lib/pagelib.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  * This file contains the moodle_page class. There is normally a single instance
  19  * of this class in the $PAGE global variable. This class is a central repository
  20  * of information about the page we are building up to send back to the user.
  21  *
  22  * @package core
  23  * @category page
  24  * @copyright  1999 onwards Martin Dougiamas  {@link http://moodle.com}
  25  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  26  */
  27
  28 defined('MOODLE_INTERNAL') || die();
  29
  30 /**
  31  * $PAGE is a central store of information about the current page we are
  32  * generating in response to the user's request.
  33  *
  34  * It does not do very much itself
  35  * except keep track of information, however, it serves as the access point to
  36  * some more significant components like $PAGE->theme, $PAGE->requires,
  37  * $PAGE->blocks, etc.
  38  *
  39  * @copyright 2009 Tim Hunt
  40  * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  41  * @since Moodle 2.0
  42  * @package core
  43  * @category page
  44  *
  45  * The following properties are alphabetical. Please keep it that way so that its
  46  * easy to maintain.
  47  *
  48  * @property-read string $activityname The type of activity we are in, for example 'forum' or 'quiz'.
  49  *      Will be null if this page is not within a module.
  50  * @property-read stdClass $activityrecord The row from the activities own database table (for example
  51  *      the forum or quiz table) that this page belongs to. Will be null
  52  *      if this page is not within a module.
  53  * @property-read array $alternativeversions Mime type => object with ->url and ->title.
  54  * @property-read blocks_manager $blocks The blocks manager object for this page.
  55  * @property-read string $bodyclasses A string to use within the class attribute on the body tag.
  56  * @property-read string $bodyid A string to use as the id of the body tag.
  57  * @property-read string $button The HTML to go where the Turn editing on button normally goes.
  58  * @property-read bool $cacheable Defaults to true. Set to false to stop the page being cached at all.
  59  * @property-read array $categories An array of all the categories the page course belongs to,
  60  *      starting with the immediately containing category, and working out to
  61  *      the top-level category. This may be the empty array if we are in the
  62  *      front page course.
  63  * @property-read mixed $category The category that the page course belongs to.
  64  * @property-read cm_info $cm The course_module that this page belongs to. Will be null
  65  *      if this page is not within a module. This is a full cm object, as loaded
  66  *      by get_coursemodule_from_id or get_coursemodule_from_instance,
  67  *      so the extra modname and name fields are present.
  68  * @property-read context $context The main context to which this page belongs.
  69  * @property-read stdClass $course The current course that we are inside - a row from the
  70  *      course table. (Also available as $COURSE global.) If we are not inside
  71  *      an actual course, this will be the site course.
  72  * @property-read string $devicetypeinuse The name of the device type in use
  73  * @property-read string $docspath The path to the Moodle docs for this page.
  74  * @property-read string $focuscontrol The id of the HTML element to be focused when the page has loaded.
  75  * @property-read bool $headerprinted True if the page header has already been printed.
  76  * @property-read string $heading The main heading that should be displayed at the top of the <body>.
  77  * @property-read string $headingmenu The menu (or actions) to display in the heading
  78  * @property-read array $layout_options An arrays with options for the layout file.
  79  * @property-read array $legacythemeinuse True if the legacy browser theme is in use.
  80  * @property-read navbar $navbar The navbar object used to display the navbar
  81  * @property-read global_navigation $navigation The navigation structure for this page.
  82  * @property-read xml_container_stack $opencontainers Tracks XHTML tags on this page that have been opened but not closed.
  83  *      mainly for internal use by the rendering code.
  84  * @property-read string $pagelayout The general type of page this is. For example 'normal', 'popup', 'home'.
  85  *      Allows the theme to display things differently, if it wishes to.
  86  * @property-read string $pagetype The page type string, should be used as the id for the body tag in the theme.
  87  * @property-read int $periodicrefreshdelay The periodic refresh delay to use with meta refresh
  88  * @property-read page_requirements_manager $requires Tracks the JavaScript, CSS files, etc. required by this page.
  89  * @property-read settings_navigation $settingsnav The settings navigation
  90  * @property-read int $state One of the STATE_... constants
  91  * @property-read string $subpage The subpage identifier, if any.
  92  * @property-read theme_config $theme The theme for this page.
  93  * @property-read string $title The title that should go in the <head> section of the HTML of this page.
  94  * @property-read moodle_url $url The moodle url object for this page.
  95  */
  96 class moodle_page {
  97
  98     /** The state of the page before it has printed the header **/
  99     const STATE_BEFORE_HEADER = 0;
 100
 101     /** The state the page is in temporarily while the header is being printed **/
 102     const STATE_PRINTING_HEADER = 1;
 103
 104     /** The state the page is in while content is presumably being printed **/
 105     const STATE_IN_BODY = 2;
 106
 107     /**
 108      * The state the page is when the footer has been printed and its function is
 109      * complete.
 110      */
 111     const STATE_DONE = 3;
 112
 113     /**
 114      * @var int The current state of the page. The state a page is within
 115      * determines what actions are possible for it.
 116      */
 117     protected $_state = self::STATE_BEFORE_HEADER;
 118
 119     /**
 120      * @var stdClass The course currently associated with this page.
 121      * If not has been provided the front page course is used.
 122      */
 123     protected $_course = null;
 124
 125     /**
 126      * @var cm_info If this page belongs to a module, this is the cm_info module
 127      * description object.
 128      */
 129     protected $_cm = null;
 130
 131     /**
 132      * @var stdClass If $_cm is not null, then this will hold the corresponding
 133      * row from the modname table. For example, if $_cm->modname is 'quiz', this
 134      * will be a row from the quiz table.
 135      */
 136     protected $_module = null;
 137
 138     /**
 139      * @var context The context that this page belongs to.
 140      */
 141     protected $_context = null;
 142
 143     /**
 144      * @var array This holds any categories that $_course belongs to, starting with the
 145      * particular category it belongs to, and working out through any parent
 146      * categories to the top level. These are loaded progressively, if needed.
 147      * There are three states. $_categories = null initially when nothing is
 148      * loaded; $_categories = array($id => $cat, $parentid => null) when we have
 149      * loaded $_course->category, but not any parents; and a complete array once
 150      * everything is loaded.
 151      */
 152     protected $_categories = null;
 153
 154     /**
 155      * @var array An array of CSS classes that should be added to the body tag in HTML.
 156      */
 157     protected $_bodyclasses = array();
 158
 159     /**
 160      * @var string The title for the page. Used within the title tag in the HTML head.
 161      */
 162     protected $_title = '';
 163
 164     /**
 165      * @var string The string to use as the heading of the page. Shown near the top of the
 166      * page within most themes.
 167      */
 168     protected $_heading = '';
 169
 170     /**
 171      * @var string The pagetype is used to describe the page and defaults to a representation
 172      * of the physical path to the page e.g. my-index, mod-quiz-attempt
 173      */
 174     protected $_pagetype = null;
 175
 176     /**
 177      * @var string The pagelayout to use when displaying this page. The
 178      * pagelayout needs to have been defined by the theme in use, or one of its
 179      * parents. By default base is used however standard is the more common layout.
 180      * Note that this gets automatically set by core during operations like
 181      * require_login.
 182      */
 183     protected $_pagelayout = 'base';
 184
 185     /**
 186      * @var array List of theme layout options, these are ignored by core.
