208         }
 209     }
 210
 211     /**
 212      * This method adds yui2 modules into the yui3 JS loader-
 213      * @return void
 214      */
 215     protected function add_yui2_modules() {
 216         //note: this function is definitely not perfect, because
 217         //      it adds tons of markup into each page, but it can be
 218         //      abstracted into separate JS file with proper headers
 219         global $CFG;
 220
 221         $GLOBALS['yui_current'] = array();
 222         require($CFG->libdir.'/yui/phploader/lib/meta/config_'.$CFG->yui2version.'.php');
 223         $info = $GLOBALS['yui_current'];
 224         unset($GLOBALS['yui_current']);
 225
 226         if (empty($CFG->yuicomboloading)) {
 227             $urlbase = $this->yui2loader->base;
 228         } else {
 229             $urlbase = $this->yui2loader->comboBase.$CFG->yui2version.'/build/';
 230         }
 231
 232         $modules = array();
 233         $ignored = array(); // list of CSS modules that are not needed
 234         foreach ($info['moduleInfo'] as $name => $module) {
 235             if ($module['type'] === 'css') {
 236                 $ignored[$name] = true;
 237             } else {
 238                 $modules['yui2-'.$name] = $module;
 239             }
 240         }
 241         foreach ($modules as $name=>$module) {
 242             $module['fullpath'] = $urlbase.$module['path']; // fix path to point to correct location
 243             unset($module['path']);
 244             unset($module['skinnable']); // we load all YUI2 css automatically, this prevents weird missing css loader problems
 245             foreach(array('requires', 'optional', 'supersedes') as $fixme) {
 246                 if (!empty($module[$fixme])) {
 247                     $fixed = false;
 248                     foreach ($module[$fixme] as $key=>$dep) {
 249                         if (isset($ignored[$dep])) {
 250                             unset($module[$fixme][$key]);
 251                             $fixed = true;
 252                         } else {
 253                             $module[$fixme][$key] = 'yui2-'.$dep;
 254                         }
 255                     }
 256                     if ($fixed) {
 257                         $module[$fixme] = array_merge($module[$fixme]); // fix keys
 258                     }
 259                 }
 260             }
 261             $this->M_yui_loader->modules[$name] = $module;
 262             if (debugging('', DEBUG_DEVELOPER)) {
 263                 if (!array_key_exists($name, $this->debug_moduleloadstacktraces)) {
 264                     $this->debug_moduleloadstacktraces[$name] = array();
 265                 }
 266                 $this->debug_moduleloadstacktraces[$name][] = format_backtrace(debug_backtrace());
 267             }
 268         }
 269     }
 270
 271     /**
 272      * Initialise with the bits of JavaScript that every Moodle page should have.
 273      *
 274      * @param moodle_page $page
 275      * @param core_renderer $output
 276      */
 277     protected function init_requirements_data(moodle_page $page, core_renderer $renderer) {
 278         global $CFG;
 279
 280         // JavaScript should always work with $CFG->httpswwwroot rather than $CFG->wwwroot.
 281         // Otherwise, in some situations, users will get warnings about insecure content
 282         // on secure pages from their web browser.
 283
 284         $this->M_cfg = array(
 285             'wwwroot'             => $CFG->httpswwwroot, // Yes, really. See above.
 286             'sesskey'             => sesskey(),
 287             'loadingicon'         => $renderer->pix_url('i/loading_small', 'moodle')->out(false),
 288             'themerev'            => theme_get_revision(),
 289             'theme'               => $page->theme->name,
 290             'jsrev'               => ((empty($CFG->cachejs) or empty($CFG->jsrev)) ? -1 : $CFG->jsrev),
 291         );
 292         if (debugging('', DEBUG_DEVELOPER)) {
 293             $this->M_cfg['developerdebug'] = true;
 294             $this->yui2_lib('logger');
 295         }
 296
 297         // accessibility stuff
 298         $this->skip_link_to('maincontent', get_string('tocontent', 'access'));
 299
 300         // to be removed soon
 301         $this->yui2_lib('dom');        // at least javascript-static.js needs to be migrated to YUI3
 302
 303         $this->string_for_js('confirmation', 'admin');
 304         $this->string_for_js('cancel', 'moodle');
 305         $this->string_for_js('yes', 'moodle');
 306
 307         if ($page->pagelayout === 'frametop') {
 308             $this->js_init_call('M.util.init_frametop');
 309         }
 310     }
 311
 312     /**
 313      * Ensure that the specified JavaScript file is linked to from this page.
 314      *
 315      * NOTE: This function is to be used in rare cases only, please store your JS in module.js file
 316      * and use $PAGE->requires->js_init_call() instead.
 317      *
 318      * By default the link is put at the end of the page, since this gives best page-load performance.
 319      *
 320      * Even if a particular script is requested more than once, it will only be linked
 321      * to once.
 322      *
 323      * @param string|moodle_url $url The path to the .js file, relative to $CFG->dirroot / $CFG->wwwroot.
 324      *      For example '/mod/mymod/customscripts.js'; use moodle_url for external scripts
 325      * @param bool $inhead initialise in head
 326      * @return void
 327      */
 328     public function js($url, $inhead=false) {
 329         $url = $this->js_fix_url($url);
 330         $where = $inhead ? 'head' : 'footer';
 331         $this->jsincludes[$where][$url->out()] = $url;
 332     }
 333
 334     /**
 335      * Ensure that the specified YUI2 library file, and all its required dependencies,
 336      * are linked to from this page.
