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 Stores debug backtraces from when JS modules were included in the page
 145      */
 146     protected $debug_moduleloadstacktraces = array();
 147
 148     /**
 149      * @var array list of requested jQuery plugins
 150      */
 151     protected $jqueryplugins = array();
 152
 153     /**
 154      * @var array list of jQuery plugin overrides
 155      */
 156     protected $jquerypluginoverrides = array();
 157
 158     /**
 159      * Page requirements constructor.
 160      */
 161     public function __construct() {
 162         global $CFG;
 163
 164         // You may need to set up URL rewrite rule because oversized URLs might not be allowed by web server.
 165         $sep = empty($CFG->yuislasharguments) ? '?' : '/';
 166
 167         $this->yui3loader = new stdClass();
 168         $this->YUI_config = new YUI_config();
 169
 170         // Set up some loader options.
 171         if (!empty($CFG->useexternalyui) and strpos($CFG->httpswwwroot, 'https:') !== 0) {
 172             $this->yui3loader->base = 'http://yui.yahooapis.com/' . $CFG->yui3version . '/build/';
 173             $this->yui3loader->comboBase = 'http://yui.yahooapis.com/combo?';
 174         } else {
 175             $this->yui3loader->base = $CFG->httpswwwroot . '/lib/yuilib/'. $CFG->yui3version . '/build/';
 176             $this->yui3loader->comboBase = $CFG->httpswwwroot . '/theme/yui_combo.php'.$sep;
 177         }
 178
 179         // Enable combo loader? This significantly helps with caching and performance!
 180         $this->yui3loader->combine = !empty($CFG->yuicomboloading);
 181
 182         if (empty($CFG->cachejs)) {
 183             $jsrev = -1;
 184         } else if (empty($CFG->jsrev)) {
 185             $jsrev = 1;
 186         } else {
 187             $jsrev = $CFG->jsrev;
 188         }
 189
 190         // Set up JS YUI loader helper object.
 191         $this->YUI_config->base         = $this->yui3loader->base;
 192         $this->YUI_config->comboBase    = $this->yui3loader->comboBase;
 193         $this->YUI_config->combine      = $this->yui3loader->combine;
 194
 195         $configname = $this->YUI_config->set_config_function("if(/-skin|reset|fonts|grids|base/.test(me.name)){me.type='css';me.path=me.path.replace(/\.js/,'.css');me.path=me.path.replace(/\/yui2-skin/,'/assets/skins/sam/yui2-skin');}");
 196         $this->YUI_config->add_group('yui2', array(
 197             // Loader configuration for our 2in3, for now ignores $CFG->useexternalyui.
 198             'base' => $CFG->httpswwwroot . '/lib/yuilib/2in3/' . $CFG->yui2version . '/build/',
 199             'comboBase' => $CFG->httpswwwroot . '/theme/yui_combo.php'.$sep,
 200             'combine' => $this->yui3loader->combine,
 201             'ext' => false,
 202             'root' => '2in3/' . $CFG->yui2version .'/build/',
 203             'patterns' => array(
 204                 'yui2-' => array(
 205                     'group' => 'yui2',
 206                     'configFn' => $configname,
 207                 )
 208             )
 209         ));
 210         $configname = $this->YUI_config->set_config_function("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;if(me.type !== 'css'){me.path=me.path+'-min';};me.path=me.path+'.'+me.type;");
 211         $this->YUI_config->add_group('moodle', array(
 212             'name' => 'moodle',
 213             'base' => $CFG->httpswwwroot . '/theme/yui_combo.php'.$sep.'moodle/'.$jsrev.'/',
 214             'combine' => $this->yui3loader->combine,
 215             'comboBase' => $CFG->httpswwwroot . '/theme/yui_combo.php'.$sep,
 216             'ext' => false,
 217             'root' => 'moodle/'.$jsrev.'/', // Add the rev to the root path so that we can control caching.
 218             'patterns' => array(
 219                 'moodle-' => array(
 220                     'group' => 'moodle',
 221                     'configFn' => $configname,
 222                 )
 223             )
 224         ));
 225
 226         // Set some more loader options applying to groups too.
 227         if (debugging('', DEBUG_DEVELOPER)) {
 228             // When debugging is enabled, we want to load the non-minified (RAW) versions of YUI library modules rather
 229             // than the DEBUG versions as these generally generate too much logging for our purposes.
 230             // However we do want the DEBUG versions of our Moodle-specific modules.
 231             // To debug a YUI-specific issue, change the yui3loader->filter value to DEBUG.
 232             $this->YUI_config->filter = 'RAW';
 233             $this->YUI_config->groups['moodle']['filter'] = 'DEBUG';
 234
 235             // We use the yui3loader->filter setting when writing the YUI3 seed scripts into the header.
 236             $this->yui3loader->filter = $this->YUI_config->filter;
 237             $this->YUI_config->debug = true;
 238         } else {
 239             $this->yui3loader->filter = null;
 240             $this->YUI_config->debug = false;
 241         }
 242
 243         // Add the moodle group's module data.
 244         $this->YUI_config->add_moodle_metadata();
 245
 246         // Every page should include definition of following modules.
 247         $this->js_module($this->find_module('core_filepicker'));
 248         $this->js_module($this->find_module('core_dock'));
 249     }
 250
 251     /**
 252      * Initialise with the bits of JavaScript that every Moodle page should have.
 253      *
 254      * @param moodle_page $page
 255      * @param core_renderer $renderer
 256      */
 257     protected function init_requirements_data(moodle_page $page, core_renderer $renderer) {
 258         global $CFG;
 259
 260         // JavaScript should always work with $CFG->httpswwwroot rather than $CFG->wwwroot.
 261         // Otherwise, in some situations, users will get warnings about insecure content
 262         // on secure pages from their web browser.
 263
 264         $this->M_cfg = array(
 265             'wwwroot'             => $CFG->httpswwwroot, // Yes, really. See above.
 266             'sesskey'             => sesskey(),
 267             'loadingicon'         => $renderer->pix_url('i/loading_small', 'moodle')->out(false),
 268             'themerev'            => theme_get_revision(),
 269             'slasharguments'      => (int)(!empty($CFG->slasharguments)),
 270             'theme'               => $page->theme->name,
 271             'jsrev'               => ((empty($CFG->cachejs) or empty($CFG->jsrev)) ? -1 : $CFG->jsrev),
 272             'svgicons'            => $page->theme->use_svg_icons()
 273         );
 274         if (debugging('', DEBUG_DEVELOPER)) {
 275             $this->M_cfg['developerdebug'] = true;
 276         }
 277         if (defined('BEHAT_SITE_RUNNING')) {
 278             $this->M_cfg['behatsiterunning'] = true;
 279         }
 280
 281         // Accessibility stuff.
 282         $this->skip_link_to('maincontent', get_string('tocontent', 'access'));
 283
 284         // Add strings used on many pages.
 285         $this->string_for_js('confirmation', 'admin');
 286         $this->string_for_js('cancel', 'moodle');
 287         $this->string_for_js('yes', 'moodle');
 288
 289         // Alter links in top frame to break out of frames.
 290         if ($page->pagelayout === 'frametop') {
 291             $this->js_init_call('M.util.init_frametop');
 292         }
 293
 294         // Include block drag/drop if editing is on
 295         if ($page->user_is_editing()) {
 296             $params = array(
 297                 'courseid' => $page->course->id,
 298                 'pagetype' => $page->pagetype,
 299                 'pagelayout' => $page->pagelayout,
 300                 'subpage' => $page->subpage,
 301                 'regions' => $page->blocks->get_regions(),
 302                 'contextid' => $page->context->id,
 303             );
 304             if (!empty($page->cm->id)) {
 305                 $params['cmid'] = $page->cm->id;
 306             }
 307             $page->requires->yui_module('moodle-core-blocks', 'M.core_blocks.init_dragdrop', array($params), null, true);
 308         }
 309     }
 310
 311     /**
 312      * Ensure that the specified JavaScript file is linked to from this page.
 313      *
 314      * NOTE: This function is to be used in RARE CASES ONLY, please store your JS in module.js file
 315      * and use $PAGE->requires->js_init_call() instead or use /yui/ subdirectories for YUI modules.
 316      *
 317      * By default the link is put at the end of the page, since this gives best page-load performance.
