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 loader information 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 stdClass();
 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             $this->yui2loader->allowRollups = false;
 131         } else {
 132             $this->yui3loader->filter = null;
 133             $this->yui2loader->filter = null;
 134         }
 135         if (!empty($CFG->useexternalyui) and strpos($CFG->httpswwwroot, 'https:') !== 0) {
 136             $this->yui3loader->base = 'http://yui.yahooapis.com/' . $CFG->yui3version . '/build/';
 137             $this->yui2loader->base = 'http://yui.yahooapis.com/' . $CFG->yui2version . '/build/';
 138             $this->yui3loader->comboBase = 'http://yui.yahooapis.com/combo?';
 139             $this->yui2loader->comboBase = 'http://yui.yahooapis.com/combo?';
 140         } else {
 141             $this->yui3loader->base = $CFG->httpswwwroot . '/lib/yui/'. $CFG->yui3version . '/build/';
 142             $this->yui2loader->base = $CFG->httpswwwroot . '/lib/yui/'. $CFG->yui2version . '/build/';
 143             $this->yui3loader->comboBase = $CFG->httpswwwroot . '/theme/yui_combo.php?';
 144             $this->yui2loader->comboBase = $CFG->httpswwwroot . '/theme/yui_combo.php?';
 145         }
 146
 147         // enable combo loader? this significantly helps with caching and performance!
 148         $this->yui3loader->combine = !empty($CFG->yuicomboloading);
 149         $this->yui2loader->combine = !empty($CFG->yuicomboloading);
 150
 151         if (empty($CFG->cachejs)) {
 152             $jsrev = -1;
 153         } else if (empty($CFG->jsrev)) {
 154             $jsrev = 1;
 155         } else {
 156             $jsrev = $CFG->jsrev;
 157         }
 158
 159         // set up JS YUI loader helper object
 160         $this->M_yui_loader = new stdClass();
 161         $this->M_yui_loader->base         = $this->yui3loader->base;
 162         $this->M_yui_loader->comboBase    = $this->yui3loader->comboBase;
 163         $this->M_yui_loader->combine      = $this->yui3loader->combine;
 164         $this->M_yui_loader->filter       = (string)$this->yui3loader->filter;
 165         $this->M_yui_loader->insertBefore = 'firstthemesheet';
 166         $this->M_yui_loader->modules      = array();
 167         $this->M_yui_loader->groups       = array(
 168             'moodle' => array(
 169                 'name' => 'moodle',
 170                 'base' => $CFG->httpswwwroot . '/theme/yui_combo.php?moodle/'.$jsrev.'/',
 171                 'comboBase' => $CFG->httpswwwroot . '/theme/yui_combo.php?',
 172                 'combine' => $this->yui3loader->combine,
 173                 'filter' => '',
 174                 'ext' => false,
 175                 'root' => 'moodle/'.$jsrev.'/', // Add the rev to the root path so that we can control caching
 176                 'patterns' => array(
 177                     'moodle-' => array(
 178                         'group' => 'moodle',
 179                         'configFn' => '@MOODLECONFIGFN@'
 180                     ),
 181                     'root' => 'moodle'
 182                 )
 183             ),
 184             'local' => array(
 185                 'name' => 'gallery',
 186                 'base' => $CFG->wwwroot.'/lib/yui/gallery/',
 187                 'comboBase' => $CFG->httpswwwroot . '/theme/yui_combo.php?',
 188                 'combine' => $this->yui3loader->combine,
 189                 'filter' => $this->M_yui_loader->filter,
 190                 'ext' => false,
 191                 'root' => 'gallery/',
 192                 'patterns' => array(
 193                     'gallery-' => array(
 194                         'group' => 'gallery',
 195                         'configFn' => '@GALLERYCONFIGFN@',
 196                     ),
 197                     'root' => 'gallery'
 198                 )
 199             )
 200         );
 201         $this->add_yui2_modules(); // adds loading info for all YUI2 modules
 202         $this->js_module($this->find_module('core_filepicker'));
 203         $this->js_module($this->find_module('core_dock'));
 204
 205     }
 206
 207     /**
 208      * This method adds yui2 modules into the yui3 JS loader-
 209      * @return void
 210      */
 211     protected function add_yui2_modules() {
 212         //note: this function is definitely not perfect, because
 213         //      it adds tons of markup into each page, but it can be
 214         //      abstracted into separate JS file with proper headers
 215         global $CFG;
 216
 217         $GLOBALS['yui_current'] = array();
 218         require($CFG->libdir.'/yui/phploader/lib/meta/config_'.$CFG->yui2version.'.php');
 219         $info = $GLOBALS['yui_current'];
 220         unset($GLOBALS['yui_current']);
 221
 222         if (empty($CFG->yuicomboloading)) {
 223             $urlbase = $this->yui2loader->base;
 224         } else {
 225             $urlbase = $this->yui2loader->comboBase.$CFG->yui2version.'/build/';
 226         }
 227
 228         $modules = array();
 229         $ignored = array(); // list of CSS modules that are not needed
 230         foreach ($info['moduleInfo'] as $name => $module) {
 231             if ($module['type'] === 'css') {
 232                 $ignored[$name] = true;
 233             } else {
 234                 $modules['yui2-'.$name] = $module;
 235             }
 236         }
 237         foreach ($modules as $name=>$module) {
 238             $module['fullpath'] = $urlbase.$module['path']; // fix path to point to correct location
 239             unset($module['path']);
 240             unset($module['skinnable']); // we load all YUI2 css automatically, this prevents weird missing css loader problems
 241             foreach(array('requires', 'optional', 'supersedes') as $fixme) {
 242                 if (!empty($module[$fixme])) {
 243                     $fixed = false;
 244                     foreach ($module[$fixme] as $key=>$dep) {
 245                         if (isset($ignored[$dep])) {
 246                             unset($module[$fixme][$key]);
 247                             $fixed = true;
 248                         } else {
 249                             $module[$fixme][$key] = 'yui2-'.$dep;
 250                         }
 251                     }
 252                     if ($fixed) {
 253                         $module[$fixme] = array_merge($module[$fixme]); // fix keys
 254                     }
 255                 }
 256             }
 257             $this->M_yui_loader->modules[$name] = $module;
 258             if (debugging('', DEBUG_DEVELOPER)) {
 259                 if (!array_key_exists($name, $this->debug_moduleloadstacktraces)) {
 260                     $this->debug_moduleloadstacktraces[$name] = array();
 261                 }
 262                 $this->debug_moduleloadstacktraces[$name][] = format_backtrace(debug_backtrace());
 263             }
 264         }
 265     }
 266
 267     /**
 268      * Initialise with the bits of JavaScript that every Moodle page should have.