 337      *
 338      * By default the link is put at the end of the page, since this gives best page-load
 339      * performance. Optional dependencies are not loaded automatically - if you want
 340      * them you will need to load them first with other calls to this method.
 341      *
 342      * Even if a particular library is requested more than once (perhaps as a dependency
 343      * of other libraries) it will only be linked to once.
 344      *
 345      * The library is leaded as soon as possible, if $OUTPUT->header() not used yet it
 346      * is put into the page header, otherwise it is loaded in the page footer.
 347      *
 348      * @param string|array $libname the name of the YUI2 library you require. For example 'autocomplete'.
 349      * @return void
 350      */
 351     public function yui2_lib($libname) {
 352         $libnames = (array)$libname;
 353         foreach ($libnames as $lib) {
 354             $this->yui2loader->load($lib);
 355         }
 356     }
 357
 358     /**
 359      * Returns the actual url through which a script is served.
 360      * @param moodle_url|string $url full moodle url, or shortened path to script
 361      * @return moodle_url
 362      */
 363     protected function js_fix_url($url) {
 364         global $CFG;
 365
 366         if ($url instanceof moodle_url) {
 367             return $url;
 368         } else if (strpos($url, '/') === 0) {
 369             if (debugging()) {
 370                 // check file existence only when in debug mode
 371                 if (!file_exists($CFG->dirroot . strtok($url, '?'))) {
 372                     throw new coding_exception('Attempt to require a JavaScript file that does not exist.', $url);
 373                 }
 374             }
 375             if (!empty($CFG->cachejs) and !empty($CFG->jsrev) and strpos($url, '/lib/editor/') !== 0 and substr($url, -3) === '.js') {
 376                 return new moodle_url($CFG->httpswwwroot.'/lib/javascript.php', array('file'=>$url, 'rev'=>$CFG->jsrev));
 377             } else {
 378                 return new moodle_url($CFG->httpswwwroot.$url);
 379             }
 380         } else {
 381             throw new coding_exception('Invalid JS url, it has to be shortened url starting with / or moodle_url instance.', $url);
 382         }
 383     }
 384
 385     /**
 386      * Find out if JS module present and return details.
 387      * @param string $component name of component in frankenstyle, ex: core_group, mod_forum
 388      * @return array description of module or null if not found
 389      */
 390     protected function find_module($component) {
 391         global $CFG;
 392
 393         $module = null;
 394
 395
 396         if (strpos($component, 'core_') === 0) {
 397             // must be some core stuff - list here is not complete, this is just the stuff used from multiple places
 398             // so that we do nto have to repeat the definition of these modules over and over again
 399             switch($component) {
 400                 case 'core_filepicker':
 401                     $module = array('name'     => 'core_filepicker',
 402                                     'fullpath' => '/repository/filepicker.js',
 403                                     'requires' => array('base', 'node', 'node-event-simulate', 'json', 'async-queue', 'io', 'yui2-button', 'yui2-container', 'yui2-layout', 'yui2-menu', 'yui2-treeview', 'yui2-dragdrop', 'yui2-cookie'),
 404                                     'strings'  => array(array('add', 'repository'), array('back', 'repository'), array('cancel', 'moodle'), array('close', 'repository'),
 405                                                         array('cleancache', 'repository'), array('copying', 'repository'), array('date', 'repository'), array('downloadsucc', 'repository'),
 406                                                         array('emptylist', 'repository'), array('error', 'repository'), array('federatedsearch', 'repository'),
 407                                                         array('filenotnull', 'repository'), array('getfile', 'repository'), array('help', 'moodle'), array('iconview', 'repository'),
 408                                                         array('invalidjson', 'repository'), array('linkexternal', 'repository'), array('listview', 'repository'),
 409                                                         array('loading', 'repository'), array('login', 'repository'), array('logout', 'repository'), array('noenter', 'repository'),
 410                                                         array('noresult', 'repository'), array('manageurl', 'repository'), array('popup', 'repository'), array('preview', 'repository'),
 411                                                         array('refresh', 'repository'), array('save', 'repository'), array('saveas', 'repository'), array('saved', 'repository'),
 412                                                         array('saving', 'repository'), array('search', 'repository'), array('searching', 'repository'), array('size', 'repository'),
 413                                                         array('submit', 'repository'), array('sync', 'repository'), array('title', 'repository'), array('upload', 'repository'),
 414                                                         array('uploading', 'repository'), array('xhtmlerror', 'repository'),
 415                                                         array('cancel'), array('chooselicense', 'repository'), array('author', 'repository'),
 416                                                         array('ok', 'moodle'), array('error', 'moodle'), array('info', 'moodle'), array('norepositoriesavailable', 'repository'), array('norepositoriesexternalavailable', 'repository'),
 417                                                         array('nofilesattached', 'repository'), array('filepicker', 'repository'),
 418                                                         array('nofilesavailable', 'repository'), array('overwrite', 'repository'),
 419                                                         array('renameto', 'repository'), array('fileexists', 'repository'),
 420                                                         array('fileexistsdialogheader', 'repository'), array('fileexistsdialog_editor', 'repository'),
 421                                                         array('fileexistsdialog_filemanager', 'repository')
 422                                                     ));
 423                     break;
 424                 case 'core_comment':
 425                     $module = array('name'     => 'core_comment',
 426                                     'fullpath' => '/comment/comment.js',
