lib/outputrequirementslib.php

   1 <?php
   2 // This file is part of Moodle - http://moodle.org/
   3 //
   4 // Moodle is free software: you can redistribute it and/or modify
   5 // it under the terms of the GNU General Public License as published by
   6 // the Free Software Foundation, either version 3 of the License, or
   7 // (at your option) any later version.
   8 //
   9 // Moodle is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13 //
  14 // You should have received a copy of the GNU General Public License
  15 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  16
  17 /**
  18  * Library functions to facilitate the use of JavaScript in Moodle.
  19  *
  20  * Note: you can find history of this file in lib/ajax/ajaxlib.php
  21  *
  22  * @copyright 2009 Tim Hunt, 2010 Petr Skoda
  23  * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  24  * @package core
  25  * @category output
  26  */
  27
  28 defined('MOODLE_INTERNAL') || die();
  29
  30 /**
  31  * This class tracks all the things that are needed by the current page.
  32  *
  33  * Normally, the only instance of this  class you will need to work with is the
  34  * one accessible via $PAGE->requires.
  35  *
  36  * Typical usage would be
  37  * <pre>
  38  *     $PAGE->requires->js_init_call('M.mod_forum.init_view');
  39  * </pre>
  40  *
  41  * It also supports obsoleted coding style withouth YUI3 modules.
  42  * <pre>
  43  *     $PAGE->requires->css('/mod/mymod/userstyles.php?id='.$id); // not overridable via themes!
  44  *     $PAGE->requires->js('/mod/mymod/script.js');
  45  *     $PAGE->requires->js('/mod/mymod/small_but_urgent.js', true);
  46  *     $PAGE->requires->js_function_call('init_mymod', array($data), true);
  47  * </pre>
  48  *
  49  * There are some natural restrictions on some methods. For example, {@link css()}
  50  * can only be called before the <head> tag is output. See the comments on the
  51  * individual methods for details.
  52  *
  53  * @copyright 2009 Tim Hunt, 2010 Petr Skoda
  54  * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  55  * @since Moodle 2.0
  56  * @package core
  57  * @category output
  58  */
  59 class page_requirements_manager {
  60
  61     /**
  62      * @var array List of string available from JS
  63      */
  64     protected $stringsforjs = array();
  65
  66     /**
  67      * @var array List of get_string $a parameters - used for validation only.
  68      */
  69     protected $stringsforjs_as = array();
  70
  71     /**
  72      * @var array List of JS variables to be initialised
  73      */
  74     protected $jsinitvariables = array('head'=>array(), 'footer'=>array());
  75
  76     /**
  77      * @var array Included JS scripts
  78      */
  79     protected $jsincludes = array('head'=>array(), 'footer'=>array());
  80
  81     /**
  82      * @var array List of needed function calls
  83      */
  84     protected $jscalls = array('normal'=>array(), 'ondomready'=>array());
  85
  86     /**
  87      * @var array List of skip links, those are needed for accessibility reasons
  88      */
  89     protected $skiplinks = array();
  90
  91     /**
  92      * @var array Javascript code used for initialisation of page, it should
  93      * be relatively small
  94      */
  95     protected $jsinitcode = array();
  96
  97     /**
  98      * @var array of moodle_url Theme sheets, initialised only from core_renderer
  99      */
 100     protected $cssthemeurls = array();
 101
 102     /**
 103      * @var array of moodle_url List of custom theme sheets, these are strongly discouraged!
 104      * Useful mostly only for CSS submitted by teachers that is not part of the theme.
 105      */
 106     protected $cssurls = array();
 107
 108     /**
 109      * @var array List of requested event handlers
 110      */
 111     protected $eventhandlers = array();
 112
 113     /**
 114      * @var array Extra modules
 115      */
 116     protected $extramodules = array();
 117
 118     /**
 119      * @var bool Flag indicated head stuff already printed
 120      */
 121     protected $headdone = false;
 122
 123     /**
 124      * @var bool Flag indicating top of body already printed
 125      */
 126     protected $topofbodydone = false;
 127
 128     /**
 129      * @var stdClass YUI PHPLoader instance responsible for YUI3 loading from PHP only
 130      */
 131     protected $yui3loader;
 132
 133     /**
 134      * @var YUI_config default YUI loader configuration
 135      */
 136     protected $YUI_config;
 137
 138     /**
 139      * @var array Some config vars exposed in JS, please no secret stuff there
 140      */
 141     protected $M_cfg;
 142
 143     /**
 144      * @var array list of requested jQuery plugins
 145      */
 146     protected $jqueryplugins = array();
 147
 148     /**
 149      * @var array list of jQuery plugin overrides
 150      */
 151     protected $jquerypluginoverrides = array();
 152
 153     /**
 154      * Page requirements constructor.
 155      */
 156     public function __construct() {
 157         global $CFG;
 158
 159         // You may need to set up URL rewrite rule because oversized URLs might not be allowed by web server.
 160         $sep = empty($CFG->yuislasharguments) ? '?' : '/';
 161
 162         $this->yui3loader = new stdClass();
 163         $this->YUI_config = new YUI_config();
 164
 165         if (strpos($CFG->httpswwwroot, 'https:') === 0) {
 166             // On HTTPS sites all JS must be loaded from https sites,
 167             // YUI CDN does not support https yet, sorry.
 168             $CFG->useexternalyui = 0;
 169         }
 170
 171         // Set up some loader options.
 172         $this->yui3loader->local_base = $CFG->httpswwwroot . '/lib/yuilib/'. $CFG->yui3version . '/';
 173         $this->yui3loader->local_comboBase = $CFG->httpswwwroot . '/theme/yui_combo.php'.$sep;
 174
 175         if (!empty($CFG->useexternalyui)) {
 176             $this->yui3loader->base = 'http://yui.yahooapis.com/' . $CFG->yui3version . '/';
 177             $this->yui3loader->comboBase = 'http://yui.yahooapis.com/combo?';
 178         } else {
 179             $this->yui3loader->base = $this->yui3loader->local_base;
 180             $this->yui3loader->comboBase = $this->yui3loader->local_comboBase;
 181         }
 182
 183         // Enable combo loader? This significantly helps with caching and performance!
 184         $this->yui3loader->combine = !empty($CFG->yuicomboloading);
 185
 186         $jsrev = $this->get_jsrev();
 187
 188         // Set up JS YUI loader helper object.
 189         $this->YUI_config->base         = $this->yui3loader->base;
 190         $this->YUI_config->comboBase    = $this->yui3loader->comboBase;
 191         $this->YUI_config->combine      = $this->yui3loader->combine;
 192
 193         // If we've had to patch any YUI modules between releases, we must override the YUI configuration to include them.
 194         // For important information on patching YUI modules, please see http://docs.moodle.org/dev/YUI/Patching.
 195         if (!empty($CFG->yuipatchedmodules) && !empty($CFG->yuipatchlevel)) {
 196             $this->YUI_config->define_patched_core_modules($this->yui3loader->local_comboBase,
 197                     $CFG->yui3version,
 198                     $CFG->yuipatchlevel,
 199                     $CFG->yuipatchedmodules);
 200         }
 201
 202         $configname = $this->YUI_config->set_config_source('lib/yui/config/yui2.js');
 203         $this->YUI_config->add_group('yui2', array(
 204             // Loader configuration for our 2in3, for now ignores $CFG->useexternalyui.
 205             'base' => $CFG->httpswwwroot . '/lib/yuilib/2in3/' . $CFG->yui2version . '/build/',
 206             'comboBase' => $CFG->httpswwwroot . '/theme/yui_combo.php'.$sep,
 207             'combine' => $this->yui3loader->combine,
 208             'ext' => false,
 209             'root' => '2in3/' . $CFG->yui2version .'/build/',
 210             'patterns' => array(
 211                 'yui2-' => array(
 212                     'group' => 'yui2',
 213                     'configFn' => $configname,
 214                 )
 215             )
 216         ));
 217         $configname = $this->YUI_config->set_config_source('lib/yui/config/moodle.js');
 218         $this->YUI_config->add_group('moodle', array(
 219             'name' => 'moodle',
 220             'base' => $CFG->httpswwwroot . '/theme/yui_combo.php' . $sep . 'm/' . $jsrev . '/',
 221             'combine' => $this->yui3loader->combine,
 222             'comboBase' => $CFG->httpswwwroot . '/theme/yui_combo.php'.$sep,
 223             'ext' => false,
 224             'root' => 'm/'.$jsrev.'/', // Add the rev to the root path so that we can control caching.
 225             'patterns' => array(
 226                 'moodle-' => array(
 227                     'group' => 'moodle',
 228                     'configFn' => $configname,
 229                 )
 230             )
 231         ));
 232
 233         $this->YUI_config->add_group('gallery', array(
 234             'name' => 'gallery',
 235             'base' => $CFG->httpswwwroot . '/lib/yuilib/gallery/',
 236             'combine' => $this->yui3loader->combine,
 237             'comboBase' => $CFG->httpswwwroot . '/theme/yui_combo.php' . $sep,
 238             'ext' => false,
 239             'root' => 'gallery/' . $jsrev . '/',
 240             'patterns' => array(
 241                 'gallery-' => array(
 242                     'group' => 'gallery',
 243                 )
 244             )
 245         ));
 246
 247         // Set some more loader options applying to groups too.