 269      *
 270      * @param moodle_page $page
 271      * @param core_renderer $renderer
 272      */
 273     protected function init_requirements_data(moodle_page $page, core_renderer $renderer) {
 274         global $CFG;
 275
 276         // JavaScript should always work with $CFG->httpswwwroot rather than $CFG->wwwroot.
 277         // Otherwise, in some situations, users will get warnings about insecure content
 278         // on secure pages from their web browser.
 279
 280         $this->M_cfg = array(
 281             'wwwroot'             => $CFG->httpswwwroot, // Yes, really. See above.
 282             'sesskey'             => sesskey(),
 283             'loadingicon'         => $renderer->pix_url('i/loading_small', 'moodle')->out(false),
 284             'themerev'            => theme_get_revision(),
 285             'theme'               => $page->theme->name,
 286             'jsrev'               => ((empty($CFG->cachejs) or empty($CFG->jsrev)) ? -1 : $CFG->jsrev),
 287         );
 288         if (debugging('', DEBUG_DEVELOPER)) {
 289             $this->M_cfg['developerdebug'] = true;
 290             $this->yui2_lib('logger');
 291         }
 292
 293         // accessibility stuff
 294         $this->skip_link_to('maincontent', get_string('tocontent', 'access'));
 295
 296         // to be removed soon
 297         $this->yui2_lib('dom');        // at least javascript-static.js needs to be migrated to YUI3
 298
 299         $this->string_for_js('confirmation', 'admin');
 300         $this->string_for_js('cancel', 'moodle');
 301         $this->string_for_js('yes', 'moodle');
 302
 303         if ($page->pagelayout === 'frametop') {
 304             $this->js_init_call('M.util.init_frametop');
 305         }
 306     }
 307
 308     /**
 309      * Ensure that the specified JavaScript file is linked to from this page.
 310      *
 311      * NOTE: This function is to be used in rare cases only, please store your JS in module.js file
 312      * and use $PAGE->requires->js_init_call() instead.
 313      *
 314      * By default the link is put at the end of the page, since this gives best page-load performance.
 315      *
 316      * Even if a particular script is requested more than once, it will only be linked
 317      * to once.
 318      *
 319      * @param string|moodle_url $url The path to the .js file, relative to $CFG->dirroot / $CFG->wwwroot.
 320      *      For example '/mod/mymod/customscripts.js'; use moodle_url for external scripts
 321      * @param bool $inhead initialise in head
 322      * @return void
 323      */
 324     public function js($url, $inhead=false) {
 325         $url = $this->js_fix_url($url);
 326         $where = $inhead ? 'head' : 'footer';
 327         $this->jsincludes[$where][$url->out()] = $url;
 328     }
 329
 330     /**
 331      * Ensure that the specified YUI2 library file, and all its required dependencies,
 332      * are linked to from this page.
 333      *
 334      * By default the link is put at the end of the page, since this gives best page-load
 335      * performance. Optional dependencies are not loaded automatically - if you want
 336      * them you will need to load them first with other calls to this method.
 337      *
 338      * Even if a particular library is requested more than once (perhaps as a dependency
 339      * of other libraries) it will only be linked to once.
 340      *
 341      * The library is leaded as soon as possible, if $OUTPUT->header() not used yet it
 342      * is put into the page header, otherwise it is loaded in the page footer.
 343      *
 344      * @param string|array $libname the name of the YUI2 library you require. For example 'autocomplete'.
 345      * @return void
 346      */
 347     public function yui2_lib($libname) {
 348         $libnames = (array)$libname;
 349         foreach ($libnames as $lib) {
 350             $this->yui2loader->load($lib);
 351         }
 352     }
 353
 354     /**
 355      * Returns the actual url through which a script is served.
 356      * @param moodle_url|string $url full moodle url, or shortened path to script
 357      * @return moodle_url
 358      */
 359     protected function js_fix_url($url) {
 360         global $CFG;
 361
 362         if ($url instanceof moodle_url) {
 363             return $url;
 364         } else if (strpos($url, '/') === 0) {
 365             if (debugging()) {
 366                 // check file existence only when in debug mode
 367                 if (!file_exists($CFG->dirroot . strtok($url, '?'))) {
 368                     throw new coding_exception('Attempt to require a JavaScript file that does not exist.', $url);
 369                 }
 370             }
 371             if (!empty($CFG->cachejs) and !empty($CFG->jsrev) and strpos($url, '/lib/editor/') !== 0 and substr($url, -3) === '.js') {
 372                 return new moodle_url($CFG->httpswwwroot.'/lib/javascript.php', array('file'=>$url, 'rev'=>$CFG->jsrev));
 373             } else {
 374                 return new moodle_url($CFG->httpswwwroot.$url);
 375             }
 376         } else {
 377             throw new coding_exception('Invalid JS url, it has to be shortened url starting with / or moodle_url instance.', $url);
 378         }
 379     }
 380
 381     /**
 382      * Find out if JS module present and return details.