 187      * To be used in individual theme layout files only.
 188      */
 189     protected $_layout_options = null;
 190
 191     /**
 192      * @var string An optional arbitrary parameter that can be set on pages where the context
 193      * and pagetype is not enough to identify the page.
 194      */
 195     protected $_subpage = '';
 196
 197     /**
 198      * @var string Set a different path to use for the 'Moodle docs for this page' link.
 199      * By default, it uses the path of the file for instance mod/quiz/attempt.
 200      */
 201     protected $_docspath = null;
 202
 203     /**
 204      * @var string A legacy class that will be added to the body tag
 205      */
 206     protected $_legacyclass = null;
 207
 208     /**
 209      * @var moodle_url The URL for this page. This is mandatory and must be set
 210      * before output is started.
 211      */
 212     protected $_url = null;
 213
 214     /**
 215      * @var array An array of links to alternative versions of this page.
 216      * Primarily used for RSS versions of the current page.
 217      */
 218     protected $_alternateversions = array();
 219
 220     /**
 221      * @var block_manager The blocks manager for this page. It is reponsible for
 222      * the blocks and there content on this page.
 223      */
 224     protected $_blocks = null;
 225
 226     /**
 227      * @var page_requirements_manager Page requirements manager. It is reponsible
 228      * for all JavaScript and CSS resources required by this page.
 229      */
 230     protected $_requires = null;
 231
 232     /**
 233      * @var string The capability required by the user in order to edit blocks
 234      * and block settings on this page.
 235      */
 236     protected $_blockseditingcap = 'moodle/site:manageblocks';
 237
 238     /**
 239      * @var bool An internal flag to record when block actions have been processed.
 240      * Remember block actions occur on the current URL and it is important that
 241      * even they are never executed more than once.
 242      */
 243     protected $_block_actions_done = false;
 244
 245     /**
 246      * @var array An array of any other capabilities the current user must have
 247      * in order to editing the page and/or its content (not just blocks).
 248      */
 249     protected $_othereditingcaps = array();
 250
 251     /**
 252      * @var bool Sets whether this page should be cached by the browser or not.
 253      * If it is set to true (default) the page is served with caching headers.
 254      */
 255     protected $_cacheable = true;
 256
 257     /**
 258      * @var string Can be set to the ID of an element on the page, if done that
 259      * element receives focus when the page loads.
 260      */
 261     protected $_focuscontrol = '';
 262
 263     /**
 264      * @var string HTML to go where the turn on editing button is located. This
 265      * is nearly a legacy item and not used very often any more.
 266      */
 267     protected $_button = '';
 268
 269     /**
 270      * @var theme_config The theme to use with this page. This has to be properly
 271      * initialised via {@link moodle_page::initialise_theme_and_output()} which
 272      * happens magically before any operation that requires it.
 273      */
 274     protected $_theme = null;
 275
 276     /**
 277      * @var global_navigation Contains the global navigation structure.
 278      */
 279     protected $_navigation = null;
 280
 281     /**
 282      * @var settings_navigation Contains the settings navigation structure.
 283      */
 284     protected $_settingsnav = null;
 285
 286     /**
 287      * @var navbar Contains the navbar structure.
 288      */
 289     protected $_navbar = null;
 290
 291     /**
 292      * @var string The menu (or actions) to display in the heading.
 293      */
 294     protected $_headingmenu = null;
 295
 296     /**
 297      * @var array stack trace. Then the theme is initialised, we save the stack
 298      * trace, for use in error messages.
 299      */
 300     protected $_wherethemewasinitialised = null;
 301
 302     /**
 303      * @var xhtml_container_stack Tracks XHTML tags on this page that have been
 304      * opened but not closed.
 305      */
 306     protected $_opencontainers;
 307
 308     /**
 309      * @var int Sets the page to refresh after a given delay (in seconds) using
 310      * meta refresh in {@link standard_head_html()} in outputlib.php
 311      * If set to null(default) the page is not refreshed
 312      */
 313     protected $_periodicrefreshdelay = null;
 314
 315     /**
 316      * @var array Associative array of browser shortnames (as used by check_browser_version)
 317      * and their minimum required versions
 318      */
 319     protected $_legacybrowsers = array('MSIE' => 6.0);
 320
 321     /**
 322      * @var string Is set to the name of the device type in use.
 323      * This will we worked out when it is first used.
 324      */
 325     protected $_devicetypeinuse = null;
 326
 327     /**
 328      * @var bool Used to determine if HTTPS should be required for login.
 329      */
 330     protected $_https_login_required = false;
 331
 332     /**
 333      * @var bool Determines if popup notifications allowed on this page.
 334      * Code such as the quiz module disables popup notifications in situations
 335      * such as upgrading or completing a quiz.
 336      */
 337     protected $_popup_notification_allowed = true;
 338
 339     // Magic getter methods =============================================================
 340     // Due to the __get magic below, you normally do not call these as $PAGE->magic_get_x
 341     // methods, but instead use the $PAGE->x syntax.
 342
 343     /**
 344      * Please do not call this method directly, use the ->state syntax. {@link moodle_page::__get()}.
 345      * @return integer one of the STATE_XXX constants. You should not normally need
 346      * to use this in your code. It is intended for internal use by this class
 347      * and its friends like print_header, to check that everything is working as
 348      * expected. Also accessible as $PAGE->state.
 349      */
 350     protected function magic_get_state() {
 351         return $this->_state;
 352     }
 353
 354     /**
 355      * Please do not call this method directly, use the ->headerprinted syntax. {@link moodle_page::__get()}.
 356      * @return bool has the header already been printed?
 357      */
 358     protected function magic_get_headerprinted() {
 359         return $this->_state >= self::STATE_IN_BODY;
 360     }
 361
 362     /**
 363      * Please do not call this method directly, use the ->course syntax. {@link moodle_page::__get()}.
 364      * @return stdClass the current course that we are inside - a row from the
 365      * course table. (Also available as $COURSE global.) If we are not inside
 366      * an actual course, this will be the site course.
 367      */
 368     protected function magic_get_course() {
 369         global $SITE;
 370         if (is_null($this->_course)) {
 371             return $SITE;
 372         }
 373         return $this->_course;
 374     }
 375
 376     /**
 377      * Please do not call this method directly, use the ->cm syntax. {@link moodle_page::__get()}.
 378      * @return cm_info the course_module that this page belongs to. Will be null
 379      * if this page is not within a module. This is a full cm object, as loaded
 380      * by get_coursemodule_from_id or get_coursemodule_from_instance,
 381      * so the extra modname and name fields are present.
 382      */
 383     protected function magic_get_cm() {
 384         return $this->_cm;
 385     }
 386
 387     /**
 388      * Please do not call this method directly, use the ->activityrecord syntax. {@link moodle_page::__get()}.
 389      * @return stdClass the row from the activities own database table (for example
 390      * the forum or quiz table) that this page belongs to. Will be null
 391      * if this page is not within a module.
 392      */
 393     protected function magic_get_activityrecord() {
 394         if (is_null($this->_module) && !is_null($this->_cm)) {
 395             $this->load_activity_record();
 396         }
 397         return $this->_module;
 398     }
 399
 400     /**
 401      * Please do not call this method directly, use the ->activityname syntax. {@link moodle_page::__get()}.