 427                                     'requires' => array('base', 'io', 'node', 'json', 'yui2-animation', 'overlay'),
 428                                     'strings' => array(array('confirmdeletecomments', 'admin'), array('yes', 'moodle'), array('no', 'moodle'))
 429                                 );
 430                     break;
 431                 case 'core_role':
 432                     $module = array('name'     => 'core_role',
 433                                     'fullpath' => '/admin/roles/module.js',
 434                                     'requires' => array('node', 'cookie'));
 435                     break;
 436                 case 'core_completion':
 437                     $module = array('name'     => 'core_completion',
 438                                     'fullpath' => '/course/completion.js');
 439                     break;
 440                 case 'core_dock':
 441                     $module = array('name'     => 'core_dock',
 442                                     'fullpath' => '/blocks/dock.js',
 443                                     'requires' => array('base', 'node', 'event-custom', 'event-mouseenter', 'event-resize'),
 444                                     'strings' => array(array('addtodock', 'block'),array('undockitem', 'block'),array('undockall', 'block'),array('thisdirectionvertical', 'langconfig')));
 445                     break;
 446                 case 'core_message':
 447                     $module = array('name'     => 'core_message',
 448                                     'requires' => array('base', 'node', 'event', 'node-event-simulate'),
 449                                     'fullpath' => '/message/module.js');
 450                     break;
 451                 case 'core_flashdetect':
 452                     $module = array('name'     => 'core_flashdetect',
 453                                     'fullpath' => '/lib/flashdetect/flashdetect.js',
 454                                     'requires' => array('io'));
 455                     break;
 456                 case 'core_group':
 457                     $module = array('name'     => 'core_group',
 458                                     'fullpath' => '/group/module.js',
 459                                     'requires' => array('node', 'overlay', 'event-mouseenter'));
 460                     break;
 461                 case 'core_question_engine':
 462                     $module = array('name'     => 'core_question_engine',
 463                                     'fullpath' => '/question/qengine.js',
 464                                     'requires' => array('node', 'event'));
 465                     break;
 466                 case 'core_rating':
 467                     $module = array('name'     => 'core_rating',
 468                                     'fullpath' => '/rating/module.js',
 469                                     'requires' => array('node', 'event', 'overlay', 'io', 'json'));
 470                     break;
 471                 case 'core_filetree':
 472                     $module = array('name'     => 'core_filetree',
 473                                     'fullpath' => '/files/module.js',
 474                                     'requires' => array('node', 'event', 'overlay', 'io', 'json', 'yui2-treeview'));
 475                     break;
 476             }
 477
 478         } else {
 479             if ($dir = get_component_directory($component)) {
 480                 if (file_exists("$dir/module.js")) {
 481                     if (strpos($dir, $CFG->dirroot.'/') === 0) {
 482                         $dir = substr($dir, strlen($CFG->dirroot));
 483                         $module = array('name'=>$component, 'fullpath'=>"$dir/module.js", 'requires' => array());
 484                     }
 485                 }
 486             }
 487         }
 488
 489         return $module;
 490     }
 491
 492     /**
 493      * Append YUI3 module to default YUI3 JS loader.
 494      * The structure of module array is described at http://developer.yahoo.com/yui/3/yui/:
 495      * @param string|array $module name of module (details are autodetected), or full module specification as array
 496      * @return void
 497      */
 498     public function js_module($module) {
 499         global $CFG;
 500
 501         if (empty($module)) {
 502             throw new coding_exception('Missing YUI3 module name or full description.');
 503         }
 504
 505         if (is_string($module)) {
 506             $module = $this->find_module($module);
 507         }
 508
 509         if (empty($module) or empty($module['name']) or empty($module['fullpath'])) {
 510             throw new coding_exception('Missing YUI3 module details.');
 511         }
 512
 513         // Don't load this module if we already have, no need to!
 514         if ($this->js_module_loaded($module['name'])) {
 515             if (debugging('', DEBUG_DEVELOPER)) {
 516                 $this->debug_moduleloadstacktraces[$module['name']][] = format_backtrace(debug_backtrace());
 517             }
 518             return;
 519         }
 520
 521         $module['fullpath'] = $this->js_fix_url($module['fullpath'])->out(false);
 522         // add all needed strings
 523         if (!empty($module['strings'])) {
 524             foreach ($module['strings'] as $string) {
 525                 $identifier = $string[0];
 526                 $component = isset($string[1]) ? $string[1] : 'moodle';
 527                 $a = isset($string[2]) ? $string[2] : null;
 528                 $this->string_for_js($identifier, $component, $a);
 529             }
 530         }
 531         unset($module['strings']);
 532
 533         // Process module requirements and attempt to load each. This allows
 534         // moodle modules to require each other.
 535         if (!empty($module['requires'])){
 536             foreach ($module['requires'] as $requirement) {
 537                 $rmodule = $this->find_module($requirement);
 538                 if (is_array($rmodule)) {
 539                     $this->js_module($rmodule);
 540                 }
 541             }
 542         }
 543
 544         if ($this->headdone) {
 545             $this->extramodules[$module['name']] = $module;
 546         } else {
 547             $this->M_yui_loader->modules[$module['name']] = $module;
 548         }
 549         if (debugging('', DEBUG_DEVELOPER)) {
 550             if (!array_key_exists($module['name'], $this->debug_moduleloadstacktraces)) {
 551                 $this->debug_moduleloadstacktraces[$module['name']] = array();
 552             }
 553             $this->debug_moduleloadstacktraces[$module['name']][] = format_backtrace(debug_backtrace());
 554         }
 555     }
 556
 557     /**
 558      * Returns true if the module has already been loaded.