 248         if ($CFG->debugdeveloper) {
 249             // When debugging is enabled, we want to load the non-minified (RAW) versions of YUI library modules rather
 250             // than the DEBUG versions as these generally generate too much logging for our purposes.
 251             // However we do want the DEBUG versions of our Moodle-specific modules.
 252             // To debug a YUI-specific issue, change the yui3loader->filter value to DEBUG.
 253             $this->YUI_config->filter = 'RAW';
 254             $this->YUI_config->groups['moodle']['filter'] = 'DEBUG';
 255
 256             // We use the yui3loader->filter setting when writing the YUI3 seed scripts into the header.
 257             $this->yui3loader->filter = $this->YUI_config->filter;
 258             $this->YUI_config->debug = true;
 259         } else {
 260             $this->yui3loader->filter = null;
 261             $this->YUI_config->groups['moodle']['filter'] = null;
 262             $this->YUI_config->debug = false;
 263         }
 264
 265         // Include the YUI config log filters.
 266         if (!empty($CFG->yuilogexclude) && is_array($CFG->yuilogexclude)) {
 267             $this->YUI_config->logExclude = $CFG->yuilogexclude;
 268         }
 269         if (!empty($CFG->yuiloginclude) && is_array($CFG->yuiloginclude)) {
 270             $this->YUI_config->logInclude = $CFG->yuiloginclude;
 271         }
 272         if (!empty($CFG->yuiloglevel)) {
 273             $this->YUI_config->logLevel = $CFG->yuiloglevel;
 274         }
 275
 276         // Add the moodle group's module data.
 277         $this->YUI_config->add_moodle_metadata();
 278
 279         // Every page should include definition of following modules.
 280         $this->js_module($this->find_module('core_filepicker'));
 281     }
 282
 283     /**
 284      * Initialise with the bits of JavaScript that every Moodle page should have.
 285      *
 286      * @param moodle_page $page
 287      * @param core_renderer $renderer
 288      */
 289     protected function init_requirements_data(moodle_page $page, core_renderer $renderer) {
 290         global $CFG;
 291
 292         // JavaScript should always work with $CFG->httpswwwroot rather than $CFG->wwwroot.
 293         // Otherwise, in some situations, users will get warnings about insecure content
 294         // on secure pages from their web browser.
 295
 296         $this->M_cfg = array(
 297             'wwwroot'             => $CFG->httpswwwroot, // Yes, really. See above.
 298             'sesskey'             => sesskey(),
 299             'loadingicon'         => $renderer->pix_url('i/loading_small', 'moodle')->out(false),
 300             'themerev'            => theme_get_revision(),
 301             'slasharguments'      => (int)(!empty($CFG->slasharguments)),
 302             'theme'               => $page->theme->name,
 303             'jsrev'               => $this->get_jsrev(),
 304             'svgicons'            => $page->theme->use_svg_icons()
 305         );
 306         if ($CFG->debugdeveloper) {
 307             $this->M_cfg['developerdebug'] = true;
 308         }
 309         if (defined('BEHAT_SITE_RUNNING')) {
 310             $this->M_cfg['behatsiterunning'] = true;
 311         }
 312
 313         // Accessibility stuff.
 314         $this->skip_link_to('maincontent', get_string('tocontent', 'access'));
 315
 316         // Add strings used on many pages.
 317         $this->string_for_js('confirmation', 'admin');
 318         $this->string_for_js('cancel', 'moodle');
 319         $this->string_for_js('yes', 'moodle');
 320
 321         // Alter links in top frame to break out of frames.
 322         if ($page->pagelayout === 'frametop') {
 323             $this->js_init_call('M.util.init_frametop');
 324         }
 325
 326         // Include block drag/drop if editing is on
 327         if ($page->user_is_editing()) {
 328             $params = array(
 329                 'courseid' => $page->course->id,
 330                 'pagetype' => $page->pagetype,
 331                 'pagelayout' => $page->pagelayout,
 332                 'subpage' => $page->subpage,
 333                 'regions' => $page->blocks->get_regions(),
 334                 'contextid' => $page->context->id,
 335             );
 336             if (!empty($page->cm->id)) {
 337                 $params['cmid'] = $page->cm->id;
 338             }
 339             // Strings for drag and drop.
 340             $this->strings_for_js(array('movecontent',
 341                                         'tocontent',
 342                                         'emptydragdropregion'),
 343                                   'moodle');
 344             $page->requires->yui_module('moodle-core-blocks', 'M.core_blocks.init_dragdrop', array($params), null, true);
 345         }
 346     }
 347
 348     /**
 349      * Determine the correct JS Revision to use for this load.
 350      *
 351      * @return int the jsrev to use.
 352      */
 353     protected function get_jsrev() {
 354         global $CFG;
 355
 356         if (empty($CFG->cachejs)) {
 357             $jsrev = -1;
 358         } else if (empty($CFG->jsrev)) {
 359             $jsrev = 1;
 360         } else {
 361             $jsrev = $CFG->jsrev;
 362         }
 363
 364         return $jsrev;
 365     }
 366
 367     /**
 368      * Ensure that the specified JavaScript file is linked to from this page.
 369      *
 370      * NOTE: This function is to be used in RARE CASES ONLY, please store your JS in module.js file
 371      * and use $PAGE->requires->js_init_call() instead or use /yui/ subdirectories for YUI modules.
 372      *
 373      * By default the link is put at the end of the page, since this gives best page-load performance.
 374      *
 375      * Even if a particular script is requested more than once, it will only be linked
 376      * to once.
 377      *
 378      * @param string|moodle_url $url The path to the .js file, relative to $CFG->dirroot / $CFG->wwwroot.
 379      *      For example '/mod/mymod/customscripts.js'; use moodle_url for external scripts
 380      * @param bool $inhead initialise in head
 381      */
 382     public function js($url, $inhead = false) {
 383         $url = $this->js_fix_url($url);
 384         $where = $inhead ? 'head' : 'footer';
 385         $this->jsincludes[$where][$url->out()] = $url;
 386     }
 387
 388     /**
 389      * Request inclusion of jQuery library in the page.
 390      *
 391      * NOTE: this should not be used in official Moodle distribution!
 392      *
 393      * We are going to bundle jQuery 1.9.x until we drop support
 394      * all support for IE 6-8. Use $PAGE->requires->jquery_plugin('migrate')
 395      * for code written for earlier jQuery versions.
 396      *
 397      * {@see http://docs.moodle.org/dev/jQuery}
 398      */
 399     public function jquery() {
 400         $this->jquery_plugin('jquery');
 401     }
 402
 403     /**
 404      * Request inclusion of jQuery plugin.
 405      *
 406      * NOTE: this should not be used in official Moodle distribution!
 407      *
 408      * jQuery plugins are located in plugin/jquery/* subdirectory,
 409      * plugin/jquery/plugins.php lists all available plugins.
 410      *
 411      * Included core plugins:
 412      *   - jQuery UI
 413      *   - jQuery Migrate (useful for code written for previous UI version)
 414      *
 415      * Add-ons may include extra jQuery plugins in jquery/ directory,
 416      * plugins.php file defines the mapping between plugin names and
 417      * necessary page includes.
 418      *
 419      * Examples:
 420      * <code>
 421      *   // file: mod/xxx/view.php
 422      *   $PAGE->requires->jquery();
 423      *   $PAGE->requires->jquery_plugin('ui');
 424      *   $PAGE->requires->jquery_plugin('ui-css');
 425      * </code>
 426      *
 427      * <code>
 428      *   // file: theme/yyy/lib.php
 429      *   function theme_yyy_page_init(moodle_page $page) {
 430      *       $page->requires->jquery();
 431      *       $page->requires->jquery_plugin('ui');
 432      *       $page->requires->jquery_plugin('ui-css');
 433      *   }
 434      * </code>
 435      *
 436      * <code>
 437      *   // file: blocks/zzz/block_zzz.php
 438      *   public function get_required_javascript() {
 439      *       parent::get_required_javascript();
 440      *       $this->page->requires->jquery();
 441      *       $page->requires->jquery_plugin('ui');
 442      *       $page->requires->jquery_plugin('ui-css');
 443      *   }
 444      * </code>
 445      *
 446      * {@see http://docs.moodle.org/dev/jQuery}
 447      *
 448      * @param string $plugin name of the jQuery plugin as defined in jquery/plugins.php
 449      * @param string $component name of the component
 450      * @return bool success
 451      */
 452     public function jquery_plugin($plugin, $component = 'core') {
 453         global $CFG;
 454
 455         if ($this->headdone) {
 456             debugging('Can not add jQuery plugins after starting page output!');
 457             return false;
 458         }
 459
 460         if ($component !== 'core' and in_array($plugin, array('jquery', 'ui', 'ui-css', 'migrate'))) {
 461             debugging("jQuery plugin '$plugin' is included in Moodle core, other components can not use the same name.", DEBUG_DEVELOPER);
 462             $component = 'core';
 463         } else if ($component !== 'core' and strpos($component, '_') === false) {
 464             // Let's normalise the legacy activity names, Frankenstyle rulez!
 465             $component = 'mod_' . $component;
 466         }
 467
 468         if (empty($this->jqueryplugins) and ($component !== 'core' or $plugin !== 'jquery')) {
 469             // Make sure the jQuery itself is always loaded first,
 470             // the order of all other plugins depends on order of $PAGE_>requires->.