 402      * @return string the The type of activity we are in, for example 'forum' or 'quiz'.
 403      * Will be null if this page is not within a module.
 404      */
 405     protected function magic_get_activityname() {
 406         if (is_null($this->_cm)) {
 407             return null;
 408         }
 409         return $this->_cm->modname;
 410     }
 411
 412     /**
 413      * Please do not call this method directly, use the ->category syntax. {@link moodle_page::__get()}.
 414      * @return stdClass the category that the page course belongs to. If there isn't one
 415      * (that is, if this is the front page course) returns null.
 416      */
 417     protected function magic_get_category() {
 418         $this->ensure_category_loaded();
 419         if (!empty($this->_categories)) {
 420             return reset($this->_categories);
 421         } else {
 422             return null;
 423         }
 424     }
 425
 426     /**
 427      * Please do not call this method directly, use the ->categories syntax. {@link moodle_page::__get()}.
 428      * @return array an array of all the categories the page course belongs to,
 429      * starting with the immediately containing category, and working out to
 430      * the top-level category. This may be the empty array if we are in the
 431      * front page course.
 432      */
 433     protected function magic_get_categories() {
 434         $this->ensure_categories_loaded();
 435         return $this->_categories;
 436     }
 437
 438     /**
 439      * Please do not call this method directly, use the ->context syntax. {@link moodle_page::__get()}.
 440      * @return context the main context to which this page belongs.
 441      */
 442     protected function magic_get_context() {
 443         if (is_null($this->_context)) {
 444             if (CLI_SCRIPT or NO_MOODLE_COOKIES) {
 445                 // cli scripts work in system context, do not annoy devs with debug info
 446                 // very few scripts do not use cookies, we can safely use system as default context there
 447             } else {
 448                 debugging('Coding problem: $PAGE->context was not set. You may have forgotten '
 449                     .'to call require_login() or $PAGE->set_context(). The page may not display '
 450                     .'correctly as a result');
 451             }
 452             $this->_context = context_system::instance();
 453         }
 454         return $this->_context;
 455     }
 456
 457     /**
 458      * Please do not call this method directly, use the ->pagetype syntax. {@link moodle_page::__get()}.
 459      * @return string e.g. 'my-index' or 'mod-quiz-attempt'.
 460      */
 461     protected function magic_get_pagetype() {
 462         global $CFG;
 463         if (is_null($this->_pagetype) || isset($CFG->pagepath)) {
 464             $this->initialise_default_pagetype();
 465         }
 466         return $this->_pagetype;
 467     }
 468
 469     /**
 470      * Please do not call this method directly, use the ->pagetype syntax. {@link moodle_page::__get()}.
 471      * @return string The id to use on the body tag, uses {@link magic_get_pagetype()}.
 472      */
 473     protected function magic_get_bodyid() {
 474         return 'page-'.$this->pagetype;
 475     }
 476
 477     /**
 478      * Please do not call this method directly, use the ->pagelayout syntax. {@link moodle_page::__get()}.
 479      * @return string the general type of page this is. For example 'standard', 'popup', 'home'.
 480      *      Allows the theme to display things differently, if it wishes to.
 481      */
 482     protected function magic_get_pagelayout() {
 483         return $this->_pagelayout;
 484     }
 485
 486     /**
 487      * Please do not call this method directly, use the ->layout_options syntax. {@link moodle_page::__get()}.
 488      * @return array returns arrays with options for layout file
 489      */
 490     protected function magic_get_layout_options() {
 491         if (!is_array($this->_layout_options)) {
 492             $this->_layout_options = $this->_theme->pagelayout_options($this->pagelayout);
 493         }
 494         return $this->_layout_options;
 495     }
 496
 497     /**
 498      * Please do not call this method directly, use the ->subpage syntax. {@link moodle_page::__get()}.
 499      * @return string The subpage identifier, if any.
 500      */
 501     protected function magic_get_subpage() {
 502         return $this->_subpage;
 503     }
 504
 505     /**
 506      * Please do not call this method directly, use the ->bodyclasses syntax. {@link moodle_page::__get()}.
 507      * @return string the class names to put on the body element in the HTML.
 508      */
 509     protected function magic_get_bodyclasses() {
 510         return implode(' ', array_keys($this->_bodyclasses));
 511     }
 512
 513     /**
 514      * Please do not call this method directly, use the ->title syntax. {@link moodle_page::__get()}.
 515      * @return string the title that should go in the <head> section of the HTML of this page.
 516      */
 517     protected function magic_get_title() {
 518         return $this->_title;
 519     }
 520
 521     /**
 522      * Please do not call this method directly, use the ->heading syntax. {@link moodle_page::__get()}.
 523      * @return string the main heading that should be displayed at the top of the <body>.
 524      */
 525     protected function magic_get_heading() {
 526         return $this->_heading;
 527     }
 528
 529     /**
 530      * Please do not call this method directly, use the ->heading syntax. {@link moodle_page::__get()}.
 531      * @return string The menu (or actions) to display in the heading
 532      */
 533     protected function magic_get_headingmenu() {
 534         return $this->_headingmenu;
 535     }
 536
 537     /**
 538      * Please do not call this method directly, use the ->docspath syntax. {@link moodle_page::__get()}.
 539      * @return string the path to the Moodle docs for this page.
 540      */
 541     protected function magic_get_docspath() {
 542         if (is_string($this->_docspath)) {
 543             return $this->_docspath;
 544         } else {
 545             return str_replace('-', '/', $this->pagetype);
 546         }
 547     }
 548
 549     /**
 550      * Please do not call this method directly, use the ->url syntax. {@link moodle_page::__get()}.
 551      * @return moodle_url the clean URL required to load the current page. (You
 552      * should normally use this in preference to $ME or $FULLME.)
 553      */
 554     protected function magic_get_url() {
 555         global $FULLME;
 556         if (is_null($this->_url)) {
 557             debugging('This page did not call $PAGE->set_url(...). Using '.s($FULLME), DEBUG_DEVELOPER);
 558             $this->_url = new moodle_url($FULLME);
 559             // Make sure the guessed URL cannot lead to dangerous redirects.
 560             $this->_url->remove_params('sesskey');
 561         }
 562         return new moodle_url($this->_url); // Return a clone for safety.
 563     }
 564
 565     /**
 566      * The list of alternate versions of this page.
 567      * @return array mime type => object with ->url and ->title.
 568      */
 569     protected function magic_get_alternateversions() {
 570         return $this->_alternateversions;
 571     }
 572
 573     /**
 574      * Please do not call this method directly, use the ->blocks syntax. {@link moodle_page::__get()}.
 575      * @return blocks_manager the blocks manager object for this page.
 576      */
 577     protected function magic_get_blocks() {
 578         global $CFG;
 579         if (is_null($this->_blocks)) {
 580             if (!empty($CFG->blockmanagerclass)) {
 581                 if (!empty($CFG->blockmanagerclassfile)) {
 582                     require_once($CFG->blockmanagerclassfile);
 583                 }
 584                 $classname = $CFG->blockmanagerclass;
 585             } else {
 586                 $classname = 'block_manager';
 587             }
 588             $this->_blocks = new $classname($this);
 589         }
 590         return $this->_blocks;
 591     }
 592
 593     /**
 594      * Please do not call this method directly, use the ->requires syntax. {@link moodle_page::__get()}.