 318      *
 319      * Even if a particular script is requested more than once, it will only be linked
 320      * to once.
 321      *
 322      * @param string|moodle_url $url The path to the .js file, relative to $CFG->dirroot / $CFG->wwwroot.
 323      *      For example '/mod/mymod/customscripts.js'; use moodle_url for external scripts
 324      * @param bool $inhead initialise in head
 325      */
 326     public function js($url, $inhead = false) {
 327         $url = $this->js_fix_url($url);
 328         $where = $inhead ? 'head' : 'footer';
 329         $this->jsincludes[$where][$url->out()] = $url;
 330     }
 331
 332     /**
 333      * Request inclusion of jQuery library in the page.
 334      *
 335      * NOTE: this should not be used in official Moodle distribution!
 336      *
 337      * We are going to bundle jQuery 1.9.x until we drop support
 338      * all support for IE 6-8. Use $PAGE->requires->jquery_plugin('migrate')
 339      * for code written for earlier jQuery versions.
 340      *
 341      * {@see http://docs.moodle.org/dev/jQuery}
 342      */
 343     public function jquery() {
 344         $this->jquery_plugin('jquery');
 345     }
 346
 347     /**
 348      * Request inclusion of jQuery plugin.
 349      *
 350      * NOTE: this should not be used in official Moodle distribution!
 351      *
 352      * jQuery plugins are located in plugin/jquery/* subdirectory,
 353      * plugin/jquery/plugins.php lists all available plugins.
 354      *
 355      * Included core plugins:
 356      *   - jQuery UI
 357      *   - jQuery Migrate (useful for code written for previous UI version)
 358      *
 359      * Add-ons may include extra jQuery plugins in jquery/ directory,
 360      * plugins.php file defines the mapping between plugin names and
 361      * necessary page includes.
 362      *
 363      * Examples:
 364      * <code>
 365      *   // file: mod/xxx/view.php
 366      *   $PAGE->requires->jquery();
 367      *   $PAGE->requires->jquery_plugin('ui');
 368      *   $PAGE->requires->jquery_plugin('ui-css');
 369      * </code>
 370      *
 371      * <code>
 372      *   // file: theme/yyy/lib.php
 373      *   function theme_yyy_page_init(moodle_page $page) {
 374      *       $page->requires->jquery();
 375      *       $page->requires->jquery_plugin('ui');
 376      *       $page->requires->jquery_plugin('ui-css');
 377      *   }
 378      * </code>
 379      *
 380      * <code>
 381      *   // file: blocks/zzz/block_zzz.php
 382      *   public function get_required_javascript() {
 383      *       parent::get_required_javascript();
 384      *       $this->page->requires->jquery();
 385      *       $page->requires->jquery_plugin('ui');
 386      *       $page->requires->jquery_plugin('ui-css');
 387      *   }
 388      * </code>
 389      *
 390      * {@see http://docs.moodle.org/dev/jQuery}
 391      *
 392      * @param string $plugin name of the jQuery plugin as defined in jquery/plugins.php
 393      * @param string $component name of the component
 394      * @return bool success
 395      */
 396     public function jquery_plugin($plugin, $component = 'core') {
 397         global $CFG;
 398
 399         if ($this->headdone) {
 400             debugging('Can not add jQuery plugins after starting page output!');
 401             return false;
 402         }
 403
 404         if ($component !== 'core' and in_array($plugin, array('jquery', 'ui', 'ui-css', 'migrate'))) {
 405             debugging("jQuery plugin '$plugin' is included in Moodle core, other components can not use the same name.", DEBUG_DEVELOPER);
 406             $component = 'core';
 407         } else if ($component !== 'core' and strpos($component, '_') === false) {
 408             // Let's normalise the legacy activity names, Frankenstyle rulez!
 409             $component = 'mod_' . $component;
 410         }
 411
 412         if (empty($this->jqueryplugins) and ($component !== 'core' or $plugin !== 'jquery')) {
 413             // Make sure the jQuery itself is always loaded first,
 414             // the order of all other plugins depends on order of $PAGE_>requires->.
 415             $this->jquery_plugin('jquery', 'core');
 416         }
 417
 418         if (isset($this->jqueryplugins[$plugin])) {
 419             // No problem, we already have something, first Moodle plugin to register the jQuery plugin wins.
 420             return true;
 421         }
 422
 423         $componentdir = get_component_directory($component);
 424         if (!file_exists($componentdir) or !file_exists("$componentdir/jquery/plugins.php")) {
 425             debugging("Can not load jQuery plugin '$plugin', missing plugins.php in component '$component'.", DEBUG_DEVELOPER);
 426             return false;
 427         }
 428
 429         $plugins = array();
 430         require("$componentdir/jquery/plugins.php");
 431
 432         if (!isset($plugins[$plugin])) {
 433             debugging("jQuery plugin '$plugin' can not be found in component '$component'.", DEBUG_DEVELOPER);
 434             return false;
 435         }
 436
 437         $this->jqueryplugins[$plugin] = new stdClass();
 438         $this->jqueryplugins[$plugin]->plugin    = $plugin;
 439         $this->jqueryplugins[$plugin]->component = $component;
 440         $this->jqueryplugins[$plugin]->urls      = array();
 441
 442         foreach ($plugins[$plugin]['files'] as $file) {
 443             if (debugging('', DEBUG_DEVELOPER)) {
 444                 if (!file_exists("$componentdir/jquery/$file")) {
 445                     debugging("Invalid file '$file' specified in jQuery plugin '$plugin' in component '$component'");
 446                     continue;
 447                 }
 448                 $file = str_replace('.min.css', '.css', $file);
 449                 $file = str_replace('.min.js', '.js', $file);
 450             }
 451             if (!file_exists("$componentdir/jquery/$file")) {
 452                 debugging("Invalid file '$file' specified in jQuery plugin '$plugin' in component '$component'");
 453                 continue;
 454             }
 455             if (!empty($CFG->slasharguments)) {
 456                 $url = new moodle_url("$CFG->httpswwwroot/theme/jquery.php");
 457                 $url->set_slashargument("/$component/$file");
 458
 459             } else {
 460                 // This is not really good, we need slasharguments for relative links, this means no caching...
 461                 $path = realpath("$componentdir/jquery/$file");
 462                 if (strpos($path, $CFG->dirroot) === 0) {
 463                     $url = $CFG->httpswwwroot.preg_replace('/^'.preg_quote($CFG->dirroot, '/').'/', '', $path);
 464                     $url = new moodle_url($url);
 465                 } else {
 466                     // Bad luck, fix your server!
 467                     debugging("Moodle jQuery integration requires 'slasharguments' setting to be enabled.");
 468                     continue;
 469                 }
 470             }
 471             $this->jqueryplugins[$plugin]->urls[] = $url;
 472         }
 473
 474         return true;
 475     }
 476
 477     /**
 478      * Request replacement of one jQuery plugin by another.
 479      *
 480      * This is useful when themes want to replace the jQuery UI theme,
 481      * the problem is that theme can not prevent others from including the core ui-css plugin.
 482      *
 483      * Example:
 484      *  1/ generate new jQuery UI theme and place it into theme/yourtheme/jquery/
 485      *  2/ write theme/yourtheme/jquery/plugins.php
 486      *  3/ init jQuery from theme
 487      *
 488      * <code>
 489      *   // file theme/yourtheme/lib.php
 490      *   function theme_yourtheme_page_init($page) {
 491      *       $page->requires->jquery_plugin('yourtheme-ui-css', 'theme_yourtheme');
 492      *       $page->requires->jquery_override_plugin('ui-css', 'yourtheme-ui-css');
 493      *   }
 494      * </code>
 495      *
 496      * This code prevents loading of standard 'ui-css' which my be requested by other plugins,
 497      * the 'yourtheme-ui-css' gets loaded only if some other code requires jquery.
 498      *
 499      * {@see http://docs.moodle.org/dev/jQuery}
 500      *
 501      * @param string $oldplugin original plugin
 502      * @param string $newplugin the replacement
 503      */
 504     public function jquery_override_plugin($oldplugin, $newplugin) {
 505         if ($this->headdone) {
 506             debugging('Can not override jQuery plugins after starting page output!');
 507             return;
 508         }
 509         $this->jquerypluginoverrides[$oldplugin] = $newplugin;
 510     }
 511
 512     /**
 513      * Return jQuery related markup for page start.