 383      * @param string $component name of component in frankenstyle, ex: core_group, mod_forum
 384      * @return array description of module or null if not found
 385      */
 386     protected function find_module($component) {
 387         global $CFG;
 388
 389         $module = null;
 390
 391
 392         if (strpos($component, 'core_') === 0) {
 393             // must be some core stuff - list here is not complete, this is just the stuff used from multiple places
 394             // so that we do nto have to repeat the definition of these modules over and over again
 395             switch($component) {
 396                 case 'core_filepicker':
 397                     $module = array('name'     => 'core_filepicker',
 398                                     'fullpath' => '/repository/filepicker.js',
 399                                     'requires' => array('base', 'node', 'node-event-simulate', 'json', 'async-queue', 'io-base', 'io-upload-iframe', 'io-form', 'yui2-button', 'yui2-container', 'yui2-layout', 'yui2-menu', 'yui2-treeview', 'yui2-dragdrop', 'yui2-cookie'),
 400                                     'strings'  => array(array('add', 'repository'), array('back', 'repository'), array('cancel', 'moodle'), array('close', 'repository'),
 401                                                         array('cleancache', 'repository'), array('copying', 'repository'), array('date', 'repository'), array('downloadsucc', 'repository'),
 402                                                         array('emptylist', 'repository'), array('error', 'repository'), array('federatedsearch', 'repository'),
 403                                                         array('filenotnull', 'repository'), array('getfile', 'repository'), array('help', 'moodle'), array('iconview', 'repository'),
 404                                                         array('invalidjson', 'repository'), array('linkexternal', 'repository'), array('listview', 'repository'),
 405                                                         array('loading', 'repository'), array('login', 'repository'), array('logout', 'repository'), array('noenter', 'repository'),
 406                                                         array('noresult', 'repository'), array('manageurl', 'repository'), array('popup', 'repository'), array('preview', 'repository'),
 407                                                         array('refresh', 'repository'), array('save', 'repository'), array('saveas', 'repository'), array('saved', 'repository'),
 408                                                         array('saving', 'repository'), array('search', 'repository'), array('searching', 'repository'), array('size', 'repository'),
 409                                                         array('submit', 'repository'), array('sync', 'repository'), array('title', 'repository'), array('upload', 'repository'),
 410                                                         array('uploading', 'repository'), array('xhtmlerror', 'repository'),
 411                                                         array('cancel'), array('chooselicense', 'repository'), array('author', 'repository'),
 412                                                         array('ok', 'moodle'), array('error', 'moodle'), array('info', 'moodle'), array('norepositoriesavailable', 'repository'), array('norepositoriesexternalavailable', 'repository'),
 413                                                         array('nofilesattached', 'repository'), array('filepicker', 'repository'),
 414                                                         array('nofilesavailable', 'repository'), array('overwrite', 'repository'),
 415                                                         array('renameto', 'repository'), array('fileexists', 'repository'),
 416                                                         array('fileexistsdialogheader', 'repository'), array('fileexistsdialog_editor', 'repository'),
 417                                                         array('fileexistsdialog_filemanager', 'repository')
 418                                                     ));
 419                     break;
 420                 case 'core_comment':
 421                     $module = array('name'     => 'core_comment',
 422                                     'fullpath' => '/comment/comment.js',
 423                                     'requires' => array('base', 'io-base', 'node', 'json', 'yui2-animation', 'overlay'),
 424                                     'strings' => array(array('confirmdeletecomments', 'admin'), array('yes', 'moodle'), array('no', 'moodle'))
 425                                 );
 426                     break;
 427                 case 'core_role':
 428                     $module = array('name'     => 'core_role',
 429                                     'fullpath' => '/admin/roles/module.js',
 430                                     'requires' => array('node', 'cookie'));
 431                     break;
 432                 case 'core_completion':
 433                     $module = array('name'     => 'core_completion',
 434                                     'fullpath' => '/course/completion.js');
 435                     break;
 436                 case 'core_dock':
 437                     $module = array('name'     => 'core_dock',
 438                                     'fullpath' => '/blocks/dock.js',
 439                                     'requires' => array('base', 'node', 'event-custom', 'event-mouseenter', 'event-resize'),
 440                                     'strings' => array(array('addtodock', 'block'),array('undockitem', 'block'),array('undockall', 'block'),array('thisdirectionvertical', 'langconfig')));
 441                     break;
 442                 case 'core_message':
 443                     $module = array('name'     => 'core_message',
 444                                     'requires' => array('base', 'node', 'event', 'node-event-simulate'),
 445                                     'fullpath' => '/message/module.js');
 446                     break;
 447                 case 'core_group':
 448                     $module = array('name'     => 'core_group',
 449                                     'fullpath' => '/group/module.js',
 450                                     'requires' => array('node', 'overlay', 'event-mouseenter'));
 451                     break;
 452                 case 'core_question_engine':
 453                     $module = array('name'     => 'core_question_engine',
 454                                     'fullpath' => '/question/qengine.js',
 455                                     'requires' => array('node', 'event'));
 456                     break;
 457                 case 'core_rating':
 458                     $module = array('name'     => 'core_rating',
 459                                     'fullpath' => '/rating/module.js',
 460                                     'requires' => array('node', 'event', 'overlay', 'io-base', 'json'));
 461                     break;
 462                 case 'core_filetree':
 463                     $module = array('name'     => 'core_filetree',
 464                                     'fullpath' => '/files/module.js',
 465                                     'requires' => array('node', 'event', 'overlay', 'io-base', 'json', 'yui2-treeview'));
 466                     break;
 467             }
 468
 469         } else {
 470             if ($dir = get_component_directory($component)) {
 471                 if (file_exists("$dir/module.js")) {
 472                     if (strpos($dir, $CFG->dirroot.'/') === 0) {
 473                         $dir = substr($dir, strlen($CFG->dirroot));
 474                         $module = array('name'=>$component, 'fullpath'=>"$dir/module.js", 'requires' => array());
 475                     }
 476                 }
 477             }
 478         }
 479
 480         return $module;
 481     }
 482
 483     /**
 484      * Append YUI3 module to default YUI3 JS loader.
 485      * The structure of module array is described at http://developer.yahoo.com/yui/3/yui/:
 486      * @param string|array $module name of module (details are autodetected), or full module specification as array
 487      * @return void
 488      */
 489     public function js_module($module) {
 490         global $CFG;
 491
 492         if (empty($module)) {
 493             throw new coding_exception('Missing YUI3 module name or full description.');
 494         }
 495
 496         if (is_string($module)) {
 497             $module = $this->find_module($module);
 498         }
 499
 500         if (empty($module) or empty($module['name']) or empty($module['fullpath'])) {
 501             throw new coding_exception('Missing YUI3 module details.');
 502         }
 503
 504         // Don't load this module if we already have, no need to!