 559      *
 560      * @param string|array $modulename
 561      * @return bool True if the module has already been loaded
 562      */
 563     protected function js_module_loaded($module) {
 564         if (is_string($module)) {
 565             $modulename = $module;
 566         } else {
 567             $modulename = $module['name'];
 568         }
 569         return array_key_exists($modulename, $this->M_yui_loader->modules) ||
 570                array_key_exists($modulename, $this->extramodules);
 571     }
 572
 573     /**
 574      * Returns the stacktraces from loading js modules.
 575      * @return array
 576      */
 577     public function get_loaded_modules() {
 578         return $this->debug_moduleloadstacktraces;
 579     }
 580
 581     /**
 582      * Ensure that the specified CSS file is linked to from this page.
 583      *
 584      * Because stylesheet links must go in the <head> part of the HTML, you must call
 585      * this function before {@link get_head_code()} is called. That normally means before
 586      * the call to print_header. If you call it when it is too late, an exception
 587      * will be thrown.
 588      *
 589      * Even if a particular style sheet is requested more than once, it will only
 590      * be linked to once.
 591      *
 592      * Please note use of this feature is strongly discouraged,
 593      * it is suitable only for places where CSS is submitted directly by teachers.
 594      * (Students must not be allowed to submit any external CSS because it may
 595      * contain embedded javascript!). Example of correct use is mod/data.
 596      *
 597      * @param string $stylesheet The path to the .css file, relative to $CFG->wwwroot.
 598      *   For example:
 599      *      $PAGE->requires->css('mod/data/css.php?d='.$data->id);
 600      */
 601     public function css($stylesheet) {
 602         global $CFG;
 603
 604         if ($this->headdone) {
 605             throw new coding_exception('Cannot require a CSS file after &lt;head> has been printed.', $stylesheet);
 606         }
 607
 608         if ($stylesheet instanceof moodle_url) {
 609             // ok
 610         } else if (strpos($stylesheet, '/') === 0) {
 611             $stylesheet = new moodle_url($CFG->httpswwwroot.$stylesheet);
 612         } else {
 613             throw new coding_exception('Invalid stylesheet parameter.', $stylesheet);
 614         }
 615
 616         $this->cssurls[$stylesheet->out()] = $stylesheet; // overrides
 617     }
 618
 619     /**
 620      * Add theme stylkesheet to page - do not use from plugin code,
 621      * this should be called only from the core renderer!
 622      * @param moodle_url $stylesheet
 623      * @return void
 624      */
 625     public function css_theme(moodle_url $stylesheet) {
 626         $this->cssthemeurls[] = $stylesheet;
 627     }
 628
 629     /**
 630      * Ensure that a skip link to a given target is printed at the top of the <body>.
 631      *
 632      * You must call this function before {@link get_top_of_body_code()}, (if not, an exception
 633      * will be thrown). That normally means you must call this before the call to print_header.
 634      *
 635      * If you ask for a particular skip link to be printed, it is then your responsibility
 636      * to ensure that the appropriate <a name="..."> tag is printed in the body of the
 637      * page, so that the skip link goes somewhere.
 638      *
 639      * Even if a particular skip link is requested more than once, only one copy of it will be output.
 640      *
 641      * @param $target the name of anchor this link should go to. For example 'maincontent'.
 642      * @param $linktext The text to use for the skip link. Normally get_string('skipto', 'access', ...);
 643      */
 644     public function skip_link_to($target, $linktext) {
 645         if ($this->topofbodydone) {
 646             debugging('Page header already printed, can not add skip links any more, code needs to be fixed.');
 647             return;
 648         }
 649         $this->skiplinks[$target] = $linktext;
 650     }
 651
 652     /**
 653      * !!!DEPRECATED!!! please use js_init_call() if possible
 654      * Ensure that the specified JavaScript function is called from an inline script
 655      * somewhere on this page.
 656      *
 657      * By default the call will be put in a script tag at the
 658      * end of the page after initialising Y instance, since this gives best page-load
 659      * performance and allows you to use YUI3 library.
 660      *
 661      * If you request that a particular function is called several times, then
 662      * that is what will happen (unlike linking to a CSS or JS file, where only
 663      * one link will be output).
 664      *
 665      * The main benefit of the method is the automatic encoding of all function parameters.
 666      *
 667      * @param string $function the name of the JavaScritp function to call. Can
 668      *      be a compound name like 'Y.Event.purgeElement'. Can also be
 669      *      used to create and object by using a 'function name' like 'new user_selector'.
 670      * @param array $arguments and array of arguments to be passed to the function.
 671      *      When generating the function call, this will be escaped using json_encode,
 672      *      so passing objects and arrays should work.
 673      * @param bool $ondomready
 674      * @param int $delay
 675      * @return void
 676      */
 677     public function js_function_call($function, array $arguments = null, $ondomready = false, $delay = 0) {
 678         $where = $ondomready ? 'ondomready' : 'normal';
 679         $this->jscalls[$where][] = array($function, $arguments, $delay);
 680     }
 681
 682     /**
 683      * Adds a call to make use of a YUI gallery module. DEPRECATED DO NOT USE!!!