 471             $this->jquery_plugin('jquery', 'core');
 472         }
 473
 474         if (isset($this->jqueryplugins[$plugin])) {
 475             // No problem, we already have something, first Moodle plugin to register the jQuery plugin wins.
 476             return true;
 477         }
 478
 479         $componentdir = core_component::get_component_directory($component);
 480         if (!file_exists($componentdir) or !file_exists("$componentdir/jquery/plugins.php")) {
 481             debugging("Can not load jQuery plugin '$plugin', missing plugins.php in component '$component'.", DEBUG_DEVELOPER);
 482             return false;
 483         }
 484
 485         $plugins = array();
 486         require("$componentdir/jquery/plugins.php");
 487
 488         if (!isset($plugins[$plugin])) {
 489             debugging("jQuery plugin '$plugin' can not be found in component '$component'.", DEBUG_DEVELOPER);
 490             return false;
 491         }
 492
 493         $this->jqueryplugins[$plugin] = new stdClass();
 494         $this->jqueryplugins[$plugin]->plugin    = $plugin;
 495         $this->jqueryplugins[$plugin]->component = $component;
 496         $this->jqueryplugins[$plugin]->urls      = array();
 497
 498         foreach ($plugins[$plugin]['files'] as $file) {
 499             if ($CFG->debugdeveloper) {
 500                 if (!file_exists("$componentdir/jquery/$file")) {
 501                     debugging("Invalid file '$file' specified in jQuery plugin '$plugin' in component '$component'");
 502                     continue;
 503                 }
 504                 $file = str_replace('.min.css', '.css', $file);
 505                 $file = str_replace('.min.js', '.js', $file);
 506             }
 507             if (!file_exists("$componentdir/jquery/$file")) {
 508                 debugging("Invalid file '$file' specified in jQuery plugin '$plugin' in component '$component'");
 509                 continue;
 510             }
 511             if (!empty($CFG->slasharguments)) {
 512                 $url = new moodle_url("$CFG->httpswwwroot/theme/jquery.php");
 513                 $url->set_slashargument("/$component/$file");
 514
 515             } else {
 516                 // This is not really good, we need slasharguments for relative links, this means no caching...
 517                 $path = realpath("$componentdir/jquery/$file");
 518                 if (strpos($path, $CFG->dirroot) === 0) {
 519                     $url = $CFG->httpswwwroot.preg_replace('/^'.preg_quote($CFG->dirroot, '/').'/', '', $path);
 520                     $url = new moodle_url($url);
 521                 } else {
 522                     // Bad luck, fix your server!
 523                     debugging("Moodle jQuery integration requires 'slasharguments' setting to be enabled.");
 524                     continue;
 525                 }
 526             }
 527             $this->jqueryplugins[$plugin]->urls[] = $url;
 528         }
 529
 530         return true;
 531     }
 532
 533     /**
 534      * Request replacement of one jQuery plugin by another.
 535      *
 536      * This is useful when themes want to replace the jQuery UI theme,
 537      * the problem is that theme can not prevent others from including the core ui-css plugin.
 538      *
 539      * Example:
 540      *  1/ generate new jQuery UI theme and place it into theme/yourtheme/jquery/
 541      *  2/ write theme/yourtheme/jquery/plugins.php
 542      *  3/ init jQuery from theme
 543      *
 544      * <code>
 545      *   // file theme/yourtheme/lib.php
 546      *   function theme_yourtheme_page_init($page) {
 547      *       $page->requires->jquery_plugin('yourtheme-ui-css', 'theme_yourtheme');
 548      *       $page->requires->jquery_override_plugin('ui-css', 'yourtheme-ui-css');
 549      *   }
 550      * </code>
 551      *
 552      * This code prevents loading of standard 'ui-css' which my be requested by other plugins,
 553      * the 'yourtheme-ui-css' gets loaded only if some other code requires jquery.
 554      *
 555      * {@see http://docs.moodle.org/dev/jQuery}
 556      *
 557      * @param string $oldplugin original plugin
 558      * @param string $newplugin the replacement
 559      */
 560     public function jquery_override_plugin($oldplugin, $newplugin) {
 561         if ($this->headdone) {
 562             debugging('Can not override jQuery plugins after starting page output!');
 563             return;
 564         }
 565         $this->jquerypluginoverrides[$oldplugin] = $newplugin;
 566     }
 567
 568     /**
 569      * Return jQuery related markup for page start.
 570      * @return string
 571      */
 572     protected function get_jquery_headcode() {
 573         if (empty($this->jqueryplugins['jquery'])) {
 574             // If nobody requested jQuery then do not bother to load anything.
 575             // This may be useful for themes that want to override 'ui-css' only if requested by something else.
 576             return '';
 577         }
 578
 579         $included = array();
 580         $urls = array();
 581
 582         foreach ($this->jqueryplugins as $name => $unused) {
 583             if (isset($included[$name])) {
 584                 continue;
 585             }
 586             if (array_key_exists($name, $this->jquerypluginoverrides)) {
 587                 // The following loop tries to resolve the replacements,
 588                 // use max 100 iterations to prevent infinite loop resulting
 589                 // in blank page.
 590                 $cyclic = true;
 591                 $oldname = $name;
 592                 for ($i=0; $i<100; $i++) {
 593                     $name = $this->jquerypluginoverrides[$name];
 594                     if (!array_key_exists($name, $this->jquerypluginoverrides)) {
 595                         $cyclic = false;
 596                         break;
 597                     }
 598                 }
 599                 if ($cyclic) {
 600                     // We can not do much with cyclic references here, let's use the old plugin.
 601                     $name = $oldname;
 602                     debugging("Cyclic overrides detected for jQuery plugin '$name'");
 603
 604                 } else if (empty($name)) {
 605                     // Developer requested removal of the plugin.
 606                     continue;
 607
 608                 } else if (!isset($this->jqueryplugins[$name])) {
 609                     debugging("Unknown jQuery override plugin '$name' detected");
 610                     $name = $oldname;
 611
 612                 } else if (isset($included[$name])) {
 613                     // The plugin was already included, easy.
 614                     continue;
 615                 }
 616             }
 617
 618             $plugin = $this->jqueryplugins[$name];
 619             $urls = array_merge($urls, $plugin->urls);
 620             $included[$name] = true;
 621         }
 622
 623         $output = '';
 624         $attributes = array('rel' => 'stylesheet', 'type' => 'text/css');
 625         foreach ($urls as $url) {
 626             if (preg_match('/\.js$/', $url)) {
 627                 $output .= html_writer::script('', $url);
 628             } else if (preg_match('/\.css$/', $url)) {
 629                 $attributes['href'] = $url;
 630                 $output .= html_writer::empty_tag('link', $attributes) . "\n";
 631             }
 632         }
 633
 634         return $output;
 635     }
 636
 637     /**
 638      * Returns the actual url through which a script is served.
 639      *
 640      * @param moodle_url|string $url full moodle url, or shortened path to script
 641      * @return moodle_url
 642      */
 643     protected function js_fix_url($url) {
 644         global $CFG;
 645
 646         if ($url instanceof moodle_url) {
 647             return $url;
 648         } else if (strpos($url, '/') === 0) {
 649             // Fix the admin links if needed.
 650             if ($CFG->admin !== 'admin') {
 651                 if (strpos($url, "/admin/") === 0) {
 652                     $url = preg_replace("|^/admin/|", "/$CFG->admin/", $url);
 653                 }
 654             }
 655             if (debugging()) {
 656                 // Check file existence only when in debug mode.
 657                 if (!file_exists($CFG->dirroot . strtok($url, '?'))) {
 658                     throw new coding_exception('Attempt to require a JavaScript file that does not exist.', $url);
 659                 }
 660             }
 661             if (substr($url, -3) === '.js') {
 662                 $jsrev = $this->get_jsrev();
 663                 if (empty($CFG->slasharguments)) {
 664                     return new moodle_url($CFG->httpswwwroot.'/lib/javascript.php', array('rev'=>$jsrev, 'jsfile'=>$url));
 665                 } else {
 666                     $returnurl = new moodle_url($CFG->httpswwwroot.'/lib/javascript.php');
 667                     $returnurl->set_slashargument('/'.$jsrev.$url);
 668                     return $returnurl;
 669                 }
 670             } else {
 671                 return new moodle_url($CFG->httpswwwroot.$url);
 672             }
 673         } else {
 674             throw new coding_exception('Invalid JS url, it has to be shortened url starting with / or moodle_url instance.', $url);
 675         }
 676     }
 677
 678     /**
 679      * Find out if JS module present and return details.
 680      *
 681      * @param string $component name of component in frankenstyle, ex: core_group, mod_forum
 682      * @return array description of module or null if not found
 683      */
 684     protected function find_module($component) {
 685         global $CFG, $PAGE;
 686
 687         $module = null;
 688
 689         if (strpos($component, 'core_') === 0) {
 690             // Must be some core stuff - list here is not complete, this is just the stuff used from multiple places
 691             // so that we do nto have to repeat the definition of these modules over and over again.
