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)) {
 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 $output
 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', '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', '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_flashdetect':
 448                     $module = array('name'     => 'core_flashdetect',
 449                                     'fullpath' => '/lib/flashdetect/flashdetect.js',
 450                                     'requires' => array('io'));
 451                     break;
 452                 case 'core_group':
 453                     $module = array('name'     => 'core_group',
 454                                     'fullpath' => '/group/module.js',
 455                                     'requires' => array('node', 'overlay', 'event-mouseenter'));
 456                     break;
 457                 case 'core_question_engine':
 458                     $module = array('name'     => 'core_question_engine',
 459                                     'fullpath' => '/question/qengine.js',
 460                                     'requires' => array('node', 'event'));
 461                     break;
 462                 case 'core_rating':
 463                     $module = array('name'     => 'core_rating',
 464                                     'fullpath' => '/rating/module.js',
 465                                     'requires' => array('node', 'event', 'overlay', 'io', 'json'));
 466                     break;
 467                 case 'core_filetree':
 468                     $module = array('name'     => 'core_filetree',
 469                                     'fullpath' => '/files/module.js',
 470                                     'requires' => array('node', 'event', 'overlay', 'io', 'json', 'yui2-treeview'));
 471                     break;
 472             }
 473
 474         } else {
 475             if ($dir = get_component_directory($component)) {
 476                 if (file_exists("$dir/module.js")) {
 477                     if (strpos($dir, $CFG->dirroot.'/') === 0) {
 478                         $dir = substr($dir, strlen($CFG->dirroot));
 479                         $module = array('name'=>$component, 'fullpath'=>"$dir/module.js", 'requires' => array());
 480                     }
 481                 }
 482             }
 483         }
 484
 485         return $module;
 486     }
 487
 488     /**
 489      * Append YUI3 module to default YUI3 JS loader.
 490      * The structure of module array is described at http://developer.yahoo.com/yui/3/yui/:
 491      * @param string|array $module name of module (details are autodetected), or full module specification as array
 492      * @return void
 493      */
 494     public function js_module($module) {
 495         global $CFG;
 496
 497         if (empty($module)) {
 498             throw new coding_exception('Missing YUI3 module name or full description.');
 499         }
 500
 501         if (is_string($module)) {
 502             $module = $this->find_module($module);
 503         }
 504
 505         if (empty($module) or empty($module['name']) or empty($module['fullpath'])) {
 506             throw new coding_exception('Missing YUI3 module details.');
 507         }
 508
 509         // Don't load this module if we already have, no need to!
 510         if ($this->js_module_loaded($module['name'])) {
 511             if (debugging('', DEBUG_DEVELOPER)) {
 512                 $this->debug_moduleloadstacktraces[$module['name']][] = format_backtrace(debug_backtrace());
 513             }
 514             return;
 515         }
 516
 517         $module['fullpath'] = $this->js_fix_url($module['fullpath'])->out(false);
 518         // add all needed strings
 519         if (!empty($module['strings'])) {
 520             foreach ($module['strings'] as $string) {
 521                 $identifier = $string[0];
 522                 $component = isset($string[1]) ? $string[1] : 'moodle';
 523                 $a = isset($string[2]) ? $string[2] : null;
 524                 $this->string_for_js($identifier, $component, $a);
 525             }
 526         }
 527         unset($module['strings']);
 528
 529         // Process module requirements and attempt to load each. This allows
 530         // moodle modules to require each other.
 531         if (!empty($module['requires'])){
 532             foreach ($module['requires'] as $requirement) {
 533                 $rmodule = $this->find_module($requirement);
 534                 if (is_array($rmodule)) {
 535                     $this->js_module($rmodule);
 536                 }
 537             }
 538         }
 539
 540         if ($this->headdone) {
 541             $this->extramodules[$module['name']] = $module;
 542         } else {
 543             $this->M_yui_loader->modules[$module['name']] = $module;
 544         }
 545         if (debugging('', DEBUG_DEVELOPER)) {
 546             if (!array_key_exists($module['name'], $this->debug_moduleloadstacktraces)) {
 547                 $this->debug_moduleloadstacktraces[$module['name']] = array();
 548             }
 549             $this->debug_moduleloadstacktraces[$module['name']][] = format_backtrace(debug_backtrace());
 550         }
 551     }
 552
 553     /**
 554      * Returns true if the module has already been loaded.