 684      *
 685      * @deprecated DO NOT USE
 686      *
 687      * @param string|array $modules One or more gallery modules to require
 688      * @param string $version
 689      * @param string $function
 690      * @param array $arguments
 691      * @param bool $ondomready
 692      */
 693     public function js_gallery_module($modules, $version, $function, array $arguments = null, $ondomready = false) {
 694         global $CFG;
 695         debugging('This function will be removed before 2.0 is released please change it from js_gallery_module to yui_module', DEBUG_DEVELOPER);
 696         $this->yui_module($modules, $function, $arguments, $version, $ondomready);
 697     }
 698
 699     /**
 700      * Creates a JavaScript function call that requires one or more modules to be loaded
 701      *
 702      * This function can be used to include all of the standard YUI module types within JavaScript:
 703      *     - YUI3 modules    [node, event, io]
 704      *     - YUI2 modules    [yui2-*]
 705      *     - Moodle modules  [moodle-*]
 706      *     - Gallery modules [gallery-*]
 707      *
 708      * @param array|string $modules One or more modules
 709      * @param string $function The function to call once modules have been loaded
 710      * @param array $arguments An array of arguments to pass to the function
 711      * @param string $galleryversion The gallery version to use
 712      * @param bool $ondomready
 713      */
 714     public function yui_module($modules, $function, array $arguments = null, $galleryversion = '2010.04.08-12-35', $ondomready = false) {
 715         global $CFG;
 716
 717         if (!is_array($modules)) {
 718             $modules = array($modules);
 719         }
 720         if (empty($CFG->useexternalyui) || true) {
 721             // We need to set the M.yui.galleryversion to the correct version
 722             $jscode = 'M.yui.galleryversion='.json_encode($galleryversion).';';
 723         } else {
 724             // Set Y's config.gallery to the version
 725             $jscode = 'Y.config.gallery='.json_encode($galleryversion).';';
 726         }
 727         $jscode .= 'Y.use('.join(',', array_map('json_encode', $modules)).',function() {'.js_writer::function_call($function, $arguments).'});';
 728         if ($ondomready) {
 729             $jscode = "Y.on('domready', function() { $jscode });";
 730         }
 731         $this->jsinitcode[] = $jscode;
 732     }
 733
 734     /**
 735      * Ensure that the specified JavaScript function is called from an inline script
 736      * from page footer.
 737      *
 738      * @param string $function the name of the JavaScritp function to with init code,
 739      *      usually something like 'M.mod_mymodule.init'
 740      * @param array $extraarguments and array of arguments to be passed to the function.
 741      *      The first argument is always the YUI3 Y instance with all required dependencies
 742      *      already loaded.
 743      * @param bool $ondomready wait for dom ready (helps with some IE problems when modifying DOM)
 744      * @param array $module JS module specification array
 745      * @return void
 746      */
 747     public function js_init_call($function, array $extraarguments = null, $ondomready = false, array $module = null) {
 748         $jscode = js_writer::function_call_with_Y($function, $extraarguments);
 749         if (!$module) {
 750             // detect module automatically
 751             if (preg_match('/M\.([a-z0-9]+_[^\.]+)/', $function, $matches)) {
 752                 $module = $this->find_module($matches[1]);
 753             }
 754         }
 755
 756         $this->js_init_code($jscode, $ondomready, $module);
 757     }
 758
 759     /**
 760      * Add short static javascript code fragment to page footer.
 761      * This is intended primarily for loading of js modules and initialising page layout.
 762      * Ideally the JS code fragment should be stored in plugin renderer so that themes
 763      * may override it.
 764      * @param string $jscode
 765      * @param bool $ondomready wait for dom ready (helps with some IE problems when modifying DOM)
 766      * @param array $module JS module specification array
 767      * @return void
 768      */
 769     public function js_init_code($jscode, $ondomready = false, array $module = null) {
 770         $jscode = trim($jscode, " ;\n"). ';';
 771
 772         if ($module) {
 773             $this->js_module($module);
 774             $modulename = $module['name'];
 775             $jscode = "Y.use('$modulename', function(Y) { $jscode });";
 776         }
 777
 778         if ($ondomready) {
 779             $jscode = "Y.on('domready', function() { $jscode });";
 780         }
 781
 782         $this->jsinitcode[] = $jscode;
 783     }
 784
 785     /**
 786      * Make a language string available to JavaScript.
 787      *
 788      * All the strings will be available in a M.str object in the global namespace.
 789      * So, for example, after a call to $PAGE->requires->string_for_js('course', 'moodle');
 790      * then the JavaScript variable M.str.moodle.course will be 'Course', or the
 791      * equivalent in the current language.
 792      *
 793      * The arguments to this function are just like the arguments to get_string
 794      * except that $component is not optional, and there are some aspects to consider
 795      * when the string contains {$a} placeholder.
 796      *
 797      * If the string does not contain any {$a} placeholder, you can simply use
 798      * M.str.component.identifier to obtain it. If you prefer, you can call
 799      * M.util.get_string(identifier, component) to get the same result.
 800      *
 801      * If you need to use {$a} placeholders, there are two options. Either the
 802      * placeholder should be substituted in PHP on server side or it should
 803      * be substituted in Javascript at client side.
 804      *
 805      * To substitute the placeholder at server side, just provide the required
 806      * value for the placeholder when you require the string. Because each string
 807      * is only stored once in the JavaScript (based on $identifier and $module)
 808      * you cannot get the same string with two different values of $a. If you try,
 809      * an exception will be thrown. Once the placeholder is substituted, you can
 810      * use M.str or M.util.get_string() as shown above:
 811      *
 812      *     // require the string in PHP and replace the placeholder
 813      *     $PAGE->requires->string_for_js('fullnamedisplay', 'moodle', $USER);
 814      *     // use the result of the substitution in Javascript
 815      *     alert(M.str.moodle.fullnamedisplay);
 816      *
 817      * To substitute the placeholder at client side, use M.util.get_string()
 818      * function. It implements the same logic as {@see get_string()}:
 819      *
 820      *     // require the string in PHP but keep {$a} as it is
 821      *     $PAGE->requires->string_for_js('fullnamedisplay', 'moodle');
 822      *     // provide the values on the fly in Javascript
 823      *     user = { firstname : 'Harry', lastname : 'Potter' }
 824      *     alert(M.util.get_string('fullnamedisplay', 'moodle', user);
 825      *
 826      * If you do need the same string expanded with different $a values in PHP
 827      * on server side, then the solution is to put them in your own data structure
 828      * (e.g. and array) that you pass to JavaScript with {@link data_for_js()}.