 692             switch($component) {
 693                 case 'core_filepicker':
 694                     $module = array('name'     => 'core_filepicker',
 695                                     'fullpath' => '/repository/filepicker.js',
 696                                     'requires' => array('base', 'node', 'node-event-simulate', 'json', 'async-queue', 'io-base', 'io-upload-iframe', 'io-form', 'yui2-treeview', 'panel', 'cookie', 'datatable', 'datatable-sort', 'resize-plugin', 'dd-plugin', 'escape', 'moodle-core_filepicker'),
 697                                     'strings'  => array(array('lastmodified', 'moodle'), array('name', 'moodle'), array('type', 'repository'), array('size', 'repository'),
 698                                                         array('invalidjson', 'repository'), array('error', 'moodle'), array('info', 'moodle'),
 699                                                         array('nofilesattached', 'repository'), array('filepicker', 'repository'), array('logout', 'repository'),
 700                                                         array('nofilesavailable', 'repository'), array('norepositoriesavailable', 'repository'),
 701                                                         array('fileexistsdialogheader', 'repository'), array('fileexistsdialog_editor', 'repository'),
 702                                                         array('fileexistsdialog_filemanager', 'repository'), array('renameto', 'repository'),
 703                                                         array('referencesexist', 'repository'), array('select', 'repository')
 704                                                     ));
 705                     break;
 706                 case 'core_comment':
 707                     $module = array('name'     => 'core_comment',
 708                                     'fullpath' => '/comment/comment.js',
 709                                     'requires' => array('base', 'io-base', 'node', 'json', 'yui2-animation', 'overlay'),
 710                                     'strings' => array(array('confirmdeletecomments', 'admin'), array('yes', 'moodle'), array('no', 'moodle'))
 711                                 );
 712                     break;
 713                 case 'core_role':
 714                     $module = array('name'     => 'core_role',
 715                                     'fullpath' => '/admin/roles/module.js',
 716                                     'requires' => array('node', 'cookie'));
 717                     break;
 718                 case 'core_completion':
 719                     $module = array('name'     => 'core_completion',
 720                                     'fullpath' => '/course/completion.js');
 721                     break;
 722                 case 'core_message':
 723                     $module = array('name'     => 'core_message',
 724                                     'requires' => array('base', 'node', 'event', 'node-event-simulate'),
 725                                     'fullpath' => '/message/module.js');
 726                     break;
 727                 case 'core_group':
 728                     $module = array('name'     => 'core_group',
 729                                     'fullpath' => '/group/module.js',
 730                                     'requires' => array('node', 'overlay', 'event-mouseenter'));
 731                     break;
 732                 case 'core_question_engine':
 733                     $module = array('name'     => 'core_question_engine',
 734                                     'fullpath' => '/question/qengine.js',
 735                                     'requires' => array('node', 'event'));
 736                     break;
 737                 case 'core_rating':
 738                     $module = array('name'     => 'core_rating',
 739                                     'fullpath' => '/rating/module.js',
 740                                     'requires' => array('node', 'event', 'overlay', 'io-base', 'json'));
 741                     break;
 742                 case 'core_dndupload':
 743                     $module = array('name'     => 'core_dndupload',
 744                                     'fullpath' => '/lib/form/dndupload.js',
 745                                     'requires' => array('node', 'event', 'json', 'core_filepicker'),
 746                                     'strings'  => array(array('uploadformlimit', 'moodle'), array('droptoupload', 'moodle'), array('maxfilesreached', 'moodle'),
 747                                                         array('dndenabled_inbox', 'moodle'), array('fileexists', 'moodle'), array('maxbytesforfile', 'moodle'),
 748                                                         array('maxareabytesreached', 'moodle'), array('serverconnection', 'error'),
 749                                                     ));
 750                     break;
 751             }
 752
 753         } else {
 754             if ($dir = core_component::get_component_directory($component)) {
 755                 if (file_exists("$dir/module.js")) {
 756                     if (strpos($dir, $CFG->dirroot.'/') === 0) {
 757                         $dir = substr($dir, strlen($CFG->dirroot));
 758                         $module = array('name'=>$component, 'fullpath'=>"$dir/module.js", 'requires' => array());
 759                     }
 760                 }
 761             }
 762         }
 763
 764         return $module;
 765     }
 766
 767     /**
 768      * Append YUI3 module to default YUI3 JS loader.
 769      * The structure of module array is described at {@link http://developer.yahoo.com/yui/3/yui/}
 770      *
 771      * @param string|array $module name of module (details are autodetected), or full module specification as array
 772      * @return void
 773      */
 774     public function js_module($module) {
 775         global $CFG;
 776
 777         if (empty($module)) {
 778             throw new coding_exception('Missing YUI3 module name or full description.');
 779         }
 780
 781         if (is_string($module)) {
 782             $module = $this->find_module($module);
 783         }
 784
 785         if (empty($module) or empty($module['name']) or empty($module['fullpath'])) {
 786             throw new coding_exception('Missing YUI3 module details.');
 787         }
 788
 789         $module['fullpath'] = $this->js_fix_url($module['fullpath'])->out(false);
 790         // Add all needed strings.
 791         if (!empty($module['strings'])) {
 792             foreach ($module['strings'] as $string) {
 793                 $identifier = $string[0];
 794                 $component = isset($string[1]) ? $string[1] : 'moodle';
 795                 $a = isset($string[2]) ? $string[2] : null;
 796                 $this->string_for_js($identifier, $component, $a);
 797             }
 798         }
 799         unset($module['strings']);
 800
 801         // Process module requirements and attempt to load each. This allows
 802         // moodle modules to require each other.
 803         if (!empty($module['requires'])){
 804             foreach ($module['requires'] as $requirement) {
 805                 $rmodule = $this->find_module($requirement);
 806                 if (is_array($rmodule)) {
 807                     $this->js_module($rmodule);
 808                 }
 809             }
 810         }
 811
 812         if ($this->headdone) {
 813             $this->extramodules[$module['name']] = $module;
 814         } else {
 815             $this->YUI_config->add_module_config($module['name'], $module);
 816         }
 817     }
 818
 819     /**
 820      * Returns true if the module has already been loaded.
 821      *
 822      * @param string|array $module
 823      * @return bool True if the module has already been loaded
 824      */
 825     protected function js_module_loaded($module) {
 826         if (is_string($module)) {
 827             $modulename = $module;
 828         } else {
 829             $modulename = $module['name'];
 830         }
 831         return array_key_exists($modulename, $this->YUI_config->modules) ||
 832                array_key_exists($modulename, $this->extramodules);
 833     }
 834
 835     /**
 836      * Ensure that the specified CSS file is linked to from this page.
 837      *
 838      * Because stylesheet links must go in the <head> part of the HTML, you must call
 839      * this function before {@link get_head_code()} is called. That normally means before
 840      * the call to print_header. If you call it when it is too late, an exception
 841      * will be thrown.
 842      *
 843      * Even if a particular style sheet is requested more than once, it will only
 844      * be linked to once.
 845      *
 846      * Please note use of this feature is strongly discouraged,
 847      * it is suitable only for places where CSS is submitted directly by teachers.
 848      * (Students must not be allowed to submit any external CSS because it may
 849      * contain embedded javascript!). Example of correct use is mod/data.
 850      *
 851      * @param string $stylesheet The path to the .css file, relative to $CFG->wwwroot.
 852      *   For example:
 853      *      $PAGE->requires->css('mod/data/css.php?d='.$data->id);
 854      */
 855     public function css($stylesheet) {
 856         global $CFG;
 857
 858         if ($this->headdone) {
 859             throw new coding_exception('Cannot require a CSS file after &lt;head> has been printed.', $stylesheet);
 860         }
 861
 862         if ($stylesheet instanceof moodle_url) {
 863             // ok
 864         } else if (strpos($stylesheet, '/') === 0) {
 865             $stylesheet = new moodle_url($CFG->httpswwwroot.$stylesheet);
 866         } else {
 867             throw new coding_exception('Invalid stylesheet parameter.', $stylesheet);
 868         }
 869
 870         $this->cssurls[$stylesheet->out()] = $stylesheet;
 871     }
 872
 873     /**
 874      * Add theme stylesheet to page - do not use from plugin code,
 875      * this should be called only from the core renderer!
 876      *
 877      * @param moodle_url $stylesheet
 878      * @return void
 879      */
 880     public function css_theme(moodle_url $stylesheet) {
 881         $this->cssthemeurls[] = $stylesheet;
 882     }
 883
 884     /**
 885      * Ensure that a skip link to a given target is printed at the top of the <body>.
 886      *
 887      * You must call this function before {@link get_top_of_body_code()}, (if not, an exception
 888      * will be thrown). That normally means you must call this before the call to print_header.
 889      *
 890      * If you ask for a particular skip link to be printed, it is then your responsibility
 891      * to ensure that the appropriate <a name="..."> tag is printed in the body of the
 892      * page, so that the skip link goes somewhere.
 893      *
 894      * Even if a particular skip link is requested more than once, only one copy of it will be output.
 895      *
 896      * @param string $target the name of anchor this link should go to. For example 'maincontent'.
 897      * @param string $linktext The text to use for the skip link. Normally get_string('skipto', 'access', ...);
 898      */
 899     public function skip_link_to($target, $linktext) {
 900         if ($this->topofbodydone) {
 901             debugging('Page header already printed, can not add skip links any more, code needs to be fixed.');
 902             return;
 903         }
 904         $this->skiplinks[$target] = $linktext;
 905     }
 906
 907     /**
 908      * !!!DEPRECATED!!! please use js_init_call() if possible
 909      * Ensure that the specified JavaScript function is called from an inline script
 910      * somewhere on this page.
 911      *
 912      * By default the call will be put in a script tag at the
 913      * end of the page after initialising Y instance, since this gives best page-load
 914      * performance and allows you to use YUI3 library.