 555      *
 556      * @param string|array $modulename
 557      * @return bool True if the module has already been loaded
 558      */
 559     protected function js_module_loaded($module) {
 560         if (is_string($module)) {
 561             $modulename = $module;
 562         } else {
 563             $modulename = $module['name'];
 564         }
 565         return array_key_exists($modulename, $this->M_yui_loader->modules) ||
 566                array_key_exists($modulename, $this->extramodules);
 567     }
 568
 569     /**
 570      * Returns the stacktraces from loading js modules.
 571      * @return array
 572      */
 573     public function get_loaded_modules() {
 574         return $this->debug_moduleloadstacktraces;
 575     }
 576
 577     /**
 578      * Ensure that the specified CSS file is linked to from this page.
 579      *
 580      * Because stylesheet links must go in the <head> part of the HTML, you must call
 581      * this function before {@link get_head_code()} is called. That normally means before
 582      * the call to print_header. If you call it when it is too late, an exception
 583      * will be thrown.
 584      *
 585      * Even if a particular style sheet is requested more than once, it will only
 586      * be linked to once.
 587      *
 588      * Please note use of this feature is strongly discouraged,
 589      * it is suitable only for places where CSS is submitted directly by teachers.
 590      * (Students must not be allowed to submit any external CSS because it may
 591      * contain embedded javascript!). Example of correct use is mod/data.
 592      *
 593      * @param string $stylesheet The path to the .css file, relative to $CFG->wwwroot.
 594      *   For example:
 595      *      $PAGE->requires->css('mod/data/css.php?d='.$data->id);
 596      */
 597     public function css($stylesheet) {
 598         global $CFG;
 599
 600         if ($this->headdone) {
 601             throw new coding_exception('Cannot require a CSS file after &lt;head> has been printed.', $stylesheet);
 602         }
 603
 604         if ($stylesheet instanceof moodle_url) {
 605             // ok
 606         } else if (strpos($stylesheet, '/') === 0) {
 607             $stylesheet = new moodle_url($CFG->httpswwwroot.$stylesheet);
 608         } else {
 609             throw new coding_exception('Invalid stylesheet parameter.', $stylesheet);
 610         }
 611
 612         $this->cssurls[$stylesheet->out()] = $stylesheet; // overrides
 613     }
 614
 615     /**
 616      * Add theme stylkesheet to page - do not use from plugin code,
 617      * this should be called only from the core renderer!
 618      * @param moodle_url $stylesheet
 619      * @return void
 620      */
 621     public function css_theme(moodle_url $stylesheet) {
 622         $this->cssthemeurls[] = $stylesheet;
 623     }
 624
 625     /**
 626      * Ensure that a skip link to a given target is printed at the top of the <body>.
 627      *
 628      * You must call this function before {@link get_top_of_body_code()}, (if not, an exception
 629      * will be thrown). That normally means you must call this before the call to print_header.
 630      *
 631      * If you ask for a particular skip link to be printed, it is then your responsibility
 632      * to ensure that the appropriate <a name="..."> tag is printed in the body of the
 633      * page, so that the skip link goes somewhere.
 634      *
 635      * Even if a particular skip link is requested more than once, only one copy of it will be output.
 636      *
 637      * @param $target the name of anchor this link should go to. For example 'maincontent'.
 638      * @param $linktext The text to use for the skip link. Normally get_string('skipto', 'access', ...);
 639      */
 640     public function skip_link_to($target, $linktext) {
 641         if ($this->topofbodydone) {
 642             debugging('Page header already printed, can not add skip links any more, code needs to be fixed.');
 643             return;
 644         }
 645         $this->skiplinks[$target] = $linktext;
 646     }
 647
 648     /**
 649      * !!!DEPRECATED!!! please use js_init_call() if possible
 650      * Ensure that the specified JavaScript function is called from an inline script
 651      * somewhere on this page.