 595      * @return page_requirements_manager tracks the JavaScript, CSS files, etc. required by this page.
 596      */
 597     protected function magic_get_requires() {
 598         global $CFG;
 599         if (is_null($this->_requires)) {
 600             $this->_requires = new page_requirements_manager();
 601         }
 602         return $this->_requires;
 603     }
 604
 605     /**
 606      * Please do not call this method directly, use the ->cacheable syntax. {@link moodle_page::__get()}.
 607      * @return bool can this page be cached by the user's browser.
 608      */
 609     protected function magic_get_cacheable() {
 610         return $this->_cacheable;
 611     }
 612
 613     /**
 614      * Please do not call this method directly, use the ->focuscontrol syntax. {@link moodle_page::__get()}.
 615      * @return string the id of the HTML element to be focused when the page has loaded.
 616      */
 617     protected function magic_get_focuscontrol() {
 618         return $this->_focuscontrol;
 619     }
 620
 621     /**
 622      * Please do not call this method directly, use the ->button syntax. {@link moodle_page::__get()}.
 623      * @return string the HTML to go where the Turn editing on button normally goes.
 624      */
 625     protected function magic_get_button() {
 626         return $this->_button;
 627     }
 628
 629     /**
 630      * Please do not call this method directly, use the ->theme syntax. {@link moodle_page::__get()}.
 631      * @return theme_config the initialised theme for this page.
 632      */
 633     protected function magic_get_theme() {
 634         if (is_null($this->_theme)) {
 635             $this->initialise_theme_and_output();
 636         }
 637         return $this->_theme;
 638     }
 639
 640     /**
 641      * Please do not call this method directly, use the ->devicetypeinuse syntax. {@link moodle_page::__get()}.
 642      * @return string The device type being used.
 643      */
 644     protected function magic_get_devicetypeinuse() {
 645         if (empty($this->_devicetypeinuse)) {
 646             $this->_devicetypeinuse = get_user_device_type();
 647         }
 648         return $this->_devicetypeinuse;
 649     }
 650
 651     /**
 652      * Please do not call this method directly use the ->periodicrefreshdelay syntax
 653      * {@link moodle_page::__get()}
 654      * @return int The periodic refresh delay to use with meta refresh
 655      */
 656     protected function magic_get_periodicrefreshdelay() {
 657         return $this->_periodicrefreshdelay;
 658     }
 659
 660     /**
 661      * Please do not call this method directly use the ->opencontainers syntax. {@link moodle_page::__get()}
 662      * @return xhtml_container_stack tracks XHTML tags on this page that have been opened but not closed.
 663      *      mainly for internal use by the rendering code.
 664      */
 665     protected function magic_get_opencontainers() {
 666         if (is_null($this->_opencontainers)) {
 667             $this->_opencontainers = new xhtml_container_stack();
 668         }
 669         return $this->_opencontainers;
 670     }
 671
 672     /**
 673      * Return the navigation object
 674      * @return global_navigation
 675      */
 676     protected function magic_get_navigation() {
 677         if ($this->_navigation === null) {
 678             $this->_navigation = new global_navigation($this);
 679         }
 680         return $this->_navigation;
 681     }
 682
 683     /**
 684      * Return a navbar object
 685      * @return navbar
 686      */
 687     protected function magic_get_navbar() {
 688         if ($this->_navbar === null) {
 689             $this->_navbar = new navbar($this);
 690         }
 691         return $this->_navbar;
 692     }
 693
 694     /**
 695      * Returns the settings navigation object
 696      * @return settings_navigation
 697      */
 698     protected function magic_get_settingsnav() {
 699         if ($this->_settingsnav === null) {
 700             $this->_settingsnav = new settings_navigation($this);
 701             $this->_settingsnav->initialise();
 702         }
 703         return $this->_settingsnav;
 704     }
 705
 706     /**
 707      * PHP overloading magic to make the $PAGE->course syntax work by redirecting
 708      * it to the corresponding $PAGE->magic_get_course() method if there is one, and
 709      * throwing an exception if not.
 710      *
 711      * @param string $name property name
 712      * @return mixed
 713      */
 714     public function __get($name) {
 715         $getmethod = 'magic_get_' . $name;
 716         if (method_exists($this, $getmethod)) {
 717             return $this->$getmethod();
 718         } else {
 719             throw new coding_exception('Unknown property ' . $name . ' of $PAGE.');
 720         }
 721     }
 722
 723     /**
 724      * PHP overloading magic to catch obvious coding errors.
 725      *
 726      * This method has been created to catch obvious coding errors where the
 727      * developer has tried to set a page property using $PAGE->key = $value.
 728      * In the moodle_page class all properties must be set using the appropriate
 729      * $PAGE->set_something($value) method.
 730      *
 731      * @param string $name property name
 732      * @param mixed $value Value
 733      * @return void Throws exception if field not defined in page class
 734      */
 735     public function __set($name, $value) {
 736         if (method_exists($this, 'set_' . $name)) {
 737             throw new coding_exception('Invalid attempt to modify page object', "Use \$PAGE->set_$name() instead.");
 738         } else {
 739             throw new coding_exception('Invalid attempt to modify page object', "Unknown property $name");
 740         }
 741     }
 742
 743     // Other information getting methods ==========================================
 744
 745     /**
 746      * Returns instance of page renderer
 747      *
 748      * @param string $component name such as 'core', 'mod_forum' or 'qtype_multichoice'.
 749      * @param string $subtype optional subtype such as 'news' resulting to 'mod_forum_news'
 750      * @param string $target one of rendering target constants
 751      * @return renderer_base
 752      */
 753     public function get_renderer($component, $subtype = null, $target = null) {
 754         return $this->magic_get_theme()->get_renderer($this, $component, $subtype, $target);
 755     }
 756
 757     /**
 758      * Checks to see if there are any items on the navbar object
 759      *
 760      * @return bool true if there are, false if not
 761      */
 762     public function has_navbar() {
 763         if ($this->_navbar === null) {
 764             $this->_navbar = new navbar($this);
 765         }
 766         return $this->_navbar->has_items();
 767     }
 768
 769     /**
 770      * Should the current user see this page in editing mode.
 771      * That is, are they allowed to edit this page, and are they currently in
 772      * editing mode.
 773      * @return bool
 774      */
 775     public function user_is_editing() {
 776         global $USER;
 777         return !empty($USER->editing) && $this->user_allowed_editing();
 778     }
 779
 780     /**
 781      * Does the user have permission to edit blocks on this page.
 782      * @return bool
 783      */
 784     public function user_can_edit_blocks() {
 785         return has_capability($this->_blockseditingcap, $this->_context);
 786     }
 787
 788     /**
 789      * Does the user have permission to see this page in editing mode.
 790      * @return bool
 791      */
 792     public function user_allowed_editing() {
 793         return has_any_capability($this->all_editing_caps(), $this->_context);
 794     }
 795
 796     /**
 797      * Get a description of this page. Normally displayed in the footer in
 798      * developer debug mode.