 915      *
 916      * If you request that a particular function is called several times, then
 917      * that is what will happen (unlike linking to a CSS or JS file, where only
 918      * one link will be output).
 919      *
 920      * The main benefit of the method is the automatic encoding of all function parameters.
 921      *
 922      * @deprecated
 923      *
 924      * @param string $function the name of the JavaScritp function to call. Can
 925      *      be a compound name like 'Y.Event.purgeElement'. Can also be
 926      *      used to create and object by using a 'function name' like 'new user_selector'.
 927      * @param array $arguments and array of arguments to be passed to the function.
 928      *      When generating the function call, this will be escaped using json_encode,
 929      *      so passing objects and arrays should work.
 930      * @param bool $ondomready If tru the function is only called when the dom is
 931      *      ready for manipulation.
 932      * @param int $delay The delay before the function is called.
 933      */
 934     public function js_function_call($function, array $arguments = null, $ondomready = false, $delay = 0) {
 935         $where = $ondomready ? 'ondomready' : 'normal';
 936         $this->jscalls[$where][] = array($function, $arguments, $delay);
 937     }
 938
 939     /**
 940      * Creates a JavaScript function call that requires one or more modules to be loaded.
 941      *
 942      * This function can be used to include all of the standard YUI module types within JavaScript:
 943      *     - YUI3 modules    [node, event, io]
 944      *     - YUI2 modules    [yui2-*]
 945      *     - Moodle modules  [moodle-*]
 946      *     - Gallery modules [gallery-*]
 947      *
 948      * @param array|string $modules One or more modules
 949      * @param string $function The function to call once modules have been loaded
 950      * @param array $arguments An array of arguments to pass to the function
 951      * @param string $galleryversion Deprecated: The gallery version to use
 952      * @param bool $ondomready
 953      */
 954     public function yui_module($modules, $function, array $arguments = null, $galleryversion = null, $ondomready = false) {
 955         if (!is_array($modules)) {
 956             $modules = array($modules);
 957         }
 958
 959         if ($galleryversion != null) {
 960             debugging('The galleryversion parameter to yui_module has been deprecated since Moodle 2.3.');
 961         }
 962
 963         $jscode = 'Y.use('.join(',', array_map('json_encode', convert_to_array($modules))).',function() {'.js_writer::function_call($function, $arguments).'});';
 964         if ($ondomready) {
 965             $jscode = "Y.on('domready', function() { $jscode });";
 966         }
 967         $this->jsinitcode[] = $jscode;
 968     }
 969
 970     /**
 971      * Ensure that the specified JavaScript function is called from an inline script
 972      * from page footer.
 973      *
 974      * @param string $function the name of the JavaScritp function to with init code,
 975      *      usually something like 'M.mod_mymodule.init'
 976      * @param array $extraarguments and array of arguments to be passed to the function.
 977      *      The first argument is always the YUI3 Y instance with all required dependencies
 978      *      already loaded.
 979      * @param bool $ondomready wait for dom ready (helps with some IE problems when modifying DOM)
 980      * @param array $module JS module specification array
 981      */
 982     public function js_init_call($function, array $extraarguments = null, $ondomready = false, array $module = null) {
 983         $jscode = js_writer::function_call_with_Y($function, $extraarguments);
 984         if (!$module) {
 985             // Detect module automatically.
 986             if (preg_match('/M\.([a-z0-9]+_[^\.]+)/', $function, $matches)) {
 987                 $module = $this->find_module($matches[1]);
 988             }
 989         }
 990
 991         $this->js_init_code($jscode, $ondomready, $module);
 992     }
 993
 994     /**
 995      * Add short static javascript code fragment to page footer.
 996      * This is intended primarily for loading of js modules and initialising page layout.
 997      * Ideally the JS code fragment should be stored in plugin renderer so that themes
 998      * may override it.
 999      *
1000      * @param string $jscode
1001      * @param bool $ondomready wait for dom ready (helps with some IE problems when modifying DOM)
1002      * @param array $module JS module specification array
1003      */
1004     public function js_init_code($jscode, $ondomready = false, array $module = null) {
1005         $jscode = trim($jscode, " ;\n"). ';';
1006
1007         $uniqid = html_writer::random_id();
1008         $startjs = " M.util.js_pending('" . $uniqid . "');";
1009         $endjs = " M.util.js_complete('" . $uniqid . "');";
1010
1011         if ($module) {
1012             $this->js_module($module);
1013             $modulename = $module['name'];
1014             $jscode = "$startjs Y.use('$modulename', function(Y) { $jscode $endjs });";
1015         }
1016
1017         if ($ondomready) {
1018             $jscode = "$startjs Y.on('domready', function() { $jscode $endjs });";
1019         }
1020
1021         $this->jsinitcode[] = $jscode;
1022     }
1023
1024     /**
1025      * Make a language string available to JavaScript.
1026      *
1027      * All the strings will be available in a M.str object in the global namespace.
1028      * So, for example, after a call to $PAGE->requires->string_for_js('course', 'moodle');
1029      * then the JavaScript variable M.str.moodle.course will be 'Course', or the
1030      * equivalent in the current language.
1031      *
1032      * The arguments to this function are just like the arguments to get_string
1033      * except that $component is not optional, and there are some aspects to consider
1034      * when the string contains {$a} placeholder.
1035      *
1036      * If the string does not contain any {$a} placeholder, you can simply use
1037      * M.str.component.identifier to obtain it. If you prefer, you can call
1038      * M.util.get_string(identifier, component) to get the same result.
1039      *
1040      * If you need to use {$a} placeholders, there are two options. Either the
1041      * placeholder should be substituted in PHP on server side or it should
1042      * be substituted in Javascript at client side.
1043      *
1044      * To substitute the placeholder at server side, just provide the required
1045      * value for the placeholder when you require the string. Because each string
1046      * is only stored once in the JavaScript (based on $identifier and $module)
1047      * you cannot get the same string with two different values of $a. If you try,
1048      * an exception will be thrown. Once the placeholder is substituted, you can
1049      * use M.str or M.util.get_string() as shown above:
1050      *
1051      *     // Require the string in PHP and replace the placeholder.
1052      *     $PAGE->requires->string_for_js('fullnamedisplay', 'moodle', $USER);
1053      *     // Use the result of the substitution in Javascript.
1054      *     alert(M.str.moodle.fullnamedisplay);
1055      *
1056      * To substitute the placeholder at client side, use M.util.get_string()
1057      * function. It implements the same logic as {@link get_string()}:
1058      *
1059      *     // Require the string in PHP but keep {$a} as it is.
1060      *     $PAGE->requires->string_for_js('fullnamedisplay', 'moodle');
1061      *     // Provide the values on the fly in Javascript.
1062      *     user = { firstname : 'Harry', lastname : 'Potter' }
1063      *     alert(M.util.get_string('fullnamedisplay', 'moodle', user);
1064      *
1065      * If you do need the same string expanded with different $a values in PHP
1066      * on server side, then the solution is to put them in your own data structure
1067      * (e.g. and array) that you pass to JavaScript with {@link data_for_js()}.
1068      *
1069      * @param string $identifier the desired string.
1070      * @param string $component the language file to look in.
1071      * @param mixed $a any extra data to add into the string (optional).
1072      */
1073     public function string_for_js($identifier, $component, $a = null) {
1074         if (!$component) {
1075             throw new coding_exception('The $component parameter is required for page_requirements_manager::string_for_js().');
1076         }
1077         if (isset($this->stringsforjs_as[$component][$identifier]) and $this->stringsforjs_as[$component][$identifier] !== $a) {
1078             throw new coding_exception("Attempt to re-define already required string '$identifier' " .
1079                     "from lang file '$component' with different \$a parameter?");
1080         }
1081         if (!isset($this->stringsforjs[$component][$identifier])) {
1082             $this->stringsforjs[$component][$identifier] = new lang_string($identifier, $component, $a);
1083             $this->stringsforjs_as[$component][$identifier] = $a;
1084         }
1085     }
1086
1087     /**
1088      * Make an array of language strings available for JS.
1089      *
1090      * This function calls the above function {@link string_for_js()} for each requested
1091      * string in the $identifiers array that is passed to the argument for a single module
1092      * passed in $module.
1093      *
1094      * <code>
1095      * $PAGE->requires->strings_for_js(array('one', 'two', 'three'), 'mymod', array('a', null, 3));
1096      *
1097      * // The above is identical to calling:
1098      *
1099      * $PAGE->requires->string_for_js('one', 'mymod', 'a');
1100      * $PAGE->requires->string_for_js('two', 'mymod');
1101      * $PAGE->requires->string_for_js('three', 'mymod', 3);
1102      * </code>
1103      *
1104      * @param array $identifiers An array of desired strings
1105      * @param string $component The module to load for
1106      * @param mixed $a This can either be a single variable that gets passed as extra
1107      *         information for every string or it can be an array of mixed data where the
1108      *         key for the data matches that of the identifier it is meant for.
1109      *
1110      */
1111     public function strings_for_js($identifiers, $component, $a = null) {
1112         foreach ($identifiers as $key => $identifier) {
1113             if (is_array($a) && array_key_exists($key, $a)) {
1114                 $extra = $a[$key];
1115             } else {
1116                 $extra = $a;
1117             }
1118             $this->string_for_js($identifier, $component, $extra);
1119         }
1120     }
1121
1122     /**
1123      * !!!!!!DEPRECATED!!!!!! please use js_init_call() for everything now.