 652      *
 653      * By default the call will be put in a script tag at the
 654      * end of the page after initialising Y instance, since this gives best page-load
 655      * performance and allows you to use YUI3 library.
 656      *
 657      * If you request that a particular function is called several times, then
 658      * that is what will happen (unlike linking to a CSS or JS file, where only
 659      * one link will be output).
 660      *
 661      * The main benefit of the method is the automatic encoding of all function parameters.
 662      *
 663      * @param string $function the name of the JavaScritp function to call. Can
 664      *      be a compound name like 'Y.Event.purgeElement'. Can also be
 665      *      used to create and object by using a 'function name' like 'new user_selector'.
 666      * @param array $arguments and array of arguments to be passed to the function.
 667      *      When generating the function call, this will be escaped using json_encode,
 668      *      so passing objects and arrays should work.
 669      * @param bool $ondomready
 670      * @param int $delay
 671      * @return void
 672      */
 673     public function js_function_call($function, array $arguments = null, $ondomready = false, $delay = 0) {
 674         $where = $ondomready ? 'ondomready' : 'normal';
 675         $this->jscalls[$where][] = array($function, $arguments, $delay);
 676     }
 677
 678     /**
 679      * Adds a call to make use of a YUI gallery module. DEPRECATED DO NOT USE!!!
 680      *
 681      * @deprecated DO NOT USE
 682      *
 683      * @param string|array $modules One or more gallery modules to require
 684      * @param string $version
 685      * @param string $function
 686      * @param array $arguments
 687      * @param bool $ondomready
 688      */
 689     public function js_gallery_module($modules, $version, $function, array $arguments = null, $ondomready = false) {
 690         global $CFG;
 691         debugging('This function will be removed before 2.0 is released please change it from js_gallery_module to yui_module', DEBUG_DEVELOPER);
 692         $this->yui_module($modules, $function, $arguments, $version, $ondomready);
 693     }
 694
 695     /**
 696      * Creates a JavaScript function call that requires one or more modules to be loaded
 697      *
 698      * This function can be used to include all of the standard YUI module types within JavaScript:
 699      *     - YUI3 modules    [node, event, io]
 700      *     - YUI2 modules    [yui2-*]
 701      *     - Moodle modules  [moodle-*]
 702      *     - Gallery modules [gallery-*]
 703      *
 704      * @param array|string $modules One or more modules
 705      * @param string $function The function to call once modules have been loaded
 706      * @param array $arguments An array of arguments to pass to the function
 707      * @param string $galleryversion The gallery version to use
 708      * @param bool $ondomready
 709      */
 710     public function yui_module($modules, $function, array $arguments = null, $galleryversion = '2010.04.08-12-35', $ondomready = false) {
 711         global $CFG;
 712
 713         if (!is_array($modules)) {
 714             $modules = array($modules);
 715         }
 716         if (empty($CFG->useexternalyui) || true) {
 717             // We need to set the M.yui.galleryversion to the correct version
 718             $jscode = 'M.yui.galleryversion='.json_encode($galleryversion).';';
 719         } else {
 720             // Set Y's config.gallery to the version
 721             $jscode = 'Y.config.gallery='.json_encode($galleryversion).';';
 722         }
 723         $jscode .= 'Y.use('.join(',', array_map('json_encode', $modules)).',function() {'.js_writer::function_call($function, $arguments).'});';
 724         if ($ondomready) {
 725             $jscode = "Y.on('domready', function() { $jscode });";
 726         }
 727         $this->jsinitcode[] = $jscode;
 728     }
 729
 730     /**
 731      * Ensure that the specified JavaScript function is called from an inline script
 732      * from page footer.
 733      *
 734      * @param string $function the name of the JavaScritp function to with init code,
 735      *      usually something like 'M.mod_mymodule.init'
 736      * @param array $extraarguments and array of arguments to be passed to the function.
 737      *      The first argument is always the YUI3 Y instance with all required dependencies
 738      *      already loaded.