 799      * @return string
 800      */
 801     public function debug_summary() {
 802         $summary = '';
 803         $summary .= 'General type: ' . $this->pagelayout . '. ';
 804         if (!during_initial_install()) {
 805             $summary .= 'Context ' . print_context_name($this->_context) . ' (context id ' . $this->_context->id . '). ';
 806         }
 807         $summary .= 'Page type ' . $this->pagetype .  '. ';
 808         if ($this->subpage) {
 809             'Sub-page ' . $this->subpage .  '. ';
 810         }
 811         return $summary;
 812     }
 813
 814     // Setter methods =============================================================
 815
 816     /**
 817      * Set the state. The state must be one of that STATE_... constants, and
 818      * the state is only allowed to advance one step at a time.
 819      *
 820      * @param integer $state The new state.
 821      */
 822     public function set_state($state) {
 823         if ($state != $this->_state + 1 || $state > self::STATE_DONE) {
 824             throw new coding_exception('Invalid state passed to moodle_page::set_state. We are in state ' .
 825                     $this->_state . ' and state ' . $state . ' was requested.');
 826         }
 827
 828         if ($state == self::STATE_PRINTING_HEADER) {
 829             $this->starting_output();
 830         }
 831
 832         $this->_state = $state;
 833     }
 834
 835     /**
 836      * Set the current course. This sets both $PAGE->course and $COURSE. It also
 837      * sets the right theme and locale.
 838      *
 839      * Normally you don't need to call this function yourself, require_login will
 840      * call it for you if you pass a $course to it. You can use this function
 841      * on pages that do need to call require_login().
 842      *
 843      * Sets $PAGE->context to the course context, if it is not already set.
 844      *
 845      * @param stdClass $course the course to set as the global course.
 846      */
 847     public function set_course($course) {
 848         global $COURSE, $PAGE, $CFG, $SITE;
 849
 850         if (empty($course->id)) {
 851             throw new coding_exception('$course passed to moodle_page::set_course does not look like a proper course object.');
 852         }
 853
 854         $this->ensure_theme_not_set();
 855
 856         if (!empty($this->_course->id) && $this->_course->id != $course->id) {
 857             $this->_categories = null;
 858         }
 859
 860         $this->_course = clone($course);
 861
 862         if ($this === $PAGE) {
 863             $COURSE = $this->_course;
 864             moodle_setlocale();
 865         }
 866
 867         if (!$this->_context) {
 868             $this->set_context(context_course::instance($this->_course->id));
 869         }
 870
 871         // notify course format that this page is set for the course
 872         if ($this->_course->id != $SITE->id) {
 873             require_once($CFG->dirroot.'/course/lib.php');
 874             $courseformat = course_get_format($this->_course);
 875             $this->add_body_class('format-'. $courseformat->get_format());
 876             $courseformat->page_set_course($this);
 877         } else {
 878             $this->add_body_class('format-site');
 879         }
 880     }
 881
 882     /**
 883      * Set the main context to which this page belongs.
 884      *
 885      * @param context $context a context object, normally obtained with get_context_instance.
 886      */
 887     public function set_context($context) {
 888         if ($context === null) {
 889             // extremely ugly hack which sets context to some value in order to prevent warnings,
 890             // use only for core error handling!!!!
 891             if (!$this->_context) {
 892                 $this->_context = context_system::instance();
 893             }
 894             return;
 895         }
 896
 897         // ideally we should set context only once
 898         if (isset($this->_context)) {
 899             if ($context->id == $this->_context->id) {
 900                 // fine - no change needed
 901             } else if ($this->_context->contextlevel == CONTEXT_SYSTEM or $this->_context->contextlevel == CONTEXT_COURSE) {
 902                 // hmm - not ideal, but it might produce too many warnings due to the design of require_login
 903             } else if ($this->_context->contextlevel == CONTEXT_MODULE and $this->_context->id == get_parent_contextid($context)) {
 904                 // hmm - most probably somebody did require_login() and after that set the block context
 905             } else {
 906                 // we do not want devs to do weird switching of context levels on the fly,
 907                 // because we might have used the context already such as in text filter in page title
 908                 debugging('Coding problem: unsupported modification of PAGE->context from '.$this->_context->contextlevel.' to '.$context->contextlevel);
 909             }
 910         }
 911
 912         $this->_context = $context;
 913     }
 914
 915     /**
 916      * The course module that this page belongs to (if it does belong to one).
 917      *
 918      * @param stdClass|cm_info $cm a record from course_modules table or cm_info from get_fast_modinfo().
 919      * @param stdClass $course
 920      * @param stdClass $module
 921      * @return void
 922      */
 923     public function set_cm($cm, $course = null, $module = null) {
 924         global $DB, $CFG, $SITE;
 925
 926         if (!isset($cm->id) || !isset($cm->course)) {
 927             throw new coding_exception('Invalid $cm parameter for $PAGE object, it has to be instance of cm_info or record from the course_modules table.');
 928         }
 929
 930         if (!$this->_course || $this->_course->id != $cm->course) {
 931             if (!$course) {
 932                 $course = $DB->get_record('course', array('id' => $cm->course), '*', MUST_EXIST);
 933             }
 934             if ($course->id != $cm->course) {
 935                 throw new coding_exception('The course you passed to $PAGE->set_cm does not correspond to the $cm.');
 936             }
 937             $this->set_course($course);
 938         }
 939
 940         // make sure we have a $cm from get_fast_modinfo as this contains activity access details
 941         if (!($cm instanceof cm_info)) {
 942             $modinfo = get_fast_modinfo($this->_course);
 943             $cm = $modinfo->get_cm($cm->id);
 944         }
 945         $this->_cm = $cm;
 946
 947         // unfortunately the context setting is a mess, let's try to work around some common block problems and show some debug messages
 948         if (empty($this->_context) or $this->_context->contextlevel != CONTEXT_BLOCK) {
 949             $context = context_module::instance($cm->id);
 950             $this->set_context($context);
 951         }
 952
 953         if ($module) {
 954             $this->set_activity_record($module);
 955         }
 956
 957         // notify course format that this page is set for the course module
 958         if ($this->_course->id != $SITE->id) {
 959             require_once($CFG->dirroot.'/course/lib.php');
 960             course_get_format($this->_course)->page_set_cm($this);
 961         }
 962     }
 963
 964     /**
 965      * Sets the activity record. This could be a row from the main table for a
 966      * module. For instance if the current module (cm) is a forum this should be a row
 967      * from the forum table.
 968      *
 969      * @param stdClass $module A row from the main database table for the module that this
 970      * page belongs to.
 971      * @return void
 972      */
 973     public function set_activity_record($module) {
 974         if (is_null($this->_cm)) {
 975             throw new coding_exception('You cannot call $PAGE->set_activity_record until after $PAGE->cm has been set.');
 976         }
 977         if ($module->id != $this->_cm->instance || $module->course != $this->_course->id) {
 978             throw new coding_exception('The activity record your are trying to set does not seem to correspond to the cm that has been set.');
 979         }
 980         $this->_module = $module;
 981     }
 982
 983     /**
 984      * Sets the pagetype to use for this page.
 985      *
 986      * Normally you do not need to set this manually, it is automatically created
 987      * from the script name. However, on some pages this is overridden.
 988      * For example the page type for course/view.php includes the course format,
 989      * for example 'course-view-weeks'. This gets used as the id attribute on
 990      * <body> and also for determining which blocks are displayed.
 991      *
 992      * @param string $pagetype e.g. 'my-index' or 'mod-quiz-attempt'.