 505         if ($this->js_module_loaded($module['name'])) {
 506             if (debugging('', DEBUG_DEVELOPER)) {
 507                 $this->debug_moduleloadstacktraces[$module['name']][] = format_backtrace(debug_backtrace());
 508             }
 509             return;
 510         }
 511
 512         $module['fullpath'] = $this->js_fix_url($module['fullpath'])->out(false);
 513         // add all needed strings
 514         if (!empty($module['strings'])) {
 515             foreach ($module['strings'] as $string) {
 516                 $identifier = $string[0];
 517                 $component = isset($string[1]) ? $string[1] : 'moodle';
 518                 $a = isset($string[2]) ? $string[2] : null;
 519                 $this->string_for_js($identifier, $component, $a);
 520             }
 521         }
 522         unset($module['strings']);
 523
 524         // Process module requirements and attempt to load each. This allows
 525         // moodle modules to require each other.
 526         if (!empty($module['requires'])){
 527             foreach ($module['requires'] as $requirement) {
 528                 $rmodule = $this->find_module($requirement);
 529                 if (is_array($rmodule)) {
 530                     $this->js_module($rmodule);
 531                 }
 532             }
 533         }
 534
 535         if ($this->headdone) {
 536             $this->extramodules[$module['name']] = $module;
 537         } else {
 538             $this->M_yui_loader->modules[$module['name']] = $module;
 539         }
 540         if (debugging('', DEBUG_DEVELOPER)) {
 541             if (!array_key_exists($module['name'], $this->debug_moduleloadstacktraces)) {
 542                 $this->debug_moduleloadstacktraces[$module['name']] = array();
 543             }
 544             $this->debug_moduleloadstacktraces[$module['name']][] = format_backtrace(debug_backtrace());
 545         }
 546     }
 547
 548     /**
 549      * Returns true if the module has already been loaded.
 550      *
 551      * @param string|array $module
 552      * @return bool True if the module has already been loaded
 553      */
 554     protected function js_module_loaded($module) {
 555         if (is_string($module)) {
 556             $modulename = $module;
 557         } else {
 558             $modulename = $module['name'];
 559         }
 560         return array_key_exists($modulename, $this->M_yui_loader->modules) ||
 561                array_key_exists($modulename, $this->extramodules);
 562     }
 563
 564     /**
 565      * Returns the stacktraces from loading js modules.
 566      * @return array
 567      */
 568     public function get_loaded_modules() {
 569         return $this->debug_moduleloadstacktraces;
 570     }
 571
 572     /**
 573      * Ensure that the specified CSS file is linked to from this page.
 574      *
 575      * Because stylesheet links must go in the <head> part of the HTML, you must call
 576      * this function before {@link get_head_code()} is called. That normally means before
 577      * the call to print_header. If you call it when it is too late, an exception
 578      * will be thrown.
 579      *
 580      * Even if a particular style sheet is requested more than once, it will only
 581      * be linked to once.
 582      *
 583      * Please note use of this feature is strongly discouraged,
 584      * it is suitable only for places where CSS is submitted directly by teachers.
 585      * (Students must not be allowed to submit any external CSS because it may
 586      * contain embedded javascript!). Example of correct use is mod/data.
 587      *
 588      * @param string $stylesheet The path to the .css file, relative to $CFG->wwwroot.
 589      *   For example:
 590      *      $PAGE->requires->css('mod/data/css.php?d='.$data->id);
 591      */
 592     public function css($stylesheet) {
 593         global $CFG;
 594
 595         if ($this->headdone) {
 596             throw new coding_exception('Cannot require a CSS file after &lt;head> has been printed.', $stylesheet);
 597         }
 598
 599         if ($stylesheet instanceof moodle_url) {
 600             // ok
 601         } else if (strpos($stylesheet, '/') === 0) {
 602             $stylesheet = new moodle_url($CFG->httpswwwroot.$stylesheet);
 603         } else {
 604             throw new coding_exception('Invalid stylesheet parameter.', $stylesheet);
 605         }
 606
 607         $this->cssurls[$stylesheet->out()] = $stylesheet; // overrides
 608     }
 609
 610     /**
 611      * Add theme stylkesheet to page - do not use from plugin code,
 612      * this should be called only from the core renderer!
 613      * @param moodle_url $stylesheet
 614      * @return void
 615      */
 616     public function css_theme(moodle_url $stylesheet) {
 617         $this->cssthemeurls[] = $stylesheet;
 618     }
 619
 620     /**
 621      * Ensure that a skip link to a given target is printed at the top of the <body>.
 622      *
 623      * You must call this function before {@link get_top_of_body_code()}, (if not, an exception
 624      * will be thrown). That normally means you must call this before the call to print_header.
 625      *
 626      * If you ask for a particular skip link to be printed, it is then your responsibility
 627      * to ensure that the appropriate <a name="..."> tag is printed in the body of the
 628      * page, so that the skip link goes somewhere.
 629      *
 630      * Even if a particular skip link is requested more than once, only one copy of it will be output.
 631      *
 632      * @param $target the name of anchor this link should go to. For example 'maincontent'.
 633      * @param $linktext The text to use for the skip link. Normally get_string('skipto', 'access', ...);
 634      */
 635     public function skip_link_to($target, $linktext) {
 636         if ($this->topofbodydone) {
 637             debugging('Page header already printed, can not add skip links any more, code needs to be fixed.');
 638             return;
 639         }
 640         $this->skiplinks[$target] = $linktext;
 641     }
 642
 643     /**
 644      * !!!DEPRECATED!!! please use js_init_call() if possible
 645      * Ensure that the specified JavaScript function is called from an inline script
 646      * somewhere on this page.
 647      *
 648      * By default the call will be put in a script tag at the
 649      * end of the page after initialising Y instance, since this gives best page-load
 650      * performance and allows you to use YUI3 library.
 651      *
 652      * If you request that a particular function is called several times, then
 653      * that is what will happen (unlike linking to a CSS or JS file, where only
 654      * one link will be output).