 739      * @param bool $ondomready wait for dom ready (helps with some IE problems when modifying DOM)
 740      * @param array $module JS module specification array
 741      * @return void
 742      */
 743     public function js_init_call($function, array $extraarguments = null, $ondomready = false, array $module = null) {
 744         $jscode = js_writer::function_call_with_Y($function, $extraarguments);
 745         if (!$module) {
 746             // detect module automatically
 747             if (preg_match('/M\.([a-z0-9]+_[^\.]+)/', $function, $matches)) {
 748                 $module = $this->find_module($matches[1]);
 749             }
 750         }
 751
 752         $this->js_init_code($jscode, $ondomready, $module);
 753     }
 754
 755     /**
 756      * Add short static javascript code fragment to page footer.
 757      * This is intended primarily for loading of js modules and initialising page layout.
 758      * Ideally the JS code fragment should be stored in plugin renderer so that themes
 759      * may override it.
 760      * @param string $jscode
 761      * @param bool $ondomready wait for dom ready (helps with some IE problems when modifying DOM)
 762      * @param array $module JS module specification array
 763      * @return void
 764      */
 765     public function js_init_code($jscode, $ondomready = false, array $module = null) {
 766         $jscode = trim($jscode, " ;\n"). ';';
 767
 768         if ($module) {
 769             $this->js_module($module);
 770             $modulename = $module['name'];
 771             $jscode = "Y.use('$modulename', function(Y) { $jscode });";
 772         }
 773
 774         if ($ondomready) {
 775             $jscode = "Y.on('domready', function() { $jscode });";
 776         }
 777
 778         $this->jsinitcode[] = $jscode;
 779     }
 780
 781     /**
 782      * Make a language string available to JavaScript.
 783      *
 784      * All the strings will be available in a M.str object in the global namespace.
 785      * So, for example, after a call to $PAGE->requires->string_for_js('course', 'moodle');
 786      * then the JavaScript variable M.str.moodle.course will be 'Course', or the
 787      * equivalent in the current language.
 788      *
 789      * The arguments to this function are just like the arguments to get_string
 790      * except that $component is not optional, and there are some aspects to consider
 791      * when the string contains {$a} placeholder.
 792      *
 793      * If the string does not contain any {$a} placeholder, you can simply use
 794      * M.str.component.identifier to obtain it. If you prefer, you can call
 795      * M.util.get_string(identifier, component) to get the same result.
 796      *
 797      * If you need to use {$a} placeholders, there are two options. Either the
 798      * placeholder should be substituted in PHP on server side or it should
 799      * be substituted in Javascript at client side.
 800      *
 801      * To substitute the placeholder at server side, just provide the required
 802      * value for the placeholder when you require the string. Because each string
 803      * is only stored once in the JavaScript (based on $identifier and $module)
 804      * you cannot get the same string with two different values of $a. If you try,
 805      * an exception will be thrown. Once the placeholder is substituted, you can
 806      * use M.str or M.util.get_string() as shown above:
 807      *
 808      *     // require the string in PHP and replace the placeholder
 809      *     $PAGE->requires->string_for_js('fullnamedisplay', 'moodle', $USER);
 810      *     // use the result of the substitution in Javascript
 811      *     alert(M.str.moodle.fullnamedisplay);
 812      *
 813      * To substitute the placeholder at client side, use M.util.get_string()
 814      * function. It implements the same logic as {@see get_string()}:
 815      *
 816      *     // require the string in PHP but keep {$a} as it is
 817      *     $PAGE->requires->string_for_js('fullnamedisplay', 'moodle');
 818      *     // provide the values on the fly in Javascript
 819      *     user = { firstname : 'Harry', lastname : 'Potter' }
 820      *     alert(M.util.get_string('fullnamedisplay', 'moodle', user);
 821      *
 822      * If you do need the same string expanded with different $a values in PHP
 823      * on server side, then the solution is to put them in your own data structure
 824      * (e.g. and array) that you pass to JavaScript with {@link data_for_js()}.
 825      *
 826      * @param string $identifier the desired string.
 827      * @param string $module the language file to look in.
 828      * @param mixed $a any extra data to add into the string (optional).
 829      */
 830     public function string_for_js($identifier, $component, $a = NULL) {
 831         $string = get_string($identifier, $component, $a);
 832         if (!$component) {
 833             throw new coding_exception('The $module parameter is required for page_requirements_manager::string_for_js.');
 834         }
 835         if (isset($this->stringsforjs[$component][$identifier]) && $this->stringsforjs[$component][$identifier] !== $string) {
 836             throw new coding_exception("Attempt to re-define already required string '$identifier' " .