1124      *
1125      * Make some data from PHP available to JavaScript code.
1126      *
1127      * For example, if you call
1128      * <pre>
1129      *      $PAGE->requires->data_for_js('mydata', array('name' => 'Moodle'));
1130      * </pre>
1131      * then in JavsScript mydata.name will be 'Moodle'.
1132      *
1133      * @deprecated
1134      * @param string $variable the the name of the JavaScript variable to assign the data to.
1135      *      Will probably work if you use a compound name like 'mybuttons.button[1]', but this
1136      *      should be considered an experimental feature.
1137      * @param mixed $data The data to pass to JavaScript. This will be escaped using json_encode,
1138      *      so passing objects and arrays should work.
1139      * @param bool $inhead initialise in head
1140      * @return void
1141      */
1142     public function data_for_js($variable, $data, $inhead=false) {
1143         $where = $inhead ? 'head' : 'footer';
1144         $this->jsinitvariables[$where][] = array($variable, $data);
1145     }
1146
1147     /**
1148      * Creates a YUI event handler.
1149      *
1150      * @param mixed $selector standard YUI selector for elements, may be array or string, element id is in the form "#idvalue"
1151      * @param string $event A valid DOM event (click, mousedown, change etc.)
1152      * @param string $function The name of the function to call
1153      * @param array  $arguments An optional array of argument parameters to pass to the function
1154      */
1155     public function event_handler($selector, $event, $function, array $arguments = null) {
1156         $this->eventhandlers[] = array('selector'=>$selector, 'event'=>$event, 'function'=>$function, 'arguments'=>$arguments);
1157     }
1158
1159     /**
1160      * Returns code needed for registering of event handlers.
1161      * @return string JS code
1162      */
1163     protected function get_event_handler_code() {
1164         $output = '';
1165         foreach ($this->eventhandlers as $h) {
1166             $output .= js_writer::event_handler($h['selector'], $h['event'], $h['function'], $h['arguments']);
1167         }
1168         return $output;
1169     }
1170
1171     /**
1172      * Get the inline JavaScript code that need to appear in a particular place.
1173      * @param bool $ondomready
1174      * @return string
1175      */
1176     protected function get_javascript_code($ondomready) {
1177         $where = $ondomready ? 'ondomready' : 'normal';
1178         $output = '';
1179         if ($this->jscalls[$where]) {
1180             foreach ($this->jscalls[$where] as $data) {
1181                 $output .= js_writer::function_call($data[0], $data[1], $data[2]);
1182             }
1183             if (!empty($ondomready)) {
1184                 $output = "    Y.on('domready', function() {\n$output\n});";
1185             }
1186         }
1187         return $output;
1188     }
1189
1190     /**
1191      * Returns js code to be executed when Y is available.
1192      * @return string
1193      */
1194     protected function get_javascript_init_code() {
1195         if (count($this->jsinitcode)) {
1196             return implode("\n", $this->jsinitcode) . "\n";
1197         }
1198         return '';
1199     }
1200
1201     /**
1202      * Returns basic YUI3 JS loading code.
1203      * YUI3 is using autoloading of both CSS and JS code.
1204      *
1205      * Major benefit of this compared to standard js/csss loader is much improved
1206      * caching, better browser cache utilisation, much fewer http requests.
1207      *
1208      * @param moodle_page $page
1209      * @return string
1210      */
1211     protected function get_yui3lib_headcode($page) {
1212         global $CFG;
1213
1214         $code = '';
1215
1216         $jsrev = $this->get_jsrev();
1217
1218         $yuiformat = '-min';
1219         if ($this->yui3loader->filter === 'RAW') {
1220             $yuiformat = '';
1221         }
1222
1223         $format = '-min';
1224         if ($this->YUI_config->groups['moodle']['filter'] === 'DEBUG') {
1225             $format = '-debug';
1226         }
1227
1228         $rollupversion = $CFG->yui3version;
1229         if (!empty($CFG->yuipatchlevel)) {
1230             $rollupversion .= '_' . $CFG->yuipatchlevel;
1231         }
1232
1233         $baserollups = array(
1234             'rollup/' . $rollupversion . "/yui-moodlesimple{$yuiformat}.js",
1235             'rollup/' . $jsrev . "/mcore{$format}.js",
1236         );
1237
1238         if ($this->yui3loader->combine) {
1239             if (!empty($page->theme->yuicssmodules)) {
1240                 $modules = array();
1241                 foreach ($page->theme->yuicssmodules as $module) {
1242                     $modules[] = "$CFG->yui3version/$module/$module-min.css";
1243                 }
1244                 $code .= '<link rel="stylesheet" type="text/css" href="'.$this->yui3loader->comboBase.implode('&amp;', $modules).'" />';
1245             }
1246             $code .= '<link rel="stylesheet" type="text/css" href="'.$this->yui3loader->local_comboBase.'rollup/'.$CFG->yui3version.'/yui-moodlesimple' . $yuiformat . '.css" />';
1247             $code .= '<script type="text/javascript" src="'.$this->yui3loader->local_comboBase
1248                     . implode('&amp;', $baserollups) . '"></script>';
1249
1250         } else {
1251             if (!empty($page->theme->yuicssmodules)) {
1252                 foreach ($page->theme->yuicssmodules as $module) {
1253                     $code .= '<link rel="stylesheet" type="text/css" href="'.$this->yui3loader->base.$module.'/'.$module.'-min.css" />';
1254                 }
1255             }
1256             $code .= '<link rel="stylesheet" type="text/css" href="'.$this->yui3loader->local_comboBase.'rollup/'.$CFG->yui3version.'/yui-moodlesimple' . $yuiformat . '.css" />';
1257             foreach ($baserollups as $rollup) {
1258                 $code .= '<script type="text/javascript" src="'.$this->yui3loader->local_comboBase.$rollup.'"></script>';
1259             }
1260         }
1261
1262         if ($this->yui3loader->filter === 'RAW') {
1263             $code = str_replace('-min.css', '.css', $code);
1264         } else if ($this->yui3loader->filter === 'DEBUG') {
1265             $code = str_replace('-min.css', '.css', $code);
1266         }
1267         return $code;
1268     }
1269
1270     /**
1271      * Returns html tags needed for inclusion of theme CSS.
1272      *
1273      * @return string
1274      */
1275     protected function get_css_code() {
1276         // First of all the theme CSS, then any custom CSS
1277         // Please note custom CSS is strongly discouraged,
1278         // because it can not be overridden by themes!
1279         // It is suitable only for things like mod/data which accepts CSS from teachers.
1280         $attributes = array('rel'=>'stylesheet', 'type'=>'text/css');
1281
1282         // This line of code may look funny but it is currently required in order
1283         // to avoid MASSIVE display issues in Internet Explorer.
1284         // As of IE8 + YUI3.1.1 the reference stylesheet (firstthemesheet) gets
1285         // ignored whenever another resource is added until such time as a redraw
1286         // is forced, usually by moving the mouse over the affected element.
1287         $code = html_writer::tag('script', '/** Required in order to fix style inclusion problems in IE with YUI **/', array('id'=>'firstthemesheet', 'type'=>'text/css'));
1288
1289         $urls = $this->cssthemeurls + $this->cssurls;
1290         foreach ($urls as $url) {
1291             $attributes['href'] = $url;
1292             $code .= html_writer::empty_tag('link', $attributes) . "\n";
1293             // This id is needed in first sheet only so that theme may override YUI sheets loaded on the fly.
1294             unset($attributes['id']);
1295         }
1296
1297         return $code;
1298     }
1299
1300     /**
1301      * Adds extra modules specified after printing of page header.
1302      *
1303      * @return string
1304      */
1305     protected function get_extra_modules_code() {
1306         if (empty($this->extramodules)) {
1307             return '';
1308         }
1309         return html_writer::script(js_writer::function_call('M.yui.add_module', array($this->extramodules)));
1310     }
1311
1312     /**
1313      * Generate any HTML that needs to go inside the <head> tag.
1314      *
1315      * Normally, this method is called automatically by the code that prints the
1316      * <head> tag. You should not normally need to call it in your own code.
1317      *
1318      * @param moodle_page $page
1319      * @param core_renderer $renderer
1320      * @return string the HTML code to to inside the <head> tag.
1321      */
1322     public function get_head_code(moodle_page $page, core_renderer $renderer) {
1323         global $CFG;
1324
1325         // Note: the $page and $output are not stored here because it would
1326         // create circular references in memory which prevents garbage collection.
1327         $this->init_requirements_data($page, $renderer);
1328
1329         $output = '';
1330
1331         // Set up the M namespace.
1332         $js = "var M = {}; M.yui = {};\n";
1333
1334         // Capture the time now ASAP during page load. This minimises the lag when
1335         // we try to relate times on the server to times in the browser.
1336         // An example of where this is used is the quiz countdown timer.
1337         $js .= "M.pageloadstarttime = new Date();\n";
1338
1339         // Add a subset of Moodle configuration to the M namespace.
1340         $js .= js_writer::set_variable('M.cfg', $this->M_cfg, false);
1341
1342         // Set up global YUI3 loader object - this should contain all code needed by plugins.
1343         // Note: in JavaScript just use "YUI().use('overlay', function(Y) { .... });",
1344         //       this needs to be done before including any other script.