 655      *
 656      * The main benefit of the method is the automatic encoding of all function parameters.
 657      *
 658      * @param string $function the name of the JavaScritp function to call. Can
 659      *      be a compound name like 'Y.Event.purgeElement'. Can also be
 660      *      used to create and object by using a 'function name' like 'new user_selector'.
 661      * @param array $arguments and array of arguments to be passed to the function.
 662      *      When generating the function call, this will be escaped using json_encode,
 663      *      so passing objects and arrays should work.
 664      * @param bool $ondomready
 665      * @param int $delay
 666      * @return void
 667      */
 668     public function js_function_call($function, array $arguments = null, $ondomready = false, $delay = 0) {
 669         $where = $ondomready ? 'ondomready' : 'normal';
 670         $this->jscalls[$where][] = array($function, $arguments, $delay);
 671     }
 672
 673     /**
 674      * Adds a call to make use of a YUI gallery module. DEPRECATED DO NOT USE!!!
 675      *
 676      * @deprecated DO NOT USE
 677      *
 678      * @param string|array $modules One or more gallery modules to require
 679      * @param string $version
 680      * @param string $function
 681      * @param array $arguments
 682      * @param bool $ondomready
 683      */
 684     public function js_gallery_module($modules, $version, $function, array $arguments = null, $ondomready = false) {
 685         global $CFG;
 686         debugging('This function will be removed before 2.0 is released please change it from js_gallery_module to yui_module', DEBUG_DEVELOPER);
 687         $this->yui_module($modules, $function, $arguments, $version, $ondomready);
 688     }
 689
 690     /**
 691      * Creates a JavaScript function call that requires one or more modules to be loaded
 692      *
 693      * This function can be used to include all of the standard YUI module types within JavaScript:
 694      *     - YUI3 modules    [node, event, io]
 695      *     - YUI2 modules    [yui2-*]
 696      *     - Moodle modules  [moodle-*]
 697      *     - Gallery modules [gallery-*]
 698      *
 699      * @param array|string $modules One or more modules
 700      * @param string $function The function to call once modules have been loaded
 701      * @param array $arguments An array of arguments to pass to the function
 702      * @param string $galleryversion The gallery version to use
 703      * @param bool $ondomready
 704      */
 705     public function yui_module($modules, $function, array $arguments = null, $galleryversion = '2010.04.08-12-35', $ondomready = false) {
 706         global $CFG;
 707
 708         if (!is_array($modules)) {
 709             $modules = array($modules);
 710         }
 711         if (empty($CFG->useexternalyui) || true) {
 712             // We need to set the M.yui.galleryversion to the correct version
 713             $jscode = 'M.yui.galleryversion='.json_encode($galleryversion).';';
 714         } else {
 715             // Set Y's config.gallery to the version
 716             $jscode = 'Y.config.gallery='.json_encode($galleryversion).';';
 717         }
 718         $jscode .= 'Y.use('.join(',', array_map('json_encode', $modules)).',function() {'.js_writer::function_call($function, $arguments).'});';
 719         if ($ondomready) {
 720             $jscode = "Y.on('domready', function() { $jscode });";
 721         }
 722         $this->jsinitcode[] = $jscode;
 723     }
 724
 725     /**
 726      * Ensure that the specified JavaScript function is called from an inline script
 727      * from page footer.
 728      *
 729      * @param string $function the name of the JavaScritp function to with init code,
 730      *      usually something like 'M.mod_mymodule.init'
 731      * @param array $extraarguments and array of arguments to be passed to the function.
 732      *      The first argument is always the YUI3 Y instance with all required dependencies
 733      *      already loaded.
 734      * @param bool $ondomready wait for dom ready (helps with some IE problems when modifying DOM)
 735      * @param array $module JS module specification array
 736      * @return void
 737      */
 738     public function js_init_call($function, array $extraarguments = null, $ondomready = false, array $module = null) {
 739         $jscode = js_writer::function_call_with_Y($function, $extraarguments);
 740         if (!$module) {
 741             // detect module automatically
 742             if (preg_match('/M\.([a-z0-9]+_[^\.]+)/', $function, $matches)) {
 743                 $module = $this->find_module($matches[1]);
 744             }
 745         }
 746
 747         $this->js_init_code($jscode, $ondomready, $module);
 748     }
 749
 750     /**
 751      * Add short static javascript code fragment to page footer.
 752      * This is intended primarily for loading of js modules and initialising page layout.
 753      * Ideally the JS code fragment should be stored in plugin renderer so that themes
 754      * may override it.
 755      * @param string $jscode
 756      * @param bool $ondomready wait for dom ready (helps with some IE problems when modifying DOM)
 757      * @param array $module JS module specification array
 758      * @return void
 759      */
 760     public function js_init_code($jscode, $ondomready = false, array $module = null) {
 761         $jscode = trim($jscode, " ;\n"). ';';
 762
 763         if ($module) {
 764             $this->js_module($module);
 765             $modulename = $module['name'];
 766             $jscode = "Y.use('$modulename', function(Y) { $jscode });";
 767         }
 768
 769         if ($ondomready) {
 770             $jscode = "Y.on('domready', function() { $jscode });";
 771         }
 772
 773         $this->jsinitcode[] = $jscode;
 774     }
 775
 776     /**
 777      * Make a language string available to JavaScript.
 778      *
 779      * All the strings will be available in a M.str object in the global namespace.
 780      * So, for example, after a call to $PAGE->requires->string_for_js('course', 'moodle');
 781      * then the JavaScript variable M.str.moodle.course will be 'Course', or the
 782      * equivalent in the current language.
 783      *
 784      * The arguments to this function are just like the arguments to get_string
 785      * except that $component is not optional, and there are some aspects to consider
 786      * when the string contains {$a} placeholder.
 787      *
 788      * If the string does not contain any {$a} placeholder, you can simply use
 789      * M.str.component.identifier to obtain it. If you prefer, you can call
 790      * M.util.get_string(identifier, component) to get the same result.
 791      *
 792      * If you need to use {$a} placeholders, there are two options. Either the
 793      * placeholder should be substituted in PHP on server side or it should
 794      * be substituted in Javascript at client side.