 837                     "from lang file '$component'. Did you already ask for it with a different \$a? {$this->stringsforjs[$component][$identifier]} !== $string");
 838         }
 839         $this->stringsforjs[$component][$identifier] = $string;
 840     }
 841
 842     /**
 843      * Make an array of language strings available for JS
 844      *
 845      * This function calls the above function {@link string_for_js()} for each requested
 846      * string in the $identifiers array that is passed to the argument for a single module
 847      * passed in $module.
 848      *
 849      * <code>
 850      * $PAGE->requires->strings_for_js(array('one', 'two', 'three'), 'mymod', array('a', null, 3));
 851      *
 852      * // The above is identitical to calling
 853      *
 854      * $PAGE->requires->string_for_js('one', 'mymod', 'a');
 855      * $PAGE->requires->string_for_js('two', 'mymod');
 856      * $PAGE->requires->string_for_js('three', 'mymod', 3);
 857      * </code>
 858      *
 859      * @param array $identifiers An array of desired strings
 860      * @param string $component The module to load for
 861      * @param mixed $a This can either be a single variable that gets passed as extra
 862      *         information for every string or it can be an array of mixed data where the
 863      *         key for the data matches that of the identifier it is meant for.
 864      *
 865      */
 866     public function strings_for_js($identifiers, $component, $a=NULL) {
 867         foreach ($identifiers as $key => $identifier) {
 868             if (is_array($a) && array_key_exists($key, $a)) {
 869                 $extra = $a[$key];
 870             } else {
 871                 $extra = $a;
 872             }
 873             $this->string_for_js($identifier, $component, $extra);
 874         }
 875     }
 876
 877     /**
 878      * !!!!!!DEPRECATED!!!!!! please use js_init_call() for everything now.
 879      *
 880      * Make some data from PHP available to JavaScript code.
 881      *
 882      * For example, if you call
 883      * <pre>
 884      *      $PAGE->requires->data_for_js('mydata', array('name' => 'Moodle'));
 885      * </pre>
 886      * then in JavsScript mydata.name will be 'Moodle'.
 887      * @param string $variable the the name of the JavaScript variable to assign the data to.
 888      *      Will probably work if you use a compound name like 'mybuttons.button[1]', but this
 889      *      should be considered an experimental feature.
 890      * @param mixed $data The data to pass to JavaScript. This will be escaped using json_encode,
 891      *      so passing objects and arrays should work.
 892      * @param bool $inhead initialise in head
 893      * @return void
 894      */
 895     public function data_for_js($variable, $data, $inhead=false) {
 896         $where = $inhead ? 'head' : 'footer';
 897         $this->jsinitvariables[$where][] = array($variable, $data);
 898     }
 899
 900     /**
 901      * Creates a YUI event handler.
 902      *
 903      * @param mixed $selector standard YUI selector for elemnts, may be array or string, element id is in the form "#idvalue"
 904      * @param string $event A valid DOM event (click, mousedown, change etc.)
 905      * @param string $function The name of the function to call
 906      * @param array  $arguments An optional array of argument parameters to pass to the function
 907      * @return void
 908      */
 909     public function event_handler($selector, $event, $function, array $arguments = null) {
 910         $this->eventhandlers[] = array('selector'=>$selector, 'event'=>$event, 'function'=>$function, 'arguments'=>$arguments);
 911     }
 912
 913     /**
 914      * Returns code needed for registering of event handlers.
 915      * @return string JS code
 916      */
 917     protected function get_event_handler_code() {
 918         $output = '';
 919         foreach ($this->eventhandlers as $h) {
 920             $output .= js_writer::event_handler($h['selector'], $h['event'], $h['function'], $h['arguments']);
 921         }
 922         return $output;
 923     }
 924
 925     /**
 926      * Get the inline JavaScript code that need to appear in a particular place.