 829      *
 830      * @param string $identifier the desired string.
 831      * @param string $module the language file to look in.
 832      * @param mixed $a any extra data to add into the string (optional).
 833      */
 834     public function string_for_js($identifier, $component, $a = NULL) {
 835         $string = get_string($identifier, $component, $a);
 836         if (!$component) {
 837             throw new coding_exception('The $module parameter is required for page_requirements_manager::string_for_js.');
 838         }
 839         if (isset($this->stringsforjs[$component][$identifier]) && $this->stringsforjs[$component][$identifier] !== $string) {
 840             throw new coding_exception("Attempt to re-define already required string '$identifier' " .
 841                     "from lang file '$component'. Did you already ask for it with a different \$a? {$this->stringsforjs[$component][$identifier]} !== $string");
 842         }
 843         $this->stringsforjs[$component][$identifier] = $string;
 844     }
 845
 846     /**
 847      * Make an array of language strings available for JS
 848      *
 849      * This function calls the above function {@link string_for_js()} for each requested
 850      * string in the $identifiers array that is passed to the argument for a single module
 851      * passed in $module.
 852      *
 853      * <code>
 854      * $PAGE->requires->strings_for_js(array('one', 'two', 'three'), 'mymod', array('a', null, 3));
 855      *
 856      * // The above is identitical to calling
 857      *
 858      * $PAGE->requires->string_for_js('one', 'mymod', 'a');
 859      * $PAGE->requires->string_for_js('two', 'mymod');
 860      * $PAGE->requires->string_for_js('three', 'mymod', 3);
 861      * </code>
 862      *
 863      * @param array $identifiers An array of desired strings
 864      * @param string $component The module to load for
 865      * @param mixed $a This can either be a single variable that gets passed as extra
 866      *         information for every string or it can be an array of mixed data where the
 867      *         key for the data matches that of the identifier it is meant for.
 868      *
 869      */
 870     public function strings_for_js($identifiers, $component, $a=NULL) {
 871         foreach ($identifiers as $key => $identifier) {
 872             if (is_array($a) && array_key_exists($key, $a)) {
 873                 $extra = $a[$key];
 874             } else {
 875                 $extra = $a;
 876             }
 877             $this->string_for_js($identifier, $component, $extra);
 878         }
 879     }
 880
 881     /**
 882      * !!!!!!DEPRECATED!!!!!! please use js_init_call() for everything now.
 883      *
 884      * Make some data from PHP available to JavaScript code.
 885      *
 886      * For example, if you call
 887      * <pre>
 888      *      $PAGE->requires->data_for_js('mydata', array('name' => 'Moodle'));
 889      * </pre>
 890      * then in JavsScript mydata.name will be 'Moodle'.
 891      * @param string $variable the the name of the JavaScript variable to assign the data to.
 892      *      Will probably work if you use a compound name like 'mybuttons.button[1]', but this
 893      *      should be considered an experimental feature.
 894      * @param mixed $data The data to pass to JavaScript. This will be escaped using json_encode,
 895      *      so passing objects and arrays should work.
 896      * @param bool $inhead initialise in head
 897      * @return void
 898      */
 899     public function data_for_js($variable, $data, $inhead=false) {
 900         $where = $inhead ? 'head' : 'footer';
 901         $this->jsinitvariables[$where][] = array($variable, $data);
 902     }
 903
 904     /**
 905      * Creates a YUI event handler.
 906      *
 907      * @param mixed $selector standard YUI selector for elemnts, may be array or string, element id is in the form "#idvalue"
 908      * @param string $event A valid DOM event (click, mousedown, change etc.)
 909      * @param string $function The name of the function to call
 910      * @param array  $arguments An optional array of argument parameters to pass to the function
 911      * @return void
 912      */
 913     public function event_handler($selector, $event, $function, array $arguments = null) {
 914         $this->eventhandlers[] = array('selector'=>$selector, 'event'=>$event, 'function'=>$function, 'arguments'=>$arguments);
 915     }
 916
 917     /**
 918      * Returns code needed for registering of event handlers.
 919      * @return string JS code
 920      */
 921     protected function get_event_handler_code() {
 922         $output = '';
 923         foreach ($this->eventhandlers as $h) {
 924             $output .= js_writer::event_handler($h['selector'], $h['event'], $h['function'], $h['arguments']);
 925         }
 926         return $output;
 927     }
 928
 929     /**
 930      * Get the inline JavaScript code that need to appear in a particular place.
 931      * @return bool $ondomready
 932      */
 933     protected function get_javascript_code($ondomready) {
 934         $where = $ondomready ? 'ondomready' : 'normal';
 935         $output = '';
 936         if ($this->jscalls[$where]) {
 937             foreach ($this->jscalls[$where] as $data) {
 938                 $output .= js_writer::function_call($data[0], $data[1], $data[2]);
 939             }
 940             if (!empty($ondomready)) {
 941                 $output = "    Y.on('domready', function() {\n$output\n    });";
 942             }
 943         }
 944         return $output;
 945     }
 946
 947     /**
 948      * Returns js code to be executed when Y is available.