 795      *
 796      * To substitute the placeholder at server side, just provide the required
 797      * value for the placeholder when you require the string. Because each string
 798      * is only stored once in the JavaScript (based on $identifier and $module)
 799      * you cannot get the same string with two different values of $a. If you try,
 800      * an exception will be thrown. Once the placeholder is substituted, you can
 801      * use M.str or M.util.get_string() as shown above:
 802      *
 803      *     // require the string in PHP and replace the placeholder
 804      *     $PAGE->requires->string_for_js('fullnamedisplay', 'moodle', $USER);
 805      *     // use the result of the substitution in Javascript
 806      *     alert(M.str.moodle.fullnamedisplay);
 807      *
 808      * To substitute the placeholder at client side, use M.util.get_string()
 809      * function. It implements the same logic as {@see get_string()}:
 810      *
 811      *     // require the string in PHP but keep {$a} as it is
 812      *     $PAGE->requires->string_for_js('fullnamedisplay', 'moodle');
 813      *     // provide the values on the fly in Javascript
 814      *     user = { firstname : 'Harry', lastname : 'Potter' }
 815      *     alert(M.util.get_string('fullnamedisplay', 'moodle', user);
 816      *
 817      * If you do need the same string expanded with different $a values in PHP
 818      * on server side, then the solution is to put them in your own data structure
 819      * (e.g. and array) that you pass to JavaScript with {@link data_for_js()}.
 820      *
 821      * @param string $identifier the desired string.
 822      * @param string $component the language file to look in.
 823      * @param mixed $a any extra data to add into the string (optional).
 824      */
 825     public function string_for_js($identifier, $component, $a = NULL) {
 826         $string = get_string($identifier, $component, $a);
 827         if (!$component) {
 828             throw new coding_exception('The $module parameter is required for page_requirements_manager::string_for_js.');
 829         }
 830         if (isset($this->stringsforjs[$component][$identifier]) && $this->stringsforjs[$component][$identifier] !== $string) {
 831             throw new coding_exception("Attempt to re-define already required string '$identifier' " .
 832                     "from lang file '$component'. Did you already ask for it with a different \$a? {$this->stringsforjs[$component][$identifier]} !== $string");
 833         }
 834         $this->stringsforjs[$component][$identifier] = $string;
 835     }
 836
 837     /**
 838      * Make an array of language strings available for JS
 839      *
 840      * This function calls the above function {@link string_for_js()} for each requested
 841      * string in the $identifiers array that is passed to the argument for a single module
 842      * passed in $module.
 843      *
 844      * <code>
 845      * $PAGE->requires->strings_for_js(array('one', 'two', 'three'), 'mymod', array('a', null, 3));
 846      *
 847      * // The above is identitical to calling
 848      *
 849      * $PAGE->requires->string_for_js('one', 'mymod', 'a');
 850      * $PAGE->requires->string_for_js('two', 'mymod');
 851      * $PAGE->requires->string_for_js('three', 'mymod', 3);
 852      * </code>
 853      *
 854      * @param array $identifiers An array of desired strings
 855      * @param string $component The module to load for
 856      * @param mixed $a This can either be a single variable that gets passed as extra
 857      *         information for every string or it can be an array of mixed data where the
 858      *         key for the data matches that of the identifier it is meant for.
 859      *
 860      */
 861     public function strings_for_js($identifiers, $component, $a=NULL) {
 862         foreach ($identifiers as $key => $identifier) {
 863             if (is_array($a) && array_key_exists($key, $a)) {
 864                 $extra = $a[$key];
 865             } else {
 866                 $extra = $a;
 867             }
 868             $this->string_for_js($identifier, $component, $extra);
 869         }
 870     }
 871
 872     /**
 873      * !!!!!!DEPRECATED!!!!!! please use js_init_call() for everything now.
 874      *
 875      * Make some data from PHP available to JavaScript code.
 876      *
 877      * For example, if you call
 878      * <pre>
 879      *      $PAGE->requires->data_for_js('mydata', array('name' => 'Moodle'));
 880      * </pre>
 881      * then in JavsScript mydata.name will be 'Moodle'.
 882      * @param string $variable the the name of the JavaScript variable to assign the data to.
 883      *      Will probably work if you use a compound name like 'mybuttons.button[1]', but this
 884      *      should be considered an experimental feature.
 885      * @param mixed $data The data to pass to JavaScript. This will be escaped using json_encode,
 886      *      so passing objects and arrays should work.
 887      * @param bool $inhead initialise in head
 888      * @return void
 889      */
 890     public function data_for_js($variable, $data, $inhead=false) {
 891         $where = $inhead ? 'head' : 'footer';
 892         $this->jsinitvariables[$where][] = array($variable, $data);
 893     }
 894
 895     /**
 896      * Creates a YUI event handler.
 897      *
 898      * @param mixed $selector standard YUI selector for elemnts, may be array or string, element id is in the form "#idvalue"
 899      * @param string $event A valid DOM event (click, mousedown, change etc.)
 900      * @param string $function The name of the function to call
 901      * @param array  $arguments An optional array of argument parameters to pass to the function
 902      * @return void
 903      */
 904     public function event_handler($selector, $event, $function, array $arguments = null) {
 905         $this->eventhandlers[] = array('selector'=>$selector, 'event'=>$event, 'function'=>$function, 'arguments'=>$arguments);
 906     }
 907
 908     /**
 909      * Returns code needed for registering of event handlers.
 910      * @return string JS code
 911      */
 912     protected function get_event_handler_code() {
 913         $output = '';
 914         foreach ($this->eventhandlers as $h) {
 915             $output .= js_writer::event_handler($h['selector'], $h['event'], $h['function'], $h['arguments']);
 916         }
 917         return $output;
 918     }
 919
 920     /**
 921      * Get the inline JavaScript code that need to appear in a particular place.