 993      */
 994     public function set_pagetype($pagetype) {
 995         $this->_pagetype = $pagetype;
 996     }
 997
 998     /**
 999      * Sets the layout to use for this page.
1000      *
1001      * The page layout determines how the page will be displayed, things such as
1002      * block regions, content areas, etc are controlled by the layout.
1003      * The theme in use for the page will determine that the layout contains.
1004      *
1005      * This properly defaults to 'base', so you only need to call this function if
1006      * you want something different. The exact range of supported layouts is specified
1007      * in the standard theme.
1008      *
1009      * For an idea of the common page layouts see
1010      * {@link http://docs.moodle.org/dev/Themes_2.0#The_different_layouts_as_of_August_17th.2C_2010}
1011      * But please keep in mind that it may be (and normally is) out of date.
1012      * The only place to find an accurate up-to-date list of the page layouts
1013      * available for your version of Moodle is {@link theme/base/config.php}
1014      *
1015      * @param string $pagelayout the page layout this is. For example 'popup', 'home'.
1016      */
1017     public function set_pagelayout($pagelayout) {
1018         /**
1019          * Uncomment this to debug theme pagelayout issues like missing blocks.
1020          *
1021          * if (!empty($this->_wherethemewasinitialised) && $pagelayout != $this->_pagelayout) {
1022          *     debugging('Page layout has already been set and cannot be changed.', DEBUG_DEVELOPER);
1023          * }
1024          */
1025         $this->_pagelayout = $pagelayout;
1026     }
1027
1028     /**
1029      * If context->id and pagetype are not enough to uniquely identify this page,
1030      * then you can set a subpage id as well. For example, the tags page sets
1031      *
1032      * @param string $subpage an arbitrary identifier that, along with context->id
1033      *      and pagetype, uniquely identifies this page.
1034      */
1035     public function set_subpage($subpage) {
1036         if (empty($subpage)) {
1037             $this->_subpage = '';
1038         } else {
1039             $this->_subpage = $subpage;
1040         }
1041     }
1042
1043     /**
1044      * Adds a CSS class to the body tag of the page.
1045      *
1046      * @param string $class add this class name ot the class attribute on the body tag.
1047      */
1048     public function add_body_class($class) {
1049         if ($this->_state > self::STATE_BEFORE_HEADER) {
1050             throw new coding_exception('Cannot call moodle_page::add_body_class after output has been started.');
1051         }
1052         $this->_bodyclasses[$class] = 1;
1053     }
1054
1055     /**
1056      * Adds an array of body classes to the body tag of this page.
1057      *
1058      * @param array $classes this utility method calls add_body_class for each array element.
1059      */
1060     public function add_body_classes($classes) {
1061         foreach ($classes as $class) {
1062             $this->add_body_class($class);
1063         }
1064     }
1065
1066     /**
1067      * Sets the title for the page.
1068      * This is normally used within the title tag in the head of the page.
1069      *
1070      * @param string $title the title that should go in the <head> section of the HTML of this page.
1071      */
1072     public function set_title($title) {
1073         $title = format_string($title);
1074         $title = strip_tags($title);
1075         $title = str_replace('"', '&quot;', $title);
1076         $this->_title = $title;
1077     }
1078
1079     /**
1080      * Sets the heading to use for the page.
1081      * This is normally used as the main heading at the top of the content.
1082      *
1083      * @param string $heading the main heading that should be displayed at the top of the <body>.
1084      */
1085     public function set_heading($heading) {
1086         $this->_heading = format_string($heading);
1087     }
1088
1089     /**
1090      * Sets some HTML to use next to the heading {@link moodle_page::set_heading()}
1091      *
1092      * @param string $menu The menu/content to show in the heading
1093      */
1094     public function set_headingmenu($menu) {
1095         $this->_headingmenu = $menu;
1096     }
1097
1098     /**
1099      * Set the course category this page belongs to manually.
1100      *
1101      * This automatically sets $PAGE->course to be the site course. You cannot
1102      * use this method if you have already set $PAGE->course - in that case,
1103      * the category must be the one that the course belongs to. This also
1104      * automatically sets the page context to the category context.
1105      *
1106      * @param integer $categoryid The id of the category to set.
1107      */
1108     public function set_category_by_id($categoryid) {
1109         global $SITE, $DB;
1110         if (!is_null($this->_course)) {
1111             throw new coding_exception('Attempt to manually set the course category when the course has been set. This is not allowed.');
1112         }
1113         if (is_array($this->_categories)) {
1114             throw new coding_exception('Course category has already been set. You are not allowed to change it.');
1115         }
1116         $this->ensure_theme_not_set();
1117         $this->set_course($SITE);
1118         $this->load_category($categoryid);
1119         $this->set_context(context_coursecat::instance($categoryid));
1120     }
1121
1122     /**
1123      * Set a different path to use for the 'Moodle docs for this page' link.
1124      *
1125      * By default, it uses the pagetype, which is normally the same as the
1126      * script name. So, for example, for mod/quiz/attempt.php, pagetype is
1127      * mod-quiz-attempt, and so docspath is mod/quiz/attempt.
1128      *
1129      * @param string $path the path to use at the end of the moodle docs URL.
1130      */
1131     public function set_docs_path($path) {
1132         $this->_docspath = $path;
1133     }
1134
1135     /**
1136      * You should call this method from every page to set the cleaned-up URL
1137      * that should be used to return to this page.
1138      *
1139      * Used, for example, by the blocks editing UI to know where to return the
1140      * user after an action.
1141      * For example, course/view.php does:
1142      *      $id = optional_param('id', 0, PARAM_INT);
1143      *      $PAGE->set_url('/course/view.php', array('id' => $id));
1144      *
1145      * @param moodle_url|string $url URL relative to $CFG->wwwroot or {@link moodle_url} instance
1146      * @param array $params parameters to add to the URL
1147      */
1148     public function set_url($url, array $params = null) {
1149         global $CFG;
1150
1151         if (is_string($url)) {
1152             if (strpos($url, 'http') === 0) {
1153                 // ok
1154             } else if (strpos($url, '/') === 0) {
1155                 // we have to use httpswwwroot here, because of loginhttps pages
1156                 $url = $CFG->httpswwwroot . $url;
1157             } else {
1158                 throw new coding_exception('Invalid parameter $url, has to be full url or in shortened form starting with /.');
1159             }
1160         }
1161
1162         $this->_url = new moodle_url($url, $params);
1163
1164         $fullurl = $this->_url->out_omit_querystring();
1165         if (strpos($fullurl, "$CFG->httpswwwroot/") !== 0) {
1166             debugging('Most probably incorrect set_page() url argument, it does not match the httpswwwroot!');
1167         }
1168         $shorturl = str_replace("$CFG->httpswwwroot/", '', $fullurl);
1169
1170         if (is_null($this->_pagetype)) {
1171             $this->initialise_default_pagetype($shorturl);
1172         }
1173     }
1174
1175     /**
1176      * Make sure page URL does not contain the given URL parameter.
1177      *
1178      * This should not be necessary if the script has called set_url properly.
1179      * However, in some situations like the block editing actions; when the URL
1180      * has been guessed, it will contain dangerous block-related actions.
1181      * Therefore, the blocks code calls this function to clean up such parameters
1182      * before doing any redirect.
1183      *
1184      * @param string $param the name of the parameter to make sure is not in the
1185      * page URL.