 949      * @return unknown_type
 950      */
 951     protected function get_javascript_init_code() {
 952         if (count($this->jsinitcode)) {
 953             return implode("\n", $this->jsinitcode) . "\n";
 954         }
 955         return '';
 956     }
 957
 958     /**
 959      * Returns basic YUI3 JS loading code.
 960      * YUI3 is using autoloading of both CSS and JS code.
 961      *
 962      * Major benefit of this compared to standard js/csss loader is much improved
 963      * caching, better browser cache utilisation, much fewer http requests.
 964      *
 965      * @return string
 966      */
 967     protected function get_yui3lib_headcode() {
 968         $code = $this->yui3loader->tags();
 969         // unfortunately yui loader does not produce xhtml strict code, so let's fix it for now
 970         $code = str_replace('&amp;', '&', $code);
 971         $code = str_replace('&', '&amp;', $code);
 972         return $code;
 973     }
 974
 975     /**
 976      * Returns basic YUI2 JS loading code.
 977      * It can be called manually at any time.
 978      * If called manually the result needs to be output using echo().
 979      *
 980      * Major benefit of this compared to standard js loader is much improved
 981      * caching, better browser cache utilisation, much fewer http requests.
 982      *
 983      * All YUI2 CSS is loaded automatically.
 984      *
 985      * @return string JS embedding code
 986      */
 987     public function get_yui2lib_code() {
 988         global $CFG;
 989
 990         if ($this->headdone) {
 991             $code = $this->yui2loader->script();
 992         } else {
 993             $code = $this->yui2loader->script();
 994             if ($this->yui2loader->combine) {
 995                 $skinurl = $this->yui2loader->comboBase . $CFG->yui2version . '/build/assets/skins/sam/skin.css';
 996             } else {
 997                 $skinurl = $this->yui2loader->base . 'assets/skins/sam/skin.css';
 998             }
 999             // please note this is a temporary hack until we fully migrate to later YUI3 that has all the widgets
1000             $attributes = array('rel'=>'stylesheet', 'type'=>'text/css', 'href'=>$skinurl);
1001             $code .= "\n" . html_writer::empty_tag('link', $attributes) . "\n";
1002         }
1003         $code = str_replace('&amp;', '&', $code);
1004         $code = str_replace('&', '&amp;', $code);
1005         return $code;
1006     }
1007
1008     /**
1009      * Returns html tags needed for inclusion of theme CSS
1010      * @return string
1011      */
1012     protected function get_css_code() {
1013         // First of all the theme CSS, then any custom CSS
1014         // Please note custom CSS is strongly discouraged,
1015         // because it can not be overridden by themes!
1016         // It is suitable only for things like mod/data which accepts CSS from teachers.
1017         $attributes = array('rel'=>'stylesheet', 'type'=>'text/css');
1018
1019         // This line of code may look funny but it is currently required in order
1020         // to avoid MASSIVE display issues in Internet Explorer.
1021         // As of IE8 + YUI3.1.1 the reference stylesheet (firstthemesheet) gets
1022         // ignored whenever another resource is added until such time as a redraw
1023         // is forced, usually by moving the mouse over the affected element.
1024         $code = html_writer::tag('script', '/** Required in order to fix style inclusion problems in IE with YUI **/', array('id'=>'firstthemesheet', 'type'=>'text/css'));
1025
1026         $urls = $this->cssthemeurls + $this->cssurls;
1027         foreach ($urls as $url) {
1028             $attributes['href'] = $url;
1029             $code .= html_writer::empty_tag('link', $attributes) . "\n";
1030             // this id is needed in first sheet only so that theme may override YUI sheets laoded on the fly
1031             unset($attributes['id']);
1032         }
1033
1034         return $code;
1035     }
1036
1037     /**
1038      * Adds extra modules specified after printing of page header
1039      */
1040     protected function get_extra_modules_code() {
1041         if (empty($this->extramodules)) {
1042             return '';
1043         }
1044         return html_writer::script(js_writer::function_call('M.yui.add_module', array($this->extramodules)));
1045     }
1046
1047     /**
1048      * Generate any HTML that needs to go inside the <head> tag.
1049      *
1050      * Normally, this method is called automatically by the code that prints the
1051      * <head> tag. You should not normally need to call it in your own code.
1052      *
1053      * @return string the HTML code to to inside the <head> tag.