 514      * @return string
 515      */
 516     protected function get_jquery_headcode() {
 517         if (empty($this->jqueryplugins['jquery'])) {
 518             // If nobody requested jQuery then do not bother to load anything.
 519             // This may be useful for themes that want to override 'ui-css' only if requested by something else.
 520             return '';
 521         }
 522
 523         $included = array();
 524         $urls = array();
 525
 526         foreach ($this->jqueryplugins as $name => $unused) {
 527             if (isset($included[$name])) {
 528                 continue;
 529             }
 530             if (array_key_exists($name, $this->jquerypluginoverrides)) {
 531                 // The following loop tries to resolve the replacements,
 532                 // use max 100 iterations to prevent infinite loop resulting
 533                 // in blank page.
 534                 $cyclic = true;
 535                 $oldname = $name;
 536                 for ($i=0; $i<100; $i++) {
 537                     $name = $this->jquerypluginoverrides[$name];
 538                     if (!array_key_exists($name, $this->jquerypluginoverrides)) {
 539                         $cyclic = false;
 540                         break;
 541                     }
 542                 }
 543                 if ($cyclic) {
 544                     // We can not do much with cyclic references here, let's use the old plugin.
 545                     $name = $oldname;
 546                     debugging("Cyclic overrides detected for jQuery plugin '$name'");
 547
 548                 } else if (empty($name)) {
 549                     // Developer requested removal of the plugin.
 550                     continue;
 551
 552                 } else if (!isset($this->jqueryplugins[$name])) {
 553                     debugging("Unknown jQuery override plugin '$name' detected");
 554                     $name = $oldname;
 555
 556                 } else if (isset($included[$name])) {
 557                     // The plugin was already included, easy.
 558                     continue;
 559                 }
 560             }
 561
 562             $plugin = $this->jqueryplugins[$name];
 563             $urls = array_merge($urls, $plugin->urls);
 564             $included[$name] = true;
 565         }
 566
 567         $output = '';
 568         $attributes = array('rel' => 'stylesheet', 'type' => 'text/css');
 569         foreach ($urls as $url) {
 570             if (preg_match('/\.js$/', $url)) {
 571                 $output .= html_writer::script('', $url);
 572             } else if (preg_match('/\.css$/', $url)) {
 573                 $attributes['href'] = $url;
 574                 $output .= html_writer::empty_tag('link', $attributes) . "\n";
 575             }
 576         }
 577
 578         return $output;
 579     }
 580
 581     /**
 582      * This method was used to load YUI2 libraries into global scope,
 583      * use YUI 2in3 instead. Every YUI2 module is represented as a yui2-*
 584      * sandboxed module in YUI3 code via Y.YUI2. property.
 585      *
 586      * {@see http://tracker.moodle.org/browse/MDL-34741}
 587      *
 588      * @param string|array $libname
 589      * @deprecated since 2.4
 590      */
 591     public function yui2_lib($libname) {
 592         throw new coding_exception('PAGE->yui2_lib() is not available any more, use YUI 2in3 instead, see MDL-34741 for more information.');
 593     }
 594
 595     /**
 596      * Returns the actual url through which a script is served.
 597      *
 598      * @param moodle_url|string $url full moodle url, or shortened path to script
 599      * @return moodle_url
 600      */
 601     protected function js_fix_url($url) {
 602         global $CFG;
 603
 604         if ($url instanceof moodle_url) {
 605             return $url;
 606         } else if (strpos($url, '/') === 0) {
 607             // Fix the admin links if needed.
 608             if ($CFG->admin !== 'admin') {
 609                 if (strpos($url, "/admin/") === 0) {
 610                     $url = preg_replace("|^/admin/|", "/$CFG->admin/", $url);
 611                 }
 612             }
 613             if (debugging()) {
 614                 // Check file existence only when in debug mode.
 615                 if (!file_exists($CFG->dirroot . strtok($url, '?'))) {
 616                     throw new coding_exception('Attempt to require a JavaScript file that does not exist.', $url);
 617                 }
 618             }
 619             if (!empty($CFG->cachejs) and !empty($CFG->jsrev) and $CFG->jsrev > 0 and substr($url, -3) === '.js') {
 620                 if (empty($CFG->slasharguments)) {
 621                     return new moodle_url($CFG->httpswwwroot.'/lib/javascript.php', array('rev'=>$CFG->jsrev, 'jsfile'=>$url));
 622                 } else {
 623                     $returnurl = new moodle_url($CFG->httpswwwroot.'/lib/javascript.php');
 624                     $returnurl->set_slashargument('/'.$CFG->jsrev.$url);
 625                     return $returnurl;
 626                 }
 627             } else {
 628                 return new moodle_url($CFG->httpswwwroot.$url);
 629             }
 630         } else {
 631             throw new coding_exception('Invalid JS url, it has to be shortened url starting with / or moodle_url instance.', $url);
 632         }
 633     }
 634
 635     /**
 636      * Find out if JS module present and return details.
 637      *
 638      * @param string $component name of component in frankenstyle, ex: core_group, mod_forum
 639      * @return array description of module or null if not found
 640      */
 641     protected function find_module($component) {
 642         global $CFG, $PAGE;
 643
 644         $module = null;
 645
 646         if (strpos($component, 'core_') === 0) {
 647             // Must be some core stuff - list here is not complete, this is just the stuff used from multiple places
 648             // so that we do nto have to repeat the definition of these modules over and over again.
 649             switch($component) {
 650                 case 'core_filepicker':
 651                     $module = array('name'     => 'core_filepicker',
 652                                     'fullpath' => '/repository/filepicker.js',
 653                                     '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'),
 654                                     'strings'  => array(array('lastmodified', 'moodle'), array('name', 'moodle'), array('type', 'repository'), array('size', 'repository'),
 655                                                         array('invalidjson', 'repository'), array('error', 'moodle'), array('info', 'moodle'),
 656                                                         array('nofilesattached', 'repository'), array('filepicker', 'repository'), array('logout', 'repository'),
 657                                                         array('nofilesavailable', 'repository'), array('norepositoriesavailable', 'repository'),
 658                                                         array('fileexistsdialogheader', 'repository'), array('fileexistsdialog_editor', 'repository'),
 659                                                         array('fileexistsdialog_filemanager', 'repository'), array('renameto', 'repository'),
 660                                                         array('referencesexist', 'repository'), array('select', 'repository')
 661                                                     ));
 662                     break;
 663                 case 'core_comment':
 664                     $module = array('name'     => 'core_comment',
 665                                     'fullpath' => '/comment/comment.js',
 666                                     'requires' => array('base', 'io-base', 'node', 'json', 'yui2-animation', 'overlay'),
 667                                     'strings' => array(array('confirmdeletecomments', 'admin'), array('yes', 'moodle'), array('no', 'moodle'))
 668                                 );
 669                     break;
 670                 case 'core_role':
 671                     $module = array('name'     => 'core_role',
 672                                     'fullpath' => '/admin/roles/module.js',
 673                                     'requires' => array('node', 'cookie'));
 674                     break;
 675                 case 'core_completion':
 676                     $module = array('name'     => 'core_completion',
 677                                     'fullpath' => '/course/completion.js');
 678                     break;
 679                 case 'core_dock':
 680                     $module = array('name'     => 'core_dock',
 681                                     'fullpath' => '/blocks/dock.js',
 682                                     'requires' => array('base', 'node', 'event-custom', 'event-mouseenter', 'event-resize', 'escape'),
 683                                     'strings'  => array(array('addtodock', 'block'),array('undockitem', 'block'),array('dockblock', 'block'),
 684                                                         array('undockblock', 'block'),array('undockall', 'block'),array('thisdirectionvertical', 'langconfig'),
 685                                                         array('hidedockpanel', 'block'),array('hidepanel', 'block')
 686                                                     ));
 687                     break;
 688                 case 'core_message':
 689                     $module = array('name'     => 'core_message',
 690                                     'requires' => array('base', 'node', 'event', 'node-event-simulate'),
 691                                     'fullpath' => '/message/module.js');
 692                     break;
 693                 case 'core_group':
 694                     $module = array('name'     => 'core_group',
 695                                     'fullpath' => '/group/module.js',
 696                                     'requires' => array('node', 'overlay', 'event-mouseenter'));
 697                     break;
 698                 case 'core_question_engine':
 699                     $module = array('name'     => 'core_question_engine',
 700                                     'fullpath' => '/question/qengine.js',
 701                                     'requires' => array('node', 'event'));
 702                     break;
 703                 case 'core_rating':
 704                     $module = array('name'     => 'core_rating',
 705                                     'fullpath' => '/rating/module.js',
 706                                     'requires' => array('node', 'event', 'overlay', 'io-base', 'json'));
 707                     break;
 708                 case 'core_dndupload':
 709                     $module = array('name'     => 'core_dndupload',
 710                                     'fullpath' => '/lib/form/dndupload.js',
 711                                     'requires' => array('node', 'event', 'json', 'core_filepicker'),
 712                                     'strings'  => array(array('uploadformlimit', 'moodle'), array('droptoupload', 'moodle'), array('maxfilesreached', 'moodle'),
 713                                                         array('dndenabled_inbox', 'moodle'), array('fileexists', 'moodle'), array('maxbytesforfile', 'moodle'),
 714                                                         array('maxareabytesreached', 'moodle')
 715                                                     ));
 716                     break;
 717             }
 718
 719         } else {
 720             if ($dir = get_component_directory($component)) {
 721                 if (file_exists("$dir/module.js")) {
 722                     if (strpos($dir, $CFG->dirroot.'/') === 0) {
 723                         $dir = substr($dir, strlen($CFG->dirroot));
 724                         $module = array('name'=>$component, 'fullpath'=>"$dir/module.js", 'requires' => array());
 725                     }
 726                 }
 727             }
 728         }
 729
 730         return $module;
 731     }
 732
 733     /**
 734      * Append YUI3 module to default YUI3 JS loader.