1345         $js .= $this->YUI_config->get_config_functions();
1346         $js .= js_writer::set_variable('YUI_config', $this->YUI_config, false) . "\n";
1347         $js .= "M.yui.loader = {modules: {}};\n"; // Backwards compatibility only, not used any more.
1348         $js = $this->YUI_config->update_header_js($js);
1349
1350         $output .= html_writer::script($js);
1351
1352         // YUI3 JS and CSS need to be loaded in the header but after the YUI_config has been created.
1353         // They should be cached well by the browser.
1354         $output .= $this->get_yui3lib_headcode($page);
1355
1356         // Add hacked jQuery support, it is not intended for standard Moodle distribution!
1357         $output .= $this->get_jquery_headcode();
1358
1359         // Now theme CSS + custom CSS in this specific order.
1360         $output .= $this->get_css_code();
1361
1362         // Link our main JS file, all core stuff should be there.
1363         $output .= html_writer::script('', $this->js_fix_url('/lib/javascript-static.js'));
1364
1365         // Add variables.
1366         if ($this->jsinitvariables['head']) {
1367             $js = '';
1368             foreach ($this->jsinitvariables['head'] as $data) {
1369                 list($var, $value) = $data;
1370                 $js .= js_writer::set_variable($var, $value, true);
1371             }
1372             $output .= html_writer::script($js);
1373         }
1374
1375         // All the other linked things from HEAD - there should be as few as possible.
1376         if ($this->jsincludes['head']) {
1377             foreach ($this->jsincludes['head'] as $url) {
1378                 $output .= html_writer::script('', $url);
1379             }
1380         }
1381
1382         // Mark head sending done, it is not possible to anything there.
1383         $this->headdone = true;
1384
1385         return $output;
1386     }
1387
1388     /**
1389      * Generate any HTML that needs to go at the start of the <body> tag.
1390      *
1391      * Normally, this method is called automatically by the code that prints the
1392      * <head> tag. You should not normally need to call it in your own code.
1393      *
1394      * @return string the HTML code to go at the start of the <body> tag.
1395      */
1396     public function get_top_of_body_code() {
1397         // First the skip links.
1398         $links = '';
1399         $attributes = array('class'=>'skip');
1400         foreach ($this->skiplinks as $url => $text) {
1401             $attributes['href'] = '#' . $url;
1402             $links .= html_writer::tag('a', $text, $attributes);
1403         }
1404         $output = html_writer::tag('div', $links, array('class'=>'skiplinks')) . "\n";
1405
1406         // Then the clever trick for hiding of things not needed when JS works.
1407         $output .= html_writer::script("document.body.className += ' jsenabled';") . "\n";
1408         $this->topofbodydone = true;
1409         return $output;
1410     }
1411
1412     /**
1413      * Generate any HTML that needs to go at the end of the page.
1414      *
1415      * Normally, this method is called automatically by the code that prints the
1416      * page footer. You should not normally need to call it in your own code.
1417      *
1418      * @return string the HTML code to to at the end of the page.
1419      */
1420     public function get_end_code() {
1421         global $CFG;
1422
1423         // Add other requested modules.
1424         $output = $this->get_extra_modules_code();
1425
1426         $this->js_init_code('M.util.js_complete("init");', true);
1427
1428         // All the other linked scripts - there should be as few as possible.
1429         if ($this->jsincludes['footer']) {
1430             foreach ($this->jsincludes['footer'] as $url) {
1431                 $output .= html_writer::script('', $url);
1432             }
1433         }
1434
1435         // Add all needed strings.
1436         // First add core strings required for some dialogues.
1437         $this->strings_for_js(array(
1438             'confirm',
1439             'yes',
1440             'no',
1441             'areyousure',
1442             'closebuttontitle',
1443             'unknownerror',
1444         ), 'moodle');
1445         if (!empty($this->stringsforjs)) {
1446             $strings = array();
1447             foreach ($this->stringsforjs as $component=>$v) {
1448                 foreach($v as $indentifier => $langstring) {
1449                     $strings[$component][$indentifier] = $langstring->out();
1450                 }
1451             }
1452             $output .= html_writer::script(js_writer::set_variable('M.str', $strings));
1453         }
1454
1455         // Add variables.
1456         if ($this->jsinitvariables['footer']) {
1457             $js = '';
1458             foreach ($this->jsinitvariables['footer'] as $data) {
1459                 list($var, $value) = $data;
1460                 $js .= js_writer::set_variable($var, $value, true);
1461             }
1462             $output .= html_writer::script($js);
1463         }
1464
1465         $inyuijs = $this->get_javascript_code(false);
1466         $ondomreadyjs = $this->get_javascript_code(true);
1467         $jsinit = $this->get_javascript_init_code();
1468         $handlersjs = $this->get_event_handler_code();
1469
1470         // There is no global Y, make sure it is available in your scope.
1471         $js = "YUI().use('node', function(Y) {\n{$inyuijs}{$ondomreadyjs}{$jsinit}{$handlersjs}\n});";
1472
1473         $output .= html_writer::script($js);
1474
1475         return $output;
1476     }
1477
1478     /**
1479      * Have we already output the code in the <head> tag?
1480      *
1481      * @return bool
1482      */
1483     public function is_head_done() {
1484         return $this->headdone;
1485     }
1486
1487     /**
1488      * Have we already output the code at the start of the <body> tag?
1489      *
1490      * @return bool
1491      */
1492     public function is_top_of_body_done() {
1493         return $this->topofbodydone;
1494     }
1495 }
1496
1497 /**
1498  * This class represents the YUI configuration.
1499  *
1500  * @copyright 2013 Andrew Nicols
1501  * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
1502  * @since Moodle 2.5
1503  * @package core
1504  * @category output
1505  */
1506 class YUI_config {
1507     /**
1508      * These settings must be public so that when the object is converted to json they are exposed.
1509      * Note: Some of these are camelCase because YUI uses camelCase variable names.
1510      *
1511      * The settings are described and documented in the YUI API at:
1512      * - http://yuilibrary.com/yui/docs/api/classes/config.html
1513      * - http://yuilibrary.com/yui/docs/api/classes/Loader.html
1514      */
1515     public $debug = false;
1516     public $base;
1517     public $comboBase;
1518     public $combine;
1519     public $filter = null;
1520     public $insertBefore = 'firstthemesheet';
1521     public $groups = array();
1522     public $modules = array();
1523
1524     /**
1525      * @var array List of functions used by the YUI Loader group pattern recognition.
1526      */
1527     protected $jsconfigfunctions = array();
1528
1529     /**
1530      * Create a new group within the YUI_config system.
1531      *
1532      * @param String $name The name of the group. This must be unique and
1533      * not previously used.
1534      * @param Array $config The configuration for this group.
1535      * @return void
1536      */
1537     public function add_group($name, $config) {
1538         if (isset($this->groups[$name])) {
1539             throw new coding_exception("A YUI configuration group for '{$name}' already exists. To make changes to this group use YUI_config->update_group().");
1540         }
1541         $this->groups[$name] = $config;
1542     }
1543
1544     /**
1545      * Update an existing group configuration
1546      *
1547      * Note, any existing configuration for that group will be wiped out.
1548      * This includes module configuration.
1549      *
1550      * @param String $name The name of the group. This must be unique and
1551      * not previously used.
1552      * @param Array $config The configuration for this group.
1553      * @return void
1554      */
1555     public function update_group($name, $config) {
1556         if (!isset($this->groups[$name])) {
1557             throw new coding_exception('The Moodle YUI module does not exist. You must define the moodle module config using YUI_config->add_module_config first.');
1558         }
1559         $this->groups[$name] = $config;
1560     }
1561
1562     /**
1563      * Set the value of a configuration function used by the YUI Loader's pattern testing.
1564      *
1565      * Only the body of the function should be passed, and not the whole function wrapper.
1566      *
1567      * The JS function your write will be passed a single argument 'name' containing the
1568      * name of the module being loaded.
1569      *
1570      * @param $function String the body of the JavaScript function. This should be used i
1571      * @return String the name of the function to use in the group pattern configuration.
1572      */
1573     public function set_config_function($function) {
1574         $configname = 'yui' . (count($this->jsconfigfunctions) + 1) . 'ConfigFn';
1575         if (isset($this->jsconfigfunctions[$configname])) {
1576             throw new coding_exception("A YUI config function with this name already exists. Config function names must be unique.");
1577         }
1578         $this->jsconfigfunctions[$configname] = $function;
1579         return '@' . $configname . '@';
1580     }
1581
1582     /**
1583      * Allow setting of the config function described in {@see set_config_function} from a file.
1584      * The contents of this file are then passed to set_config_function.
1585      *
1586      * When jsrev is positive, the function is minified and stored in a MUC cache for subsequent uses.
1587      *
1588      * @param $file The path to the JavaScript function used for YUI configuration.
1589      * @return String the name of the function to use in the group pattern configuration.
1590      */
1591     public function set_config_source($file) {
1592         global $CFG;
1593         $cache = cache::make('core', 'yuimodules');
1594
1595         // Attempt to get the metadata from the cache.