1054      */
1055     public function get_head_code(moodle_page $page, core_renderer $renderer) {
1056         global $CFG;
1057
1058         // note: the $page and $output are not stored here because it would
1059         // create circular references in memory which prevents garbage collection
1060         $this->init_requirements_data($page, $renderer);
1061
1062         // yui3 JS and CSS is always loaded first - it is cached in browser
1063         $output = $this->get_yui3lib_headcode();
1064
1065         // BC: load basic YUI2 for now, all yui2 things should be loaded via Y.use('yui2-oldmodulename')
1066         $output .= $this->get_yui2lib_code();
1067
1068         // now theme CSS + custom CSS in this specific order
1069         $output .= $this->get_css_code();
1070
1071         // set up global YUI3 loader object - this should contain all code needed by plugins
1072         // note: in JavaScript just use "YUI(M.yui.loader).use('overlay', function(Y) { .... });"
1073         // this needs to be done before including any other script
1074         $js = "var M = {}; M.yui = {}; var moodleConfigFn = function(me) {var p = me.path, b = me.name.replace(/^moodle-/,'').split('-', 3), n = b.pop();if (/(skin|core)/.test(n)) {n = b.pop();me.type = 'css';};me.path = b.join('-')+'/'+n+'/'+n+'.'+me.type;}; var galleryConfigFn = function(me) {var p = me.path,v=M.yui.galleryversion,f;if(/-(skin|core)/.test(me.name)) {me.type = 'css';p = p.replace(/-(skin|core)/, '').replace(/\.js/, '.css').split('/'), f = p.pop().replace(/(\-(min|debug))/, '');if (/-skin/.test(me.name)) {p.splice(p.length,0,v,'assets','skins','sam', f);} else {p.splice(p.length,0,v,'assets', f);};} else {p = p.split('/'), f = p.pop();p.splice(p.length,0,v, f);};me.path = p.join('/');};\n";
1075         $js .= js_writer::set_variable('M.yui.loader', $this->M_yui_loader, false) . "\n";
1076         $js .= js_writer::set_variable('M.cfg', $this->M_cfg, false);
1077         $js = str_replace('"@GALLERYCONFIGFN@"', 'galleryConfigFn', $js);
1078         $js = str_replace('"@MOODLECONFIGFN@"', 'moodleConfigFn', $js);
1079
1080         $output .= html_writer::script($js);
1081
1082         // link our main JS file, all core stuff should be there
1083         $output .= html_writer::script('', $this->js_fix_url('/lib/javascript-static.js'));
1084
1085         // add variables
1086         if ($this->jsinitvariables['head']) {
1087             $js = '';
1088             foreach ($this->jsinitvariables['head'] as $data) {
1089                 list($var, $value) = $data;
1090                 $js .= js_writer::set_variable($var, $value, true);
1091             }
1092             $output .= html_writer::script($js);
1093         }
1094
1095         // all the other linked things from HEAD - there should be as few as possible
1096         if ($this->jsincludes['head']) {
1097             foreach ($this->jsincludes['head'] as $url) {
1098                 $output .= html_writer::script('', $url);
1099             }
1100         }
1101
1102         // mark head sending done, it is not possible to anything there
1103         $this->headdone = true;
1104
1105         return $output;
1106     }
1107
1108     /**
1109      * Generate any HTML that needs to go at the start of the <body> tag.
1110      *
1111      * Normally, this method is called automatically by the code that prints the
1112      * <head> tag. You should not normally need to call it in your own code.
1113      *
1114      * @return string the HTML code to go at the start of the <body> tag.
1115      */
1116     public function get_top_of_body_code() {
1117         // first the skip links
1118         $links = '';
1119         $attributes = array('class'=>'skip');
1120         foreach ($this->skiplinks as $url => $text) {
1121             $attributes['href'] = '#' . $url;
1122             $links .= html_writer::tag('a', $text, $attributes);
1123         }
1124         $output = html_writer::tag('div', $links, array('class'=>'skiplinks')) . "\n";
1125
1126         // then the clever trick for hiding of things not needed when JS works
1127         $output .= html_writer::script("document.body.className += ' jsenabled';") . "\n";
1128         $this->topofbodydone = true;
1129         return $output;
1130     }
1131
1132     /**
1133      * Generate any HTML that needs to go at the end of the page.
1134      *
1135      * Normally, this method is called automatically by the code that prints the
1136      * page footer. You should not normally need to call it in your own code.
1137      *
1138      * @return string the HTML code to to at the end of the page.
1139      */
1140     public function get_end_code() {
1141         global $CFG;
1142         // add other requested modules
1143         $output = $this->get_extra_modules_code();
1144
1145         // add missing YUI2 YUI - to be removed once we convert everything to YUI3!
1146         $output .= $this->get_yui2lib_code();
1147
1148         // all the other linked scripts - there should be as few as possible
1149         if ($this->jsincludes['footer']) {
1150             foreach ($this->jsincludes['footer'] as $url) {
1151                 $output .= html_writer::script('', $url);
1152             }
1153         }
1154
1155         // add all needed strings
1156         if (!empty($this->stringsforjs)) {
1157             $output .= html_writer::script(js_writer::set_variable('M.str', $this->stringsforjs));
1158         }
1159
1160         // add variables
1161         if ($this->jsinitvariables['footer']) {
1162             $js = '';
1163             foreach ($this->jsinitvariables['footer'] as $data) {
1164                 list($var, $value) = $data;
1165                 $js .= js_writer::set_variable($var, $value, true);
1166             }
1167             $output .= html_writer::script($js);
1168         }
1169
1170         $inyuijs = $this->get_javascript_code(false);
1171         $ondomreadyjs = $this->get_javascript_code(true);
1172         $jsinit = $this->get_javascript_init_code();
1173         $handlersjs = $this->get_event_handler_code();
1174
1175         // there is no global Y, make sure it is available in your scope
1176         $js = "YUI(M.yui.loader).use('node', function(Y) {\n{$inyuijs}{$ondomreadyjs}{$jsinit}{$handlersjs}\n});";
1177
1178         $output .= html_writer::script($js);
1179
1180         return $output;
1181     }
1182
1183     /**
1184      * @return boolean Have we already output the code in the <head> tag?
1185      */
1186     public function is_head_done() {
1187         return $this->headdone;
1188     }
1189
1190     /**
1191      * @return boolean Have we already output the code at the start of the <body> tag?
1192      */
1193     public function is_top_of_body_done() {
1194         return $this->topofbodydone;
1195     }
1196 }
1197
1198 /**
1199  * Invalidate all server and client side JS caches.
1200  * @return void
1201  */
1202 function js_reset_all_caches() {
1203     global $CFG;
1204     require_once("$CFG->libdir/filelib.php");
1205
1206     set_config('jsrev', empty($CFG->jsrev) ? 1 : $CFG->jsrev+1);
1207     fulldelete("$CFG->dataroot/cache/js");
1208 }
1209