 735      * The structure of module array is described at {@link http://developer.yahoo.com/yui/3/yui/}
 736      *
 737      * @param string|array $module name of module (details are autodetected), or full module specification as array
 738      * @return void
 739      */
 740     public function js_module($module) {
 741         global $CFG;
 742
 743         if (empty($module)) {
 744             throw new coding_exception('Missing YUI3 module name or full description.');
 745         }
 746
 747         if (is_string($module)) {
 748             $module = $this->find_module($module);
 749         }
 750
 751         if (empty($module) or empty($module['name']) or empty($module['fullpath'])) {
 752             throw new coding_exception('Missing YUI3 module details.');
 753         }
 754
 755         // Don't load this module if we already have, no need to!
 756         if ($this->js_module_loaded($module['name'])) {
 757             if (debugging('', DEBUG_DEVELOPER)) {
 758                 $this->debug_moduleloadstacktraces[$module['name']][] = format_backtrace(debug_backtrace());
 759             }
 760             return;
 761         }
 762
 763         $module['fullpath'] = $this->js_fix_url($module['fullpath'])->out(false);
 764         // Add all needed strings.
 765         if (!empty($module['strings'])) {
 766             foreach ($module['strings'] as $string) {
 767                 $identifier = $string[0];
 768                 $component = isset($string[1]) ? $string[1] : 'moodle';
 769                 $a = isset($string[2]) ? $string[2] : null;
 770                 $this->string_for_js($identifier, $component, $a);
 771             }
 772         }
 773         unset($module['strings']);
 774
 775         // Process module requirements and attempt to load each. This allows
 776         // moodle modules to require each other.
 777         if (!empty($module['requires'])){
 778             foreach ($module['requires'] as $requirement) {
 779                 $rmodule = $this->find_module($requirement);
 780                 if (is_array($rmodule)) {
 781                     $this->js_module($rmodule);
 782                 }
 783             }
 784         }
 785
 786         if ($this->headdone) {
 787             $this->extramodules[$module['name']] = $module;
 788         } else {
 789             $this->YUI_config->add_module_config($module['name'], $module);
 790         }
 791         if (debugging('', DEBUG_DEVELOPER)) {
 792             if (!array_key_exists($module['name'], $this->debug_moduleloadstacktraces)) {
 793                 $this->debug_moduleloadstacktraces[$module['name']] = array();
 794             }
 795             $this->debug_moduleloadstacktraces[$module['name']][] = format_backtrace(debug_backtrace());
 796         }
 797     }
 798
 799     /**
 800      * Returns true if the module has already been loaded.
 801      *
 802      * @param string|array $module
 803      * @return bool True if the module has already been loaded
 804      */
 805     protected function js_module_loaded($module) {
 806         if (is_string($module)) {
 807             $modulename = $module;
 808         } else {
 809             $modulename = $module['name'];
 810         }
 811         return array_key_exists($modulename, $this->YUI_config->modules) ||
 812                array_key_exists($modulename, $this->extramodules);
 813     }
 814
 815     /**
 816      * Returns the stacktraces from loading js modules.
 817      * @return array
 818      */
 819     public function get_loaded_modules() {
 820         return $this->debug_moduleloadstacktraces;
 821     }
 822
 823     /**
 824      * Ensure that the specified CSS file is linked to from this page.
 825      *
 826      * Because stylesheet links must go in the <head> part of the HTML, you must call
 827      * this function before {@link get_head_code()} is called. That normally means before
 828      * the call to print_header. If you call it when it is too late, an exception
 829      * will be thrown.
 830      *
 831      * Even if a particular style sheet is requested more than once, it will only
 832      * be linked to once.
 833      *
 834      * Please note use of this feature is strongly discouraged,
 835      * it is suitable only for places where CSS is submitted directly by teachers.
 836      * (Students must not be allowed to submit any external CSS because it may
 837      * contain embedded javascript!). Example of correct use is mod/data.
 838      *
 839      * @param string $stylesheet The path to the .css file, relative to $CFG->wwwroot.
 840      *   For example:
 841      *      $PAGE->requires->css('mod/data/css.php?d='.$data->id);
 842      */
 843     public function css($stylesheet) {
 844         global $CFG;
 845
 846         if ($this->headdone) {
 847             throw new coding_exception('Cannot require a CSS file after &lt;head> has been printed.', $stylesheet);
 848         }
 849
 850         if ($stylesheet instanceof moodle_url) {
 851             // ok
 852         } else if (strpos($stylesheet, '/') === 0) {
 853             $stylesheet = new moodle_url($CFG->httpswwwroot.$stylesheet);
 854         } else {
 855             throw new coding_exception('Invalid stylesheet parameter.', $stylesheet);
 856         }
 857
 858         $this->cssurls[$stylesheet->out()] = $stylesheet;
 859     }
 860
 861     /**
 862      * Add theme stylesheet to page - do not use from plugin code,
 863      * this should be called only from the core renderer!
 864      *
 865      * @param moodle_url $stylesheet
 866      * @return void
 867      */
 868     public function css_theme(moodle_url $stylesheet) {
 869         $this->cssthemeurls[] = $stylesheet;
 870     }
 871
 872     /**
 873      * Ensure that a skip link to a given target is printed at the top of the <body>.
 874      *
 875      * You must call this function before {@link get_top_of_body_code()}, (if not, an exception
 876      * will be thrown). That normally means you must call this before the call to print_header.
 877      *
 878      * If you ask for a particular skip link to be printed, it is then your responsibility
 879      * to ensure that the appropriate <a name="..."> tag is printed in the body of the
 880      * page, so that the skip link goes somewhere.
 881      *
 882      * Even if a particular skip link is requested more than once, only one copy of it will be output.
 883      *
 884      * @param string $target the name of anchor this link should go to. For example 'maincontent'.
 885      * @param string $linktext The text to use for the skip link. Normally get_string('skipto', 'access', ...);
 886      */
 887     public function skip_link_to($target, $linktext) {
 888         if ($this->topofbodydone) {
 889             debugging('Page header already printed, can not add skip links any more, code needs to be fixed.');
 890             return;
 891         }
 892         $this->skiplinks[$target] = $linktext;
 893     }
 894
 895     /**
 896      * !!!DEPRECATED!!! please use js_init_call() if possible
 897      * Ensure that the specified JavaScript function is called from an inline script
 898      * somewhere on this page.
 899      *
 900      * By default the call will be put in a script tag at the
 901      * end of the page after initialising Y instance, since this gives best page-load
 902      * performance and allows you to use YUI3 library.
 903      *
 904      * If you request that a particular function is called several times, then
 905      * that is what will happen (unlike linking to a CSS or JS file, where only
 906      * one link will be output).