1186      */
1187     public function ensure_param_not_in_url($param) {
1188         $discard = $this->url; // Make sure $this->url is lazy-loaded;
1189         $this->_url->remove_params($param);
1190     }
1191
1192     /**
1193      * There can be alternate versions of some pages (for example an RSS feed version).
1194      * If such other version exist, call this method, and a link to the alternate
1195      * version will be included in the <head> of the page.
1196      *
1197      * @param string $title The title to give the alternate version.
1198      * @param string|moodle_url $url The URL of the alternate version.
1199      * @param string $mimetype The mime-type of the alternate version.
1200      */
1201     public function add_alternate_version($title, $url, $mimetype) {
1202         if ($this->_state > self::STATE_BEFORE_HEADER) {
1203             throw new coding_exception('Cannot call moodle_page::add_alternate_version after output has been started.');
1204         }
1205         $alt = new stdClass;
1206         $alt->title = $title;
1207         $alt->url = $url;
1208         $this->_alternateversions[$mimetype] = $alt;
1209     }
1210
1211     /**
1212      * Specify a form control should be focused when the page has loaded.
1213      *
1214      * @param string $controlid the id of the HTML element to be focused.
1215      */
1216     public function set_focuscontrol($controlid) {
1217         $this->_focuscontrol = $controlid;
1218     }
1219
1220     /**
1221      * Specify a fragment of HTML that goes where the 'Turn editing on' button normally goes.
1222      *
1223      * @param string $html the HTML to display there.
1224      */
1225     public function set_button($html) {
1226         $this->_button = $html;
1227     }
1228
1229     /**
1230      * Set the capability that allows users to edit blocks on this page.
1231      *
1232      * Normally the default of 'moodle/site:manageblocks' is used, but a few
1233      * pages like the My Moodle page need to use a different capability
1234      * like 'moodle/my:manageblocks'.
1235      *
1236      * @param string $capability a capability.
1237      */
1238     public function set_blocks_editing_capability($capability) {
1239         $this->_blockseditingcap = $capability;
1240     }
1241
1242     /**
1243      * Some pages let you turn editing on for reasons other than editing blocks.
1244      * If that is the case, you can pass other capabilities that let the user
1245      * edit this page here.
1246      *
1247      * @param string|array $capability either a capability, or an array of capabilities.
1248      */
1249     public function set_other_editing_capability($capability) {
1250         if (is_array($capability)) {
1251             $this->_othereditingcaps = array_unique($this->_othereditingcaps + $capability);
1252         } else {
1253             $this->_othereditingcaps[] = $capability;
1254         }
1255     }
1256
1257     /**
1258      * Sets whether the browser should cache this page or not.
1259      *
1260      * @return bool $cacheable can this page be cached by the user's browser.
1261      */
1262     public function set_cacheable($cacheable) {
1263         $this->_cacheable = $cacheable;
1264     }
1265
1266     /**
1267      * Sets the page to periodically refresh
1268      *
1269      * This function must be called before $OUTPUT->header has been called or
1270      * a coding exception will be thrown.
1271      *
1272      * @param int $delay Sets the delay before refreshing the page, if set to null
1273      *     refresh is cancelled
1274      */
1275     public function set_periodic_refresh_delay($delay=null) {
1276         if ($this->_state > self::STATE_BEFORE_HEADER) {
1277             throw new coding_exception('You cannot set a periodic refresh delay after the header has been printed');
1278         }
1279         if ($delay===null) {
1280             $this->_periodicrefreshdelay = null;
1281         } else if (is_int($delay)) {
1282             $this->_periodicrefreshdelay = $delay;
1283         }
1284     }
1285
1286     /**
1287      * Force this page to use a particular theme.
1288      *
1289      * Please use this cautiously.
1290      * It is only intended to be used by the themes selector admin page.
1291      *
1292      * @param string $themename the name of the theme to use.
1293      */
1294     public function force_theme($themename) {
1295         $this->ensure_theme_not_set();
1296         $this->_theme = theme_config::load($themename);
1297     }
1298
1299     /**
1300      * This function indicates that current page requires the https
1301      * when $CFG->loginhttps enabled.
1302      *
1303      * By using this function properly, we can ensure 100% https-ized pages
1304      * at our entire discretion (login, forgot_password, change_password)
1305      * @return void
1306      */
1307     public function https_required() {
1308         global $CFG;
1309
1310         if (!is_null($this->_url)) {
1311             throw new coding_exception('https_required() must be used before setting page url!');
1312         }
1313
1314         $this->ensure_theme_not_set();
1315
1316         $this->_https_login_required = true;
1317
1318         if (!empty($CFG->loginhttps)) {
1319             $CFG->httpswwwroot = str_replace('http:', 'https:', $CFG->wwwroot);
1320         } else {
1321             $CFG->httpswwwroot = $CFG->wwwroot;
1322         }
1323     }
1324
1325     /**
1326      * Makes sure that page previously marked with https_required()
1327      * is really using https://, if not it redirects to https://
1328      *
1329      * @return void (may redirect to https://self)
1330      */
1331     public function verify_https_required() {
1332         global $CFG, $FULLME;
1333
1334         if (is_null($this->_url)) {
1335             throw new coding_exception('verify_https_required() must be called after setting page url!');
1336         }
1337
1338         if (!$this->_https_login_required) {
1339             throw new coding_exception('verify_https_required() must be called only after https_required()!');
1340         }
1341
1342         if (empty($CFG->loginhttps)) {
1343             // https not required, so stop checking
1344             return;
1345         }
1346
1347         if (strpos($this->_url, 'https://')) {
1348             // detect if incorrect PAGE->set_url() used, it is recommended to use root-relative paths there
1349             throw new coding_exception('Invalid page url specified, it must start with https:// for pages that set https_required()!');
1350         }
1351
1352         if (!empty($CFG->sslproxy)) {
1353             // it does not make much sense to use sslproxy and loginhttps at the same time
1354             return;
1355         }
1356
1357         // now the real test and redirect!
1358         // NOTE: do NOT use this test for detection of https on current page because this code is not compatible with SSL proxies,
1359         //       instead use strpos($CFG->httpswwwroot, 'https:') === 0
1360         if (strpos($FULLME, 'https:') !== 0) {
1361             // this may lead to infinite redirect on misconfigured sites, in that case use $CFG->loginhttps=0; in /config.php
1362             redirect($this->_url);
1363         }
1364     }
1365
1366     // Initialisation methods =====================================================
1367     // These set various things up in a default way.
1368
1369     /**
1370      * This method is called when the page first moves out of the STATE_BEFORE_HEADER
1371      * state. This is our last change to initialise things.
1372      */
1373     protected function starting_output() {
1374         global $CFG;
1375
1376         if (!during_initial_install()) {
1377             $this->blocks->load_blocks();
1378             if (empty($this->_block_actions_done)) {
1379                 $this->_block_actions_done = true;
1380                 if ($this->blocks->process_url_actions($this)) {
1381                     redirect($this->url->out(false));
1382                 }
1383             }
1384             $this->blocks->create_all_block_instances();
1385         }
1386
1387         // If maintenance mode is on, change the page header.
1388         if (!empty($CFG->maintenance_enabled)) {
1389             $this->set_button('<a href="' . $CFG->wwwroot . '/' . $CFG->admin .