 927      * @return bool $ondomready
 928      */
 929     protected function get_javascript_code($ondomready) {
 930         $where = $ondomready ? 'ondomready' : 'normal';
 931         $output = '';
 932         if ($this->jscalls[$where]) {
 933             foreach ($this->jscalls[$where] as $data) {
 934                 $output .= js_writer::function_call($data[0], $data[1], $data[2]);
 935             }
 936             if (!empty($ondomready)) {
 937                 $output = "    Y.on('domready', function() {\n$output\n    });";
 938             }
 939         }
 940         return $output;
 941     }
 942
 943     /**
 944      * Returns js code to be executed when Y is available.
 945      * @return unknown_type
 946      */
 947     protected function get_javascript_init_code() {
 948         if (count($this->jsinitcode)) {
 949             return implode("\n", $this->jsinitcode) . "\n";
 950         }
 951         return '';
 952     }
 953
 954     /**
 955      * Returns basic YUI3 JS loading code.
 956      * YUI3 is using autoloading of both CSS and JS code.
 957      *
 958      * Major benefit of this compared to standard js/csss loader is much improved
 959      * caching, better browser cache utilisation, much fewer http requests.
 960      *
 961      * @return string
 962      */
 963     protected function get_yui3lib_headcode() {
 964         global $CFG;
 965
 966         $code = '';
 967
 968         if ($this->yui3loader->combine) {
 969             $code .= '<link rel="stylesheet" type="text/css" href="'.$this->yui3loader->comboBase
 970                      .$CFG->yui3version.'/build/cssreset/reset-min.css&amp;'
 971                      .$CFG->yui3version.'/build/cssfonts/fonts-min.css&amp;'
 972                      .$CFG->yui3version.'/build/cssgrids/grids-min.css&amp;'
 973                      .$CFG->yui3version.'/build/cssbase/base-min.css" />';
 974         } else {
 975             $code .= '<link rel="stylesheet" type="text/css" href="'.$this->yui3loader->base.'cssreset/reset-min.css" />';
 976             $code .= '<link rel="stylesheet" type="text/css" href="'.$this->yui3loader->base.'cssfonts/fonts-min.css" />';
 977             $code .= '<link rel="stylesheet" type="text/css" href="'.$this->yui3loader->base.'cssgrids/grids-min.css" />';
 978             $code .= '<link rel="stylesheet" type="text/css" href="'.$this->yui3loader->base.'cssbase/base-min.css" />';
 979         }
 980
 981         $code .= '<script type="text/javascript" src="'.$this->yui3loader->base.'yui/yui-min.js"></script>';
 982
 983         if ($this->yui3loader->filter === YUI_RAW) {
 984             $code = str_replace('-min.css', '.css', $code);
 985             $code = str_replace('-min.js', '.js', $code);
 986         } else if ($this->yui3loader->filter === YUI_DEBUG) {
 987             $code = str_replace('-min.css', '.css', $code);
 988             $code = str_replace('-min.js', '-debug.js', $code);
 989         }
 990
 991         return $code;
 992     }
 993
 994     /**
 995      * Returns basic YUI2 JS loading code.
 996      * It can be called manually at any time.
 997      * If called manually the result needs to be output using echo().
 998      *
 999      * Major benefit of this compared to standard js loader is much improved
1000      * caching, better browser cache utilisation, much fewer http requests.
1001      *
1002      * All YUI2 CSS is loaded automatically.
1003      *
1004      * @return string JS embedding code
1005      */
1006     public function get_yui2lib_code() {
1007         global $CFG;
1008
1009         if ($this->headdone) {
1010             $code = $this->yui2loader->script();
1011         } else {
1012             $code = $this->yui2loader->script();
1013             if ($this->yui2loader->combine) {
1014                 $skinurl = $this->yui2loader->comboBase . $CFG->yui2version . '/build/assets/skins/sam/skin.css';
1015             } else {
1016                 $skinurl = $this->yui2loader->base . 'assets/skins/sam/skin.css';
1017             }
1018             // please note this is a temporary hack until we fully migrate to later YUI3 that has all the widgets
1019             $attributes = array('rel'=>'stylesheet', 'type'=>'text/css', 'href'=>$skinurl);
1020             $code .= "\n" . html_writer::empty_tag('link', $attributes) . "\n";
1021         }
1022         $code = str_replace('&amp;', '&', $code);
1023         $code = str_replace('&', '&amp;', $code);
1024         return $code;
1025     }
1026
1027     /**
1028      * Returns html tags needed for inclusion of theme CSS
1029      * @return string
1030      */
1031     protected function get_css_code() {
1032         // First of all the theme CSS, then any custom CSS
1033         // Please note custom CSS is strongly discouraged,
1034         // because it can not be overridden by themes!