 922      * @param bool $ondomready
 923      * @return string
 924      */
 925     protected function get_javascript_code($ondomready) {
 926         $where = $ondomready ? 'ondomready' : 'normal';
 927         $output = '';
 928         if ($this->jscalls[$where]) {
 929             foreach ($this->jscalls[$where] as $data) {
 930                 $output .= js_writer::function_call($data[0], $data[1], $data[2]);
 931             }
 932             if (!empty($ondomready)) {
 933                 $output = "    Y.on('domready', function() {\n$output\n    });";
 934             }
 935         }
 936         return $output;
 937     }
 938
 939     /**
 940      * Returns js code to be executed when Y is available.
 941      * @return unknown_type
 942      */
 943     protected function get_javascript_init_code() {
 944         if (count($this->jsinitcode)) {
 945             return implode("\n", $this->jsinitcode) . "\n";
 946         }
 947         return '';
 948     }
 949
 950     /**
 951      * Returns basic YUI3 JS loading code.
 952      * YUI3 is using autoloading of both CSS and JS code.
 953      *
 954      * Major benefit of this compared to standard js/csss loader is much improved
 955      * caching, better browser cache utilisation, much fewer http requests.
 956      *
 957      * @return string
 958      */
 959     protected function get_yui3lib_headcode() {
 960         global $CFG;
 961
 962         $code = '';
 963
 964         if ($this->yui3loader->combine) {
 965             $code .= '<link rel="stylesheet" type="text/css" href="'.$this->yui3loader->comboBase
 966                      .$CFG->yui3version.'/build/cssreset/reset-min.css&amp;'
 967                      .$CFG->yui3version.'/build/cssfonts/fonts-min.css&amp;'
 968                      .$CFG->yui3version.'/build/cssgrids/grids-min.css&amp;'
 969                      .$CFG->yui3version.'/build/cssbase/base-min.css" />';
 970         } else {
 971             $code .= '<link rel="stylesheet" type="text/css" href="'.$this->yui3loader->base.'cssreset/reset-min.css" />';
 972             $code .= '<link rel="stylesheet" type="text/css" href="'.$this->yui3loader->base.'cssfonts/fonts-min.css" />';
 973             $code .= '<link rel="stylesheet" type="text/css" href="'.$this->yui3loader->base.'cssgrids/grids-min.css" />';
 974             $code .= '<link rel="stylesheet" type="text/css" href="'.$this->yui3loader->base.'cssbase/base-min.css" />';
 975         }
 976
 977         $code .= '<script type="text/javascript" src="'.$this->yui3loader->base.'yui/yui-min.js"></script>';
 978
 979         if ($this->yui3loader->filter === YUI_RAW) {
 980             $code = str_replace('-min.css', '.css', $code);
 981             $code = str_replace('-min.js', '.js', $code);
 982         } else if ($this->yui3loader->filter === YUI_DEBUG) {
 983             $code = str_replace('-min.css', '.css', $code);
 984             $code = str_replace('-min.js', '-debug.js', $code);
 985         }
 986
 987         return $code;
 988     }
 989
 990     /**
 991      * Returns basic YUI2 JS loading code.
 992      * It can be called manually at any time.
 993      * If called manually the result needs to be output using echo().
 994      *
 995      * Major benefit of this compared to standard js loader is much improved
 996      * caching, better browser cache utilisation, much fewer http requests.
 997      *
 998      * All YUI2 CSS is loaded automatically.
 999      *
1000      * @return string JS embedding code
1001      */
1002     public function get_yui2lib_code() {
1003         global $CFG;
1004
1005         if ($this->headdone) {
1006             $code = $this->yui2loader->script();
1007         } else {
1008             $code = $this->yui2loader->script();
1009             if ($this->yui2loader->combine) {
1010                 $skinurl = $this->yui2loader->comboBase . $CFG->yui2version . '/build/assets/skins/sam/skin.css';
1011             } else {
1012                 $skinurl = $this->yui2loader->base . 'assets/skins/sam/skin.css';
1013             }
1014             // please note this is a temporary hack until we fully migrate to later YUI3 that has all the widgets
1015             $attributes = array('rel'=>'stylesheet', 'type'=>'text/css', 'href'=>$skinurl);
1016             $code .= "\n" . html_writer::empty_tag('link', $attributes) . "\n";
1017         }
1018         $code = str_replace('&amp;', '&', $code);
1019         $code = str_replace('&', '&amp;', $code);
1020         return $code;
1021     }
1022
1023     /**
1024      * Returns html tags needed for inclusion of theme CSS
1025      * @return string
1026      */
1027     protected function get_css_code() {
1028         // First of all the theme CSS, then any custom CSS
1029         // Please note custom CSS is strongly discouraged,
1030         // because it can not be overridden by themes!
1031         // It is suitable only for things like mod/data which accepts CSS from teachers.
1032         $attributes = array('rel'=>'stylesheet', 'type'=>'text/css');
1033
1034         // This line of code may look funny but it is currently required in order
1035         // to avoid MASSIVE display issues in Internet Explorer.
1036         // As of IE8 + YUI3.1.1 the reference stylesheet (firstthemesheet) gets
1037         // ignored whenever another resource is added until such time as a redraw
1038         // is forced, usually by moving the mouse over the affected element.
1039         $code = html_writer::tag('script', '/** Required in order to fix style inclusion problems in IE with YUI **/', array('id'=>'firstthemesheet', 'type'=>'text/css'));
1040
1041         $urls = $this->cssthemeurls + $this->cssurls;
1042         foreach ($urls as $url) {
1043             $attributes['href'] = $url;
1044             $code .= html_writer::empty_tag('link', $attributes) . "\n";
1045             // this id is needed in first sheet only so that theme may override YUI sheets laoded on the fly
1046             unset($attributes['id']);
1047         }
1048
1049         return $code;
1050     }
1051
1052     /**
1053      * Adds extra modules specified after printing of page header
1054      * @return string
1055      */
1056     protected function get_extra_modules_code() {
1057         if (empty($this->extramodules)) {
1058             return '';
1059         }
1060         return html_writer::script(js_writer::function_call('M.yui.add_module', array($this->extramodules)));
1061     }
1062
1063     /**
1064      * Generate any HTML that needs to go inside the <head> tag.
1065      *
1066      * Normally, this method is called automatically by the code that prints the
1067      * <head> tag. You should not normally need to call it in your own code.