 907      *
 908      * The main benefit of the method is the automatic encoding of all function parameters.
 909      *
 910      * @deprecated
 911      *
 912      * @param string $function the name of the JavaScritp function to call. Can
 913      *      be a compound name like 'Y.Event.purgeElement'. Can also be
 914      *      used to create and object by using a 'function name' like 'new user_selector'.
 915      * @param array $arguments and array of arguments to be passed to the function.
 916      *      When generating the function call, this will be escaped using json_encode,
 917      *      so passing objects and arrays should work.
 918      * @param bool $ondomready If tru the function is only called when the dom is
 919      *      ready for manipulation.
 920      * @param int $delay The delay before the function is called.
 921      */
 922     public function js_function_call($function, array $arguments = null, $ondomready = false, $delay = 0) {
 923         $where = $ondomready ? 'ondomready' : 'normal';
 924         $this->jscalls[$where][] = array($function, $arguments, $delay);
 925     }
 926
 927     /**
 928      * Adds a call to make use of a YUI gallery module. DEPRECATED DO NOT USE!!!
 929      *
 930      * @deprecated DO NOT USE
 931      *
 932      * @param string|array $modules One or more gallery modules to require
 933      * @param string $version
 934      * @param string $function
 935      * @param array $arguments
 936      * @param bool $ondomready
 937      */
 938     public function js_gallery_module($modules, $version, $function, array $arguments = null, $ondomready = false) {
 939         global $CFG;
 940         debugging('This function will be removed before 2.0 is released please change it from js_gallery_module to yui_module', DEBUG_DEVELOPER);
 941         $this->yui_module($modules, $function, $arguments, $version, $ondomready);
 942     }
 943
 944     /**
 945      * Creates a JavaScript function call that requires one or more modules to be loaded.
 946      *
 947      * This function can be used to include all of the standard YUI module types within JavaScript:
 948      *     - YUI3 modules    [node, event, io]
 949      *     - YUI2 modules    [yui2-*]
 950      *     - Moodle modules  [moodle-*]
 951      *     - Gallery modules [gallery-*]
 952      *
 953      * @param array|string $modules One or more modules
 954      * @param string $function The function to call once modules have been loaded
 955      * @param array $arguments An array of arguments to pass to the function
 956      * @param string $galleryversion The gallery version to use
 957      * @param bool $ondomready
 958      */
 959     public function yui_module($modules, $function, array $arguments = null, $galleryversion = null, $ondomready = false) {
 960         global $CFG;
 961
 962         if (!$galleryversion) {
 963             $galleryversion = '2010.04.08-12-35';
 964         }
 965
 966         if (!is_array($modules)) {
 967             $modules = array($modules);
 968         }
 969         if (empty($CFG->useexternalyui)) {
 970             // We need to set the M.yui.galleryversion to the correct version
 971             $jscode = 'M.yui.galleryversion='.json_encode($galleryversion).';';
 972         } else {
 973             // Set Y's config.gallery to the version
 974             $jscode = 'Y.config.gallery='.json_encode($galleryversion).';';
 975         }
 976         $jscode .= 'Y.use('.join(',', array_map('json_encode', convert_to_array($modules))).',function() {'.js_writer::function_call($function, $arguments).'});';
 977         if ($ondomready) {
 978             $jscode = "Y.on('domready', function() { $jscode });";
 979         }
 980         $this->jsinitcode[] = $jscode;
 981     }
 982
 983     /**
 984      * Ensure that the specified JavaScript function is called from an inline script
 985      * from page footer.
 986      *
 987      * @param string $function the name of the JavaScritp function to with init code,
 988      *      usually something like 'M.mod_mymodule.init'
 989      * @param array $extraarguments and array of arguments to be passed to the function.
 990      *      The first argument is always the YUI3 Y instance with all required dependencies
 991      *      already loaded.
 992      * @param bool $ondomready wait for dom ready (helps with some IE problems when modifying DOM)
 993      * @param array $module JS module specification array
 994      */
 995     public function js_init_call($function, array $extraarguments = null, $ondomready = false, array $module = null) {
 996         $jscode = js_writer::function_call_with_Y($function, $extraarguments);
 997         if (!$module) {
 998             // Detect module automatically.
 999             if (preg_match('/M\.([a-z0-9]+_[^\.]+)/', $function, $matches)) {
1000                 $module = $this->find_module($matches[1]);
1001             }
1002         }
1003
1004         $this->js_init_code($jscode, $ondomready, $module);
1005     }
1006
1007     /**
1008      * Add short static javascript code fragment to page footer.
1009      * This is intended primarily for loading of js modules and initialising page layout.
1010      * Ideally the JS code fragment should be stored in plugin renderer so that themes
1011      * may override it.
1012      *
1013      * @param string $jscode
1014      * @param bool $ondomready wait for dom ready (helps with some IE problems when modifying DOM)
1015      * @param array $module JS module specification array
1016      */
1017     public function js_init_code($jscode, $ondomready = false, array $module = null) {
1018         $jscode = trim($jscode, " ;\n"). ';';
1019
1020         if ($module) {
1021             $this->js_module($module);
1022             $modulename = $module['name'];
1023             $jscode = "Y.use('$modulename', function(Y) { $jscode });";
1024         }
1025
1026         if ($ondomready) {
1027             $jscode = "Y.on('domready', function() { $jscode });";
1028         }
1029
1030         $this->jsinitcode[] = $jscode;
1031     }
1032
1033     /**
1034      * Make a language string available to JavaScript.
1035      *
1036      * All the strings will be available in a M.str object in the global namespace.
1037      * So, for example, after a call to $PAGE->requires->string_for_js('course', 'moodle');
1038      * then the JavaScript variable M.str.moodle.course will be 'Course', or the
1039      * equivalent in the current language.
1040      *
1041      * The arguments to this function are just like the arguments to get_string
1042      * except that $component is not optional, and there are some aspects to consider
1043      * when the string contains {$a} placeholder.
1044      *
1045      * If the string does not contain any {$a} placeholder, you can simply use
1046      * M.str.component.identifier to obtain it. If you prefer, you can call
1047      * M.util.get_string(identifier, component) to get the same result.
1048      *
1049      * If you need to use {$a} placeholders, there are two options. Either the
1050      * placeholder should be substituted in PHP on server side or it should
1051      * be substituted in Javascript at client side.
1052      *
1053      * To substitute the placeholder at server side, just provide the required
1054      * value for the placeholder when you require the string. Because each string
1055      * is only stored once in the JavaScript (based on $identifier and $module)
1056      * you cannot get the same string with two different values of $a. If you try,
1057      * an exception will be thrown. Once the placeholder is substituted, you can
1058      * use M.str or M.util.get_string() as shown above:
1059      *
1060      *     // Require the string in PHP and replace the placeholder.
1061      *     $PAGE->requires->string_for_js('fullnamedisplay', 'moodle', $USER);
1062      *     // Use the result of the substitution in Javascript.
1063      *     alert(M.str.moodle.fullnamedisplay);
1064      *
1065      * To substitute the placeholder at client side, use M.util.get_string()
1066      * function. It implements the same logic as {@link get_string()}:
1067      *
1068      *     // Require the string in PHP but keep {$a} as it is.
1069      *     $PAGE->requires->string_for_js('fullnamedisplay', 'moodle');
1070      *     // Provide the values on the fly in Javascript.
1071      *     user = { firstname : 'Harry', lastname : 'Potter' }
1072      *     alert(M.util.get_string('fullnamedisplay', 'moodle', user);
1073      *
1074      * If you do need the same string expanded with different $a values in PHP
1075      * on server side, then the solution is to put them in your own data structure
1076      * (e.g. and array) that you pass to JavaScript with {@link data_for_js()}.
1077      *
1078      * @param string $identifier the desired string.
1079      * @param string $component the language file to look in.
1080      * @param mixed $a any extra data to add into the string (optional).
1081      */
1082     public function string_for_js($identifier, $component, $a = null) {
1083         if (!$component) {
1084             throw new coding_exception('The $component parameter is required for page_requirements_manager::string_for_js().');
1085         }
1086         if (isset($this->stringsforjs_as[$component][$identifier]) and $this->stringsforjs_as[$component][$identifier] !== $a) {
1087             throw new coding_exception("Attempt to re-define already required string '$identifier' " .