1035         // It is suitable only for things like mod/data which accepts CSS from teachers.
1036         $attributes = array('rel'=>'stylesheet', 'type'=>'text/css');
1037
1038         // This line of code may look funny but it is currently required in order
1039         // to avoid MASSIVE display issues in Internet Explorer.
1040         // As of IE8 + YUI3.1.1 the reference stylesheet (firstthemesheet) gets
1041         // ignored whenever another resource is added until such time as a redraw
1042         // is forced, usually by moving the mouse over the affected element.
1043         $code = html_writer::tag('script', '/** Required in order to fix style inclusion problems in IE with YUI **/', array('id'=>'firstthemesheet', 'type'=>'text/css'));
1044
1045         $urls = $this->cssthemeurls + $this->cssurls;
1046         foreach ($urls as $url) {
1047             $attributes['href'] = $url;
1048             $code .= html_writer::empty_tag('link', $attributes) . "\n";
1049             // this id is needed in first sheet only so that theme may override YUI sheets laoded on the fly
1050             unset($attributes['id']);
1051         }
1052
1053         return $code;
1054     }
1055
1056     /**
1057      * Adds extra modules specified after printing of page header
1058      */
1059     protected function get_extra_modules_code() {
1060         if (empty($this->extramodules)) {
1061             return '';
1062         }
1063         return html_writer::script(js_writer::function_call('M.yui.add_module', array($this->extramodules)));
1064     }
1065
1066     /**
1067      * Generate any HTML that needs to go inside the <head> tag.
1068      *
1069      * Normally, this method is called automatically by the code that prints the
1070      * <head> tag. You should not normally need to call it in your own code.
1071      *
1072      * @return string the HTML code to to inside the <head> tag.
1073      */
1074     public function get_head_code(moodle_page $page, core_renderer $renderer) {
1075         global $CFG;
1076
1077         // note: the $page and $output are not stored here because it would
1078         // create circular references in memory which prevents garbage collection
1079         $this->init_requirements_data($page, $renderer);
1080
1081         // yui3 JS and CSS is always loaded first - it is cached in browser
1082         $output = $this->get_yui3lib_headcode();
1083
1084         // BC: load basic YUI2 for now, all yui2 things should be loaded via Y.use('yui2-oldmodulename')
1085         $output .= $this->get_yui2lib_code();
1086
1087         // now theme CSS + custom CSS in this specific order
1088         $output .= $this->get_css_code();
1089
1090         // set up global YUI3 loader object - this should contain all code needed by plugins
1091         // note: in JavaScript just use "YUI(M.yui.loader).use('overlay', function(Y) { .... });"
1092         // this needs to be done before including any other script
1093         $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";
1094         $js .= js_writer::set_variable('M.yui.loader', $this->M_yui_loader, false) . "\n";
1095         $js .= js_writer::set_variable('M.cfg', $this->M_cfg, false);
1096         $js = str_replace('"@GALLERYCONFIGFN@"', 'galleryConfigFn', $js);
1097         $js = str_replace('"@MOODLECONFIGFN@"', 'moodleConfigFn', $js);
1098
1099         $output .= html_writer::script($js);
1100
1101         // link our main JS file, all core stuff should be there
1102         $output .= html_writer::script('', $this->js_fix_url('/lib/javascript-static.js'));
1103
1104         // add variables
1105         if ($this->jsinitvariables['head']) {
1106             $js = '';
1107             foreach ($this->jsinitvariables['head'] as $data) {
1108                 list($var, $value) = $data;
1109                 $js .= js_writer::set_variable($var, $value, true);
1110             }
1111             $output .= html_writer::script($js);
1112         }
1113
1114         // all the other linked things from HEAD - there should be as few as possible
1115         if ($this->jsincludes['head']) {
1116             foreach ($this->jsincludes['head'] as $url) {
1117                 $output .= html_writer::script('', $url);
1118             }
1119         }
1120
1121         // mark head sending done, it is not possible to anything there
1122         $this->headdone = true;
1123
1124         return $output;
1125     }
1126
1127     /**
1128      * Generate any HTML that needs to go at the start of the <body> tag.