1068      *
1069      * @param moodle_page $page
1070      * @param core_renderer $renderer
1071      * @return string the HTML code to to inside the <head> tag.
1072      */
1073     public function get_head_code(moodle_page $page, core_renderer $renderer) {
1074         global $CFG;
1075
1076         // note: the $page and $output are not stored here because it would
1077         // create circular references in memory which prevents garbage collection
1078         $this->init_requirements_data($page, $renderer);
1079
1080         // yui3 JS and CSS is always loaded first - it is cached in browser
1081         $output = $this->get_yui3lib_headcode();
1082
1083         // BC: load basic YUI2 for now, all yui2 things should be loaded via Y.use('yui2-oldmodulename')
1084         $output .= $this->get_yui2lib_code();
1085
1086         // now theme CSS + custom CSS in this specific order
1087         $output .= $this->get_css_code();
1088
1089         // set up global YUI3 loader object - this should contain all code needed by plugins
1090         // note: in JavaScript just use "YUI(M.yui.loader).use('overlay', function(Y) { .... });"
1091         // this needs to be done before including any other script
1092         $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";
1093         $js .= js_writer::set_variable('M.yui.loader', $this->M_yui_loader, false) . "\n";
1094         $js .= js_writer::set_variable('M.cfg', $this->M_cfg, false);
1095         $js = str_replace('"@GALLERYCONFIGFN@"', 'galleryConfigFn', $js);
1096         $js = str_replace('"@MOODLECONFIGFN@"', 'moodleConfigFn', $js);
1097
1098         $output .= html_writer::script($js);
1099
1100         // link our main JS file, all core stuff should be there
1101         $output .= html_writer::script('', $this->js_fix_url('/lib/javascript-static.js'));
1102
1103         // add variables
1104         if ($this->jsinitvariables['head']) {
1105             $js = '';
1106             foreach ($this->jsinitvariables['head'] as $data) {
1107                 list($var, $value) = $data;
1108                 $js .= js_writer::set_variable($var, $value, true);
1109             }
1110             $output .= html_writer::script($js);
1111         }
1112
1113         // all the other linked things from HEAD - there should be as few as possible
1114         if ($this->jsincludes['head']) {
1115             foreach ($this->jsincludes['head'] as $url) {
1116                 $output .= html_writer::script('', $url);
1117             }
1118         }
1119
1120         // mark head sending done, it is not possible to anything there
1121         $this->headdone = true;
1122
1123         return $output;
1124     }
1125
1126     /**
1127      * Generate any HTML that needs to go at the start of the <body> tag.
1128      *
1129      * Normally, this method is called automatically by the code that prints the
1130      * <head> tag. You should not normally need to call it in your own code.
1131      *
1132      * @return string the HTML code to go at the start of the <body> tag.
1133      */
1134     public function get_top_of_body_code() {
1135         // first the skip links
1136         $links = '';
1137         $attributes = array('class'=>'skip');
1138         foreach ($this->skiplinks as $url => $text) {
1139             $attributes['href'] = '#' . $url;
1140             $links .= html_writer::tag('a', $text, $attributes);
1141         }
1142         $output = html_writer::tag('div', $links, array('class'=>'skiplinks')) . "\n";
1143
1144         // then the clever trick for hiding of things not needed when JS works
1145         $output .= html_writer::script("document.body.className += ' jsenabled';") . "\n";
1146         $this->topofbodydone = true;
1147         return $output;
1148     }
1149
1150     /**
1151      * Generate any HTML that needs to go at the end of the page.
1152      *
1153      * Normally, this method is called automatically by the code that prints the
1154      * page footer. You should not normally need to call it in your own code.
1155      *
1156      * @return string the HTML code to to at the end of the page.
1157      */
1158     public function get_end_code() {
1159         global $CFG;
1160         // add other requested modules
1161         $output = $this->get_extra_modules_code();
1162
1163         // add missing YUI2 YUI - to be removed once we convert everything to YUI3!
1164         $output .= $this->get_yui2lib_code();
1165
1166         // all the other linked scripts - there should be as few as possible
1167         if ($this->jsincludes['footer']) {
1168             foreach ($this->jsincludes['footer'] as $url) {
1169                 $output .= html_writer::script('', $url);
1170             }
1171         }
1172
1173         // add all needed strings
1174         if (!empty($this->stringsforjs)) {
1175             $output .= html_writer::script(js_writer::set_variable('M.str', $this->stringsforjs));
1176         }
1177
1178         // add variables
1179         if ($this->jsinitvariables['footer']) {
1180             $js = '';
1181             foreach ($this->jsinitvariables['footer'] as $data) {
1182                 list($var, $value) = $data;
1183                 $js .= js_writer::set_variable($var, $value, true);
1184             }
1185             $output .= html_writer::script($js);
1186         }
1187
1188         $inyuijs = $this->get_javascript_code(false);
1189         $ondomreadyjs = $this->get_javascript_code(true);
1190         $jsinit = $this->get_javascript_init_code();
1191         $handlersjs = $this->get_event_handler_code();
1192
1193         // there is no global Y, make sure it is available in your scope
1194         $js = "YUI(M.yui.loader).use('node', function(Y) {\n{$inyuijs}{$ondomreadyjs}{$jsinit}{$handlersjs}\n});";
1195
1196         $output .= html_writer::script($js);
1197
1198         return $output;
1199     }
1200
1201     /**
1202      * @return boolean Have we already output the code in the <head> tag?
1203      */
1204     public function is_head_done() {
1205         return $this->headdone;
1206     }
1207
1208     /**
1209      * @return boolean Have we already output the code at the start of the <body> tag?
1210      */
1211     public function is_top_of_body_done() {
1212         return $this->topofbodydone;
1213     }
1214 }
1215
1216 /**
1217  * Invalidate all server and client side JS caches.
1218  * @return void
1219  */
1220 function js_reset_all_caches() {
1221     global $CFG;
1222     require_once("$CFG->libdir/filelib.php");
1223
1224     set_config('jsrev', empty($CFG->jsrev) ? 1 : $CFG->jsrev+1);
1225     fulldelete("$CFG->cachedir/js");
1226 }
1227