1088                     "from lang file '$component' with different \$a parameter?");
1089         }
1090         if (!isset($this->stringsforjs[$component][$identifier])) {
1091             $this->stringsforjs[$component][$identifier] = new lang_string($identifier, $component, $a);
1092             $this->stringsforjs_as[$component][$identifier] = $a;
1093         }
1094     }
1095
1096     /**
1097      * Make an array of language strings available for JS.
1098      *
1099      * This function calls the above function {@link string_for_js()} for each requested
1100      * string in the $identifiers array that is passed to the argument for a single module
1101      * passed in $module.
1102      *
1103      * <code>
1104      * $PAGE->requires->strings_for_js(array('one', 'two', 'three'), 'mymod', array('a', null, 3));
1105      *
1106      * // The above is identical to calling:
1107      *
1108      * $PAGE->requires->string_for_js('one', 'mymod', 'a');
1109      * $PAGE->requires->string_for_js('two', 'mymod');
1110      * $PAGE->requires->string_for_js('three', 'mymod', 3);
1111      * </code>
1112      *
1113      * @param array $identifiers An array of desired strings
1114      * @param string $component The module to load for
1115      * @param mixed $a This can either be a single variable that gets passed as extra
1116      *         information for every string or it can be an array of mixed data where the
1117      *         key for the data matches that of the identifier it is meant for.
1118      *
1119      */
1120     public function strings_for_js($identifiers, $component, $a = null) {
1121         foreach ($identifiers as $key => $identifier) {
1122             if (is_array($a) && array_key_exists($key, $a)) {
1123                 $extra = $a[$key];
1124             } else {
1125                 $extra = $a;
1126             }
1127             $this->string_for_js($identifier, $component, $extra);
1128         }
1129     }
1130
1131     /**
1132      * !!!!!!DEPRECATED!!!!!! please use js_init_call() for everything now.
1133      *
1134      * Make some data from PHP available to JavaScript code.
1135      *
1136      * For example, if you call
1137      * <pre>
1138      *      $PAGE->requires->data_for_js('mydata', array('name' => 'Moodle'));
1139      * </pre>
1140      * then in JavsScript mydata.name will be 'Moodle'.
1141      *
1142      * @deprecated
1143      * @param string $variable the the name of the JavaScript variable to assign the data to.
1144      *      Will probably work if you use a compound name like 'mybuttons.button[1]', but this
1145      *      should be considered an experimental feature.
1146      * @param mixed $data The data to pass to JavaScript. This will be escaped using json_encode,
1147      *      so passing objects and arrays should work.
1148      * @param bool $inhead initialise in head
1149      * @return void
1150      */
1151     public function data_for_js($variable, $data, $inhead=false) {
1152         $where = $inhead ? 'head' : 'footer';
1153         $this->jsinitvariables[$where][] = array($variable, $data);
1154     }
1155
1156     /**
1157      * Creates a YUI event handler.
1158      *
1159      * @param mixed $selector standard YUI selector for elements, may be array or string, element id is in the form "#idvalue"
1160      * @param string $event A valid DOM event (click, mousedown, change etc.)
1161      * @param string $function The name of the function to call
1162      * @param array  $arguments An optional array of argument parameters to pass to the function
1163      */
1164     public function event_handler($selector, $event, $function, array $arguments = null) {
1165         $this->eventhandlers[] = array('selector'=>$selector, 'event'=>$event, 'function'=>$function, 'arguments'=>$arguments);
1166     }
1167
1168     /**
1169      * Returns code needed for registering of event handlers.
1170      * @return string JS code
1171      */
1172     protected function get_event_handler_code() {
1173         $output = '';
1174         foreach ($this->eventhandlers as $h) {
1175             $output .= js_writer::event_handler($h['selector'], $h['event'], $h['function'], $h['arguments']);
1176         }
1177         return $output;
1178     }
1179
1180     /**
1181      * Get the inline JavaScript code that need to appear in a particular place.
1182      * @param bool $ondomready
1183      * @return string
1184      */
1185     protected function get_javascript_code($ondomready) {
1186         $where = $ondomready ? 'ondomready' : 'normal';
1187         $output = '';
1188         if ($this->jscalls[$where]) {
1189             foreach ($this->jscalls[$where] as $data) {
1190                 $output .= js_writer::function_call($data[0], $data[1], $data[2]);
1191             }
1192             if (!empty($ondomready)) {
1193                 $output = "    Y.on('domready', function() {\n$output\n    });";
1194             }
1195         }
1196         return $output;
1197     }
1198
1199     /**
1200      * Returns js code to be executed when Y is available.
1201      * @return string
1202      */
1203     protected function get_javascript_init_code() {
1204         if (count($this->jsinitcode)) {
1205             return implode("\n", $this->jsinitcode) . "\n";
1206         }
1207         return '';
1208     }
1209
1210     /**
1211      * Returns basic YUI3 JS loading code.
1212      * YUI3 is using autoloading of both CSS and JS code.
1213      *
1214      * Major benefit of this compared to standard js/csss loader is much improved
1215      * caching, better browser cache utilisation, much fewer http requests.
1216      *
1217      * @param moodle_page $page
1218      * @return string
1219      */
1220     protected function get_yui3lib_headcode($page) {
1221         global $CFG;
1222
1223         $code = '';
1224
1225         if ($this->yui3loader->combine) {
1226             if (!empty($page->theme->yuicssmodules)) {
1227                 $modules = array();
1228                 foreach ($page->theme->yuicssmodules as $module) {
1229                     $modules[] = "$CFG->yui3version/build/$module/$module-min.css";
1230                 }
1231                 $code .= '<link rel="stylesheet" type="text/css" href="'.$this->yui3loader->comboBase.implode('&amp;', $modules).'" />';
1232             }
1233             $code .= '<script type="text/javascript" src="'.$this->yui3loader->comboBase
1234                      .$CFG->yui3version.'/build/simpleyui/simpleyui-min.js&amp;'
1235                      .$CFG->yui3version.'/build/loader/loader-min.js"></script>';
1236         } else {
1237             if (!empty($page->theme->yuicssmodules)) {
1238                 foreach ($page->theme->yuicssmodules as $module) {
1239                     $code .= '<link rel="stylesheet" type="text/css" href="'.$this->yui3loader->base.$module.'/'.$module.'-min.css" />';
1240                 }
1241             }
1242             $code .= '<script type="text/javascript" src="'.$this->yui3loader->base.'simpleyui/simpleyui-min.js"></script>';
1243             $code .= '<script type="text/javascript" src="'.$this->yui3loader->base.'loader/loader-min.js"></script>';
1244         }
1245
1246
1247         if ($this->yui3loader->filter === 'RAW') {
1248             $code = str_replace('-min.css', '.css', $code);
1249             $code = str_replace('-min.js', '.js', $code);
1250         } else if ($this->yui3loader->filter === 'DEBUG') {
1251             $code = str_replace('-min.css', '.css', $code);
1252             $code = str_replace('-min.js', '-debug.js', $code);
1253         }
1254
1255         return $code;
1256     }
1257
1258     /**
1259      * Returns html tags needed for inclusion of theme CSS.
1260      *
1261      * @return string
1262      */
1263     protected function get_css_code() {
1264         // First of all the theme CSS, then any custom CSS
1265         // Please note custom CSS is strongly discouraged,
1266         // because it can not be overridden by themes!
1267         // It is suitable only for things like mod/data which accepts CSS from teachers.
1268         $attributes = array('rel'=>'stylesheet', 'type'=>'text/css');
1269
1270         // This line of code may look funny but it is currently required in order
1271         // to avoid MASSIVE display issues in Internet Explorer.
1272         // As of IE8 + YUI3.1.1 the reference stylesheet (firstthemesheet) gets
1273         // ignored whenever another resource is added until such time as a redraw
1274         // is forced, usually by moving the mouse over the affected element.
1275         $code = html_writer::tag('script', '/** Required in order to fix style inclusion problems in IE with YUI **/', array('id'=>'firstthemesheet', 'type'=>'text/css'));
1276
1277         $urls = $this->cssthemeurls + $this->cssurls;
1278         foreach ($urls as $url) {
1279             $attributes['href'] = $url;
1280             $code .= html_writer::empty_tag('link', $attributes) . "\n";
1281             // This id is needed in first sheet only so that theme may override YUI sheets loaded on the fly.