1390                     '/settings.php?section=maintenancemode">' . get_string('maintenancemode', 'admin') .
1391                     '</a> ' . $this->button);
1392
1393             $title = $this->title;
1394             if ($title) {
1395                 $title .= ' - ';
1396             }
1397             $this->set_title($title . get_string('maintenancemode', 'admin'));
1398         } else {
1399             // Show the messaging popup if there are messages
1400             message_popup_window();
1401         }
1402
1403         $this->initialise_standard_body_classes();
1404     }
1405
1406     /**
1407      * Method for use by Moodle core to set up the theme. Do not
1408      * use this in your own code.
1409      *
1410      * Make sure the right theme for this page is loaded. Tell our
1411      * blocks_manager about the theme block regions, and then, if
1412      * we are $PAGE, set up the global $OUTPUT.
1413      *
1414      * @return void
1415      */
1416     public function initialise_theme_and_output() {
1417         global $OUTPUT, $PAGE, $SITE;
1418
1419         if (!empty($this->_wherethemewasinitialised)) {
1420             return;
1421         }
1422
1423         if (!during_initial_install()) {
1424             // detect PAGE->context mess
1425             $this->magic_get_context();
1426         }
1427
1428         if (!$this->_course && !during_initial_install()) {
1429             $this->set_course($SITE);
1430         }
1431
1432         if (is_null($this->_theme)) {
1433             $themename = $this->resolve_theme();
1434             $this->_theme = theme_config::load($themename);
1435         }
1436
1437         $this->_theme->setup_blocks($this->pagelayout, $this->blocks);
1438
1439         if ($this === $PAGE) {
1440             $OUTPUT = $this->get_renderer('core');
1441         }
1442
1443         $this->_wherethemewasinitialised = debug_backtrace();
1444     }
1445
1446     /**
1447      * Work out the theme this page should use.
1448      *
1449      * This depends on numerous $CFG settings, and the properties of this page.
1450      *
1451      * @return string the name of the theme that should be used on this page.
1452      */
1453     protected function resolve_theme() {
1454         global $CFG, $USER, $SESSION;
1455
1456         if (empty($CFG->themeorder)) {
1457             $themeorder = array('course', 'category', 'session', 'user', 'site');
1458         } else {
1459             $themeorder = $CFG->themeorder;
1460             // Just in case, make sure we always use the site theme if nothing else matched.
1461             $themeorder[] = 'site';
1462         }
1463
1464         $mnetpeertheme = '';
1465         if (isloggedin() and isset($CFG->mnet_localhost_id) and $USER->mnethostid != $CFG->mnet_localhost_id) {
1466             require_once($CFG->dirroot.'/mnet/peer.php');
1467             $mnetpeer = new mnet_peer();
1468             $mnetpeer->set_id($USER->mnethostid);
1469             if ($mnetpeer->force_theme == 1 && $mnetpeer->theme != '') {
1470                 $mnetpeertheme = $mnetpeer->theme;
1471             }
1472         }
1473
1474         foreach ($themeorder as $themetype) {
1475             switch ($themetype) {
1476                 case 'course':
1477                     if (!empty($CFG->allowcoursethemes) && !empty($this->_course->theme) && $this->devicetypeinuse == 'default') {
1478                         return $this->_course->theme;
1479                     }
1480                 break;
1481
1482                 case 'category':
1483                     if (!empty($CFG->allowcategorythemes) && $this->devicetypeinuse == 'default') {
1484                         $categories = $this->categories;
1485                         foreach ($categories as $category) {
1486                             if (!empty($category->theme)) {
1487                                 return $category->theme;
1488                             }
1489                         }
1490                     }
1491                 break;
1492
1493                 case 'session':
1494                     if (!empty($SESSION->theme)) {
1495                         return $SESSION->theme;
1496                     }
1497                 break;
1498
1499                 case 'user':
1500                     if (!empty($CFG->allowuserthemes) && !empty($USER->theme) && $this->devicetypeinuse == 'default') {
1501                         if ($mnetpeertheme) {
1502                             return $mnetpeertheme;
1503                         } else {
1504                             return $USER->theme;
1505                         }
1506                     }
1507                 break;
1508
1509                 case 'site':
1510                     if ($mnetpeertheme) {
1511                         return $mnetpeertheme;
1512                     }
1513                     // First try for the device the user is using.
1514                     $devicetheme = get_selected_theme_for_device_type($this->devicetypeinuse);
1515                     if (!empty($devicetheme)) {
1516                         return $devicetheme;
1517                     }
1518                     // Next try for the default device (as a fallback)
1519                     $devicetheme = get_selected_theme_for_device_type('default');
1520                     if (!empty($devicetheme)) {
1521                         return $devicetheme;
1522                     }
1523                     // The default device theme isn't set up - use the overall default theme.
1524                     return theme_config::DEFAULT_THEME;
1525             }
1526         }
1527     }
1528
1529
1530     /**
1531      * Sets ->pagetype from the script name. For example, if the script that was
1532      * run is mod/quiz/view.php, ->pagetype will be set to 'mod-quiz-view'.
1533      *
1534      * @param string $script the path to the script that should be used to
1535      * initialise ->pagetype. If not passed the $SCRIPT global will be used.
1536      * If legacy code has set $CFG->pagepath that will be used instead, and a
1537      * developer warning issued.
1538      */
1539     protected function initialise_default_pagetype($script = null) {
1540         global $CFG, $SCRIPT;
1541
1542         if (isset($CFG->pagepath)) {
1543             debugging('Some code appears to have set $CFG->pagepath. That was a horrible deprecated thing. ' .
1544                     'Don\'t do it! Try calling $PAGE->set_pagetype() instead.');
1545             $script = $CFG->pagepath;
1546             unset($CFG->pagepath);
1547         }
1548
1549         if (is_null($script)) {
1550             $script = ltrim($SCRIPT, '/');
1551             $len = strlen($CFG->admin);
1552             if (substr($script, 0, $len) == $CFG->admin) {
1553                 $script = 'admin' . substr($script, $len);
1554             }
1555         }
1556
1557         $path = str_replace('.php', '', $script);
1558         if (substr($path, -1) == '/') {
1559             $path .= 'index';
1560         }
1561
1562         if (empty($path) || $path == 'index') {
1563             $this->_pagetype = 'site-index';
1564         } else {
1565             $this->_pagetype = str_replace('/', '-', $path);
1566         }
1567     }
1568
1569     /**
1570      * Initialises the CSS classes that will be added to body tag of the page.
1571      *
1572      * The function is responsible for adding all of the critical CSS classes
1573      * that describe the current page, and its state.
1574      * This includes classes that describe the following for example:
1575      *    - Current language
1576      *    - Language direction
1577      *    - YUI CSS initialisation
1578      *    - Pagelayout
1579      * These are commonly used in CSS to target specific types of pages.
1580      */
1581     protected function initialise_standard_body_classes() {
1582         global $CFG, $USER;
1583
1584         $pagetype = $this->pagetype;
1585         if ($pagetype == 'site-index') {
1586             $this->_legacyclass = 'course';
1587         } else if (substr($pagetype, 0, 6) == 'admin-') {
1588             $this->_legacyclass = 'admin';
1589         }
1590         $this->add_body_class($this->_legacyclass);
1591
1592         $pathbits = explode('-', trim($pagetype));
1593