1596         $keyname = 'configfn_' . $file;
1597         $fullpath = $CFG->dirroot . '/' . $file;
1598         if (!isset($CFG->jsrev) || $CFG->jsrev == -1) {
1599             $cache->delete($keyname);
1600             $configfn = file_get_contents($fullpath);
1601         } else {
1602             $configfn = $cache->get($keyname);
1603             if ($configfn === false) {
1604                 require_once($CFG->libdir . '/jslib.php');
1605                 $configfn = core_minify::js_files(array($fullpath));
1606                 $cache->set($keyname, $configfn);
1607             }
1608         }
1609         return $this->set_config_function($configfn);
1610     }
1611
1612     /**
1613      * Retrieve the list of JavaScript functions for YUI_config groups.
1614      *
1615      * @return String The complete set of config functions
1616      */
1617     public function get_config_functions() {
1618         $configfunctions = '';
1619         foreach ($this->jsconfigfunctions as $functionname => $function) {
1620             $configfunctions .= "var {$functionname} = function(me) {";
1621             $configfunctions .= $function;
1622             $configfunctions .= "};\n";
1623         }
1624         return $configfunctions;
1625     }
1626
1627     /**
1628      * Update the header JavaScript with any required modification for the YUI Loader.
1629      *
1630      * @param $js String The JavaScript to manipulate.
1631      * @return String the modified JS string.
1632      */
1633     public function update_header_js($js) {
1634         // Update the names of the the configFn variables.
1635         // The PHP json_encode function cannot handle literal names so we have to wrap
1636         // them in @ and then replace them with literals of the same function name.
1637         foreach ($this->jsconfigfunctions as $functionname => $function) {
1638             $js = str_replace('"@' . $functionname . '@"', $functionname, $js);
1639         }
1640         return $js;
1641     }
1642
1643     /**
1644      * Add configuration for a specific module.
1645      *
1646      * @param String $name The name of the module to add configuration for.
1647      * @param Array $config The configuration for the specified module.
1648      * @param String $group The name of the group to add configuration for.
1649      * If not specified, then this module is added to the global
1650      * configuration.
1651      * @return void
1652      */
1653     public function add_module_config($name, $config, $group = null) {
1654         if ($group) {
1655             if (!isset($this->groups[$name])) {
1656                 throw new coding_exception('The Moodle YUI module does not exist. You must define the moodle module config using YUI_config->add_module_config first.');
1657             }
1658             if (!isset($this->groups[$group]['modules'])) {
1659                 $this->groups[$group]['modules'] = array();
1660             }
1661             $modules = &$this->groups[$group]['modules'];
1662         } else {
1663             $modules = &$this->modules;
1664         }
1665         $modules[$name] = $config;
1666     }
1667
1668     /**
1669      * Add the moodle YUI module metadata for the moodle group to the YUI_config instance.
1670      *
1671      * If js caching is disabled, metadata will not be served causing YUI to calculate
1672      * module dependencies as each module is loaded.
1673      *
1674      * If metadata does not exist it will be created and stored in a MUC entry.
1675      *
1676      * @return void
1677      */
1678     public function add_moodle_metadata() {
1679         global $CFG;
1680         if (!isset($this->groups['moodle'])) {
1681             throw new coding_exception('The Moodle YUI module does not exist. You must define the moodle module config using YUI_config->add_module_config first.');
1682         }
1683
1684         if (!isset($this->groups['moodle']['modules'])) {
1685             $this->groups['moodle']['modules'] = array();
1686         }
1687
1688         $cache = cache::make('core', 'yuimodules');
1689         if (!isset($CFG->jsrev) || $CFG->jsrev == -1) {
1690             $metadata = array();
1691             $metadata = $this->get_moodle_metadata();
1692             $cache->delete('metadata');
1693         } else {
1694             // Attempt to get the metadata from the cache.
1695             if (!$metadata = $cache->get('metadata')) {
1696                 $metadata = $this->get_moodle_metadata();
1697                 $cache->set('metadata', $metadata);
1698             }
1699         }
1700
1701         // Merge with any metadata added specific to this page which was added manually.
1702         $this->groups['moodle']['modules'] = array_merge($this->groups['moodle']['modules'],
1703                 $metadata);
1704     }
1705
1706     /**
1707      * Determine the module metadata for all moodle YUI modules.
1708      *
1709      * This works through all modules capable of serving YUI modules, and attempts to get
1710      * metadata for each of those modules.
1711      *
1712      * @return Array of module metadata
1713      */
1714     private function get_moodle_metadata() {
1715         $moodlemodules = array();
1716         // Core isn't a plugin type or subsystem - handle it seperately.
1717         if ($module = $this->get_moodle_path_metadata(core_component::get_component_directory('core'))) {
1718             $moodlemodules = array_merge($moodlemodules, $module);
1719         }
1720
1721         // Handle other core subsystems.
1722         $subsystems = core_component::get_core_subsystems();
1723         foreach ($subsystems as $subsystem => $path) {
1724             if (is_null($path)) {
1725                 continue;
1726             }
1727             if ($module = $this->get_moodle_path_metadata($path)) {
1728                 $moodlemodules = array_merge($moodlemodules, $module);
1729             }
1730         }
1731
1732         // And finally the plugins.
1733         $plugintypes = core_component::get_plugin_types();
1734         foreach ($plugintypes as $plugintype => $pathroot) {
1735             $pluginlist = core_component::get_plugin_list($plugintype);
1736             foreach ($pluginlist as $plugin => $path) {
1737                 if ($module = $this->get_moodle_path_metadata($path)) {
1738                     $moodlemodules = array_merge($moodlemodules, $module);
1739                 }
1740             }
1741         }
1742
1743         return $moodlemodules;
1744     }
1745
1746     /**
1747      * Helper function process and return the YUI metadata for all of the modules under the specified path.
1748      *
1749      * @param String $path the UNC path to the YUI src directory.
1750      * @return Array the complete array for frankenstyle directory.
1751      */
1752     private function get_moodle_path_metadata($path) {
1753         // Add module metadata is stored in frankenstyle_modname/yui/src/yui_modname/meta/yui_modname.json.
1754         $baseyui = $path . '/yui/src';
1755         $modules = array();
1756         if (is_dir($baseyui)) {
1757             $items = new DirectoryIterator($baseyui);
1758             foreach ($items as $item) {
1759                 if ($item->isDot() or !$item->isDir()) {
1760                     continue;
1761                 }
1762                 $metafile = realpath($baseyui . '/' . $item . '/meta/' . $item . '.json');
1763                 if (!is_readable($metafile)) {
1764                     continue;
1765                 }
1766                 $metadata = file_get_contents($metafile);
1767                 $modules = array_merge($modules, (array) json_decode($metadata));
1768             }
1769         }
1770         return $modules;
1771     }
1772
1773     /**
1774      * Define YUI modules which we have been required to patch between releases.
1775      *
1776      * We must do this because we aggressively cache content on the browser, and we must also override use of the
1777      * external CDN which will serve the true authoritative copy of the code without our patches.
1778      *
1779      * @param String combobase The local combobase
1780      * @param String yuiversion The current YUI version
1781      * @param Int patchlevel The patch level we're working to for YUI
1782      * @param Array patchedmodules An array containing the names of the patched modules
1783      * @return void
1784      */
1785     public function define_patched_core_modules($combobase, $yuiversion, $patchlevel, $patchedmodules) {
1786         // The version we use is suffixed with a patchlevel so that we can get additional revisions between YUI releases.
1787         $subversion = $yuiversion . '_' . $patchlevel;
1788
1789         if ($this->comboBase == $combobase) {
1790             // If we are using the local combobase in the loader, we can add a group and still make use of the combo
1791             // loader. We just need to specify a different root which includes a slightly different YUI version number
1792             // to include our patchlevel.
1793             $patterns = array();
1794             $modules = array();
1795             foreach ($patchedmodules as $modulename) {
1796                 // We must define the pattern and module here so that the loader uses our group configuration instead of
1797                 // the standard module definition. We may lose some metadata provided by upstream but this will be
1798                 // loaded when the module is loaded anyway.
1799                 $patterns[$modulename] = array(
1800                     'group' => 'yui-patched',
1801                 );
1802                 $modules[$modulename] = array();
1803             }
1804
1805             // Actually add the patch group here.
1806             $this->add_group('yui-patched', array(
1807                 'combine' => true,
1808                 'root' => $subversion . '/',
1809                 'patterns' => $patterns,
1810                 'modules' => $modules,
1811             ));
1812
1813         } else {
1814             // The CDN is in use - we need to instead use the local combobase for this module and override the modules
1815             // definition. We cannot use the local base - we must use the combobase because we cannot invalidate the
1816             // local base in browser caches.
1817             $fullpathbase = $combobase . $subversion . '/';
1818             foreach ($patchedmodules as $modulename) {
1819                 $this->modules[$modulename] = array(
1820                     'fullpath' => $fullpathbase . $modulename . '/' . $modulename . '-min.js'
1821                 );
1822             }
1823         }
1824     }
1825 }
1826
1827 /**
1828  * Invalidate all server and client side JS caches.
1829  */
1830 function js_reset_all_caches() {
1831     global $CFG;
1832
1833     $next = time();
1834     if (isset($CFG->jsrev) and $next <= $CFG->jsrev and $CFG->jsrev - $next < 60*60) {
1835         // This resolves problems when reset is requested repeatedly within 1s,
1836         // the < 1h condition prevents accidental switching to future dates
1837         // because we might not recover from it.
1838         $next = $CFG->jsrev+1;
1839     }
1840
1841     set_config('jsrev', $next);
1842 }