1282             unset($attributes['id']);
1283         }
1284
1285         return $code;
1286     }
1287
1288     /**
1289      * Adds extra modules specified after printing of page header.
1290      *
1291      * @return string
1292      */
1293     protected function get_extra_modules_code() {
1294         if (empty($this->extramodules)) {
1295             return '';
1296         }
1297         return html_writer::script(js_writer::function_call('M.yui.add_module', array($this->extramodules)));
1298     }
1299
1300     /**
1301      * Generate any HTML that needs to go inside the <head> tag.
1302      *
1303      * Normally, this method is called automatically by the code that prints the
1304      * <head> tag. You should not normally need to call it in your own code.
1305      *
1306      * @param moodle_page $page
1307      * @param core_renderer $renderer
1308      * @return string the HTML code to to inside the <head> tag.
1309      */
1310     public function get_head_code(moodle_page $page, core_renderer $renderer) {
1311         global $CFG;
1312
1313         // Note: the $page and $output are not stored here because it would
1314         // create circular references in memory which prevents garbage collection.
1315         $this->init_requirements_data($page, $renderer);
1316
1317         $output = '';
1318
1319         // Set up the M namespace.
1320         $js = "var M = {}; M.yui = {};\n";
1321
1322         // Capture the time now ASAP during page load. This minimises the lag when
1323         // we try to relate times on the server to times in the browser.
1324         // An example of where this is used is the quiz countdown timer.
1325         $js .= "M.pageloadstarttime = new Date();\n";
1326
1327         // Add a subset of Moodle configuration to the M namespace.
1328         $js .= js_writer::set_variable('M.cfg', $this->M_cfg, false);
1329
1330         // Set up global YUI3 loader object - this should contain all code needed by plugins.
1331         // Note: in JavaScript just use "YUI().use('overlay', function(Y) { .... });",
1332         //       this needs to be done before including any other script.
1333         $js .= $this->YUI_config->get_config_functions();
1334         $js .= js_writer::set_variable('YUI_config', $this->YUI_config, false) . "\n";
1335         $js .= "M.yui.loader = {modules: {}};\n"; // Backwards compatibility only, not used any more.
1336         $js = $this->YUI_config->update_header_js($js);
1337
1338         $output .= html_writer::script($js);
1339
1340         // YUI3 JS and CSS need to be loaded in the header but after the YUI_config has been created.
1341         // They should be cached well by the browser.
1342         $output .= $this->get_yui3lib_headcode($page);
1343
1344         // Add hacked jQuery support, it is not intended for standard Moodle distribution!
1345         $output .= $this->get_jquery_headcode();
1346
1347         // Now theme CSS + custom CSS in this specific order.
1348         $output .= $this->get_css_code();
1349
1350         // Link our main JS file, all core stuff should be there.
1351         $output .= html_writer::script('', $this->js_fix_url('/lib/javascript-static.js'));
1352
1353         // Add variables.
1354         if ($this->jsinitvariables['head']) {
1355             $js = '';
1356             foreach ($this->jsinitvariables['head'] as $data) {
1357                 list($var, $value) = $data;
1358                 $js .= js_writer::set_variable($var, $value, true);
1359             }
1360             $output .= html_writer::script($js);
1361         }
1362
1363         // All the other linked things from HEAD - there should be as few as possible.
1364         if ($this->jsincludes['head']) {
1365             foreach ($this->jsincludes['head'] as $url) {
1366                 $output .= html_writer::script('', $url);
1367             }
1368         }
1369
1370         // Mark head sending done, it is not possible to anything there.
1371         $this->headdone = true;
1372
1373         return $output;
1374     }
1375
1376     /**
1377      * Generate any HTML that needs to go at the start of the <body> tag.
1378      *
1379      * Normally, this method is called automatically by the code that prints the
1380      * <head> tag. You should not normally need to call it in your own code.
1381      *
1382      * @return string the HTML code to go at the start of the <body> tag.
1383      */
1384     public function get_top_of_body_code() {
1385         // First the skip links.
1386         $links = '';
1387         $attributes = array('class'=>'skip');
1388         foreach ($this->skiplinks as $url => $text) {
1389             $attributes['href'] = '#' . $url;
1390             $links .= html_writer::tag('a', $text, $attributes);
1391         }
1392         $output = html_writer::tag('div', $links, array('class'=>'skiplinks')) . "\n";
1393
1394         // Then the clever trick for hiding of things not needed when JS works.
1395         $output .= html_writer::script("document.body.className += ' jsenabled';") . "\n";
1396         $this->topofbodydone = true;
1397         return $output;
1398     }
1399
1400     /**
1401      * Generate any HTML that needs to go at the end of the page.
1402      *
1403      * Normally, this method is called automatically by the code that prints the
1404      * page footer. You should not normally need to call it in your own code.
1405      *
1406      * @return string the HTML code to to at the end of the page.
1407      */
1408     public function get_end_code() {
1409         global $CFG;
1410
1411         // Add other requested modules.
1412         $output = $this->get_extra_modules_code();
1413
1414         // All the other linked scripts - there should be as few as possible.
1415         if ($this->jsincludes['footer']) {
1416             foreach ($this->jsincludes['footer'] as $url) {
1417                 $output .= html_writer::script('', $url);
1418             }
1419         }
1420
1421         // Add all needed strings.
1422         if (!empty($this->stringsforjs)) {
1423             $strings = array();
1424             foreach ($this->stringsforjs as $component=>$v) {
1425                 foreach($v as $indentifier => $langstring) {
1426                     $strings[$component][$indentifier] = $langstring->out();
1427                 }
1428             }
1429             $output .= html_writer::script(js_writer::set_variable('M.str', $strings));
1430         }
1431
1432         // Add variables.
1433         if ($this->jsinitvariables['footer']) {
1434             $js = '';
1435             foreach ($this->jsinitvariables['footer'] as $data) {
1436                 list($var, $value) = $data;
1437                 $js .= js_writer::set_variable($var, $value, true);
1438             }
1439             $output .= html_writer::script($js);
1440         }
1441
1442         $inyuijs = $this->get_javascript_code(false);
1443         $ondomreadyjs = $this->get_javascript_code(true);
1444         $jsinit = $this->get_javascript_init_code();
1445         $handlersjs = $this->get_event_handler_code();
1446
1447         // There is no global Y, make sure it is available in your scope.
1448         $js = "YUI().use('node', function(Y) {\n{$inyuijs}{$ondomreadyjs}{$jsinit}{$handlersjs}\n});";
1449
1450         $output .= html_writer::script($js);
1451
1452         return $output;
1453     }
1454
1455     /**
1456      * Have we already output the code in the <head> tag?
1457      *
1458      * @return bool
1459      */
1460     public function is_head_done() {
1461         return $this->headdone;
1462     }
1463
1464     /**
1465      * Have we already output the code at the start of the <body> tag?
1466      *
1467      * @return bool
1468      */
1469     public function is_top_of_body_done() {
1470         return $this->topofbodydone;
1471     }
1472 }
1473
1474 /**
1475  * This class represents the YUI configuration.
1476  *
1477  * @copyright 2013 Andrew Nicols
1478  * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
1479  * @since Moodle 2.5
1480  * @package core
1481  * @category output
1482  */
1483 class YUI_config {
1484     /**
1485      * These settings must be public so that when the object is converted to json they are exposed.
1486      * Note: Some of these are camelCase because YUI uses camelCase variable names.
1487      *
1488      * The settings are described and documented in the YUI API at:
1489      * - http://yuilibrary.com/yui/docs/api/classes/config.html
1490      * - http://yuilibrary.com/yui/docs/api/classes/Loader.html
1491      */
1492     public $debug = false;
1493     public $base;
1494     public $comboBase;
1495     public $combine;
1496     public $filter = null;
1497     public $insertBefore = 'firstthemesheet';
1498     public $groups = array();
1499     public $modules = array();
1500
1501     /**
1502      * @var array List of functions used by the YUI Loader group pattern recognition.
1503      */
1504     protected $jsconfigfunctions = array();
1505
1506     /**
1507      * Create a new group within the YUI_config system.
1508      *
1509      * @param String $name The name of the group. This must be unique and
1510      * not previously used.