1129      *
1130      * Normally, this method is called automatically by the code that prints the
1131      * <head> tag. You should not normally need to call it in your own code.
1132      *
1133      * @return string the HTML code to go at the start of the <body> tag.
1134      */
1135     public function get_top_of_body_code() {
1136         // first the skip links
1137         $links = '';
1138         $attributes = array('class'=>'skip');
1139         foreach ($this->skiplinks as $url => $text) {
1140             $attributes['href'] = '#' . $url;
1141             $links .= html_writer::tag('a', $text, $attributes);
1142         }
1143         $output = html_writer::tag('div', $links, array('class'=>'skiplinks')) . "\n";
1144
1145         // then the clever trick for hiding of things not needed when JS works
1146         $output .= html_writer::script("document.body.className += ' jsenabled';") . "\n";
1147         $this->topofbodydone = true;
1148         return $output;
1149     }
1150
1151     /**
1152      * Generate any HTML that needs to go at the end of the page.
1153      *
1154      * Normally, this method is called automatically by the code that prints the
1155      * page footer. You should not normally need to call it in your own code.
1156      *
1157      * @return string the HTML code to to at the end of the page.
1158      */
1159     public function get_end_code() {
1160         global $CFG;
1161         // add other requested modules
1162         $output = $this->get_extra_modules_code();
1163
1164         // add missing YUI2 YUI - to be removed once we convert everything to YUI3!
1165         $output .= $this->get_yui2lib_code();
1166
1167         // all the other linked scripts - there should be as few as possible
1168         if ($this->jsincludes['footer']) {
1169             foreach ($this->jsincludes['footer'] as $url) {
1170                 $output .= html_writer::script('', $url);
1171             }
1172         }
1173
1174         // add all needed strings
1175         if (!empty($this->stringsforjs)) {
1176             $output .= html_writer::script(js_writer::set_variable('M.str', $this->stringsforjs));
1177         }
1178
1179         // add variables
1180         if ($this->jsinitvariables['footer']) {
1181             $js = '';
1182             foreach ($this->jsinitvariables['footer'] as $data) {
1183                 list($var, $value) = $data;
1184                 $js .= js_writer::set_variable($var, $value, true);
1185             }
1186             $output .= html_writer::script($js);
1187         }
1188
1189         $inyuijs = $this->get_javascript_code(false);
1190         $ondomreadyjs = $this->get_javascript_code(true);
1191         $jsinit = $this->get_javascript_init_code();
1192         $handlersjs = $this->get_event_handler_code();
1193
1194         // there is no global Y, make sure it is available in your scope
1195         $js = "YUI(M.yui.loader).use('node', function(Y) {\n{$inyuijs}{$ondomreadyjs}{$jsinit}{$handlersjs}\n});";
1196
1197         $output .= html_writer::script($js);
1198
1199         return $output;
1200     }
1201
1202     /**
1203      * @return boolean Have we already output the code in the <head> tag?
1204      */
1205     public function is_head_done() {
1206         return $this->headdone;
1207     }
1208
1209     /**
1210      * @return boolean Have we already output the code at the start of the <body> tag?
1211      */
1212     public function is_top_of_body_done() {
1213         return $this->topofbodydone;
1214     }
1215 }
1216
1217 /**
1218  * Invalidate all server and client side JS caches.
1219  * @return void
1220  */
1221 function js_reset_all_caches() {
1222     global $CFG;
1223     require_once("$CFG->libdir/filelib.php");
1224
1225     set_config('jsrev', empty($CFG->jsrev) ? 1 : $CFG->jsrev+1);
1226     fulldelete("$CFG->dataroot/cache/js");
1227 }
1228