1511      * @param Array $config The configuration for this group.
1512      * @return void
1513      */
1514     public function add_group($name, $config) {
1515         if (isset($this->groups[$name])) {
1516             throw new coding_exception("A YUI configuration group for '{$name}' already exists. To make changes to this group use YUI_config->update_group().");
1517         }
1518         $this->groups[$name] = $config;
1519     }
1520
1521     /**
1522      * Update an existing group configuration
1523      *
1524      * Note, any existing configuration for that group will be wiped out.
1525      * This includes module configuration.
1526      *
1527      * @param String $name The name of the group. This must be unique and
1528      * not previously used.
1529      * @param Array $config The configuration for this group.
1530      * @return void
1531      */
1532     public function update_group($name, $config) {
1533         if (!isset($this->groups[$name])) {
1534             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.');
1535         }
1536         $this->groups[$name] = $config;
1537     }
1538
1539     /**
1540      * Set the value of a configuration function used by the YUI Loader's pattern testing.
1541      *
1542      * Only the body of the function should be passed, and not the whole function wrapper.
1543      *
1544      * The JS function your write will be passed a single argument 'name' containing the
1545      * name of the module being loaded.
1546      *
1547      * @param $function String the body of the JavaScript function. This should be used i
1548      * @return String the name of the function to use in the group pattern configuration.
1549      */
1550     public function set_config_function($function) {
1551         $configname = 'yui' . (count($this->jsconfigfunctions) + 1) . 'ConfigFn';
1552         if (isset($this->jsconfigfunctions[$configname])) {
1553             throw new coding_exception("A YUI config function with this name already exists. Config function names must be unique.");
1554         }
1555         $this->jsconfigfunctions[$configname] = $function;
1556         return '@' . $configname . '@';
1557     }
1558
1559     /**
1560      * Retrieve the list of JavaScript functions for YUI_config groups.
1561      *
1562      * @return String The complete set of config functions
1563      */
1564     public function get_config_functions() {
1565         $configfunctions = '';
1566         foreach ($this->jsconfigfunctions as $functionname => $function) {
1567             $configfunctions .= "var {$functionname} = function(me) {";
1568             $configfunctions .= $function;
1569             $configfunctions .= "};\n";
1570         }
1571         return $configfunctions;
1572     }
1573
1574     /**
1575      * Update the header JavaScript with any required modification for the YUI Loader.
1576      *
1577      * @param $js String The JavaScript to manipulate.
1578      * @return String the modified JS string.
1579      */
1580     public function update_header_js($js) {
1581         // Update the names of the the configFn variables.
1582         // The PHP json_encode function cannot handle literal names so we have to wrap
1583         // them in @ and then replace them with literals of the same function name.
1584         foreach ($this->jsconfigfunctions as $functionname => $function) {
1585             $js = str_replace('"@' . $functionname . '@"', $functionname, $js);
1586         }
1587         return $js;
1588     }
1589
1590     /**
1591      * Add configuration for a specific module.
1592      *
1593      * @param String $name The name of the module to add configuration for.
1594      * @param Array $config The configuration for the specified module.
1595      * @param String $group The name of the group to add configuration for.
1596      * If not specified, then this module is added to the global
1597      * configuration.
1598      * @return void
1599      */
1600     public function add_module_config($name, $config, $group = null) {
1601         if ($group) {
1602             if (!isset($this->groups[$name])) {
1603                 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.');
1604             }
1605             if (!isset($this->groups[$group]['modules'])) {
1606                 $this->groups[$group]['modules'] = array();
1607             }
1608             $modules = &$this->groups[$group]['modules'];
1609         } else {
1610             $modules = &$this->modules;
1611         }
1612         $modules[$name] = $config;
1613     }
1614
1615     /**
1616      * Add the moodle YUI module metadata for the moodle group to the YUI_config instance.
1617      *
1618      * If js caching is disabled, metadata will not be served causing YUI to calculate
1619      * module dependencies as each module is loaded.
1620      *
1621      * If metadata does not exist it will be created and stored in a MUC entry.
1622      *
1623      * @return void
1624      */
1625     public function add_moodle_metadata() {
1626         global $CFG;
1627         if (!isset($this->groups['moodle'])) {
1628             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.');
1629         }
1630
1631         if (!isset($this->groups['moodle']['modules'])) {
1632             $this->groups['moodle']['modules'] = array();
1633         }
1634
1635         $cache = cache::make('core', 'yuimodules');
1636         if (!isset($CFG->jsrev) || $CFG->jsrev == -1) {
1637             $metadata = array();
1638             $cache->delete('metadata');
1639         } else {
1640             // Attempt to get the metadata from the cache.
1641             if (!$metadata = $cache->get('metadata')) {
1642                 $metadata = $this->get_moodle_metadata();
1643                 $cache->set('metadata', $metadata);
1644             }
1645         }
1646
1647         // Merge with any metadata added specific to this page which was added manually.
1648         $this->groups['moodle']['modules'] = array_merge($this->groups['moodle']['modules'],
1649                 $metadata);
1650     }
1651
1652     /**
1653      * Determine the module metadata for all moodle YUI modules.
1654      *
1655      * This works through all modules capable of serving YUI modules, and attempts to get
1656      * metadata for each of those modules.
1657      *
1658      * @return Array of module metadata
1659      */
1660     private function get_moodle_metadata() {
1661         $moodlemodules = array();
1662         // Core isn't a plugin type or subsystem - handle it seperately.
1663         if ($module = $this->get_moodle_path_metadata(get_component_directory('core'))) {
1664             $moodlemodules = array_merge($moodlemodules, $module);
1665         }
1666
1667         // Handle other core subsystems.
1668         $subsystems = get_core_subsystems();
1669         foreach ($subsystems as $subsystem => $path) {
1670             if (is_null($path)) {
1671                 continue;
1672             }
1673             $path = get_component_directory($subsystem);
1674             if ($module = $this->get_moodle_path_metadata($path)) {
1675                 $moodlemodules = array_merge($moodlemodules, $module);
1676             }
1677         }
1678
1679         // And finally the plugins.
1680         $plugintypes = get_plugin_types();
1681         foreach ($plugintypes as $plugintype => $pathroot) {
1682             $pluginlist = get_plugin_list($plugintype);
1683             foreach ($pluginlist as $plugin => $path) {
1684                 if ($module = $this->get_moodle_path_metadata($path)) {
1685                     $moodlemodules = array_merge($moodlemodules, $module);
1686                 }
1687             }
1688         }
1689
1690         return $moodlemodules;
1691     }
1692
1693     /**
1694      * Helper function process and return the YUI metadata for all of the modules under the specified path.
1695      *
1696      * @param String $path the UNC path to the YUI src directory.
1697      * @return Array the complete array for frankenstyle directory.
1698      */
1699     private function get_moodle_path_metadata($path) {
1700         // Add module metadata is stored in frankenstyle_modname/yui/src/yui_modname/meta/yui_modname.json.
1701         $baseyui = $path . '/yui/src';
1702         $modules = array();
1703         if (is_dir($baseyui)) {
1704             $items = new DirectoryIterator($baseyui);
1705             foreach ($items as $item) {
1706                 if ($item->isDot() or !$item->isDir()) {
1707                     continue;
1708                 }
1709                 $metafile = realpath($baseyui . '/' . $item . '/meta/' . $item . '.json');
1710                 if (!is_readable($metafile)) {
1711                     continue;
1712                 }
1713                 $metadata = file_get_contents($metafile);
1714                 $modules = array_merge($modules, (array) json_decode($metadata));
1715             }
1716         }
1717         return $modules;
1718     }
1719 }
1720
1721 /**
1722  * Invalidate all server and client side JS caches.
1723  */
1724 function js_reset_all_caches() {
1725     global $CFG;
1726     require_once("$CFG->libdir/filelib.php");
1727
1728     $next = time();
1729     if (isset($CFG->jsrev) and $next <= $CFG->jsrev and $CFG->jsrev - $next < 60*60) {
1730         // This resolves problems when reset is requested repeatedly within 1s,
1731         // the < 1h condition prevents accidental switching to future dates
1732         // because we might not recover from it.
1733         $next = $CFG->jsrev+1;
1734     }
1735
1736     set_config('jsrev', $next);
1737     fulldelete("$CFG->cachedir/js");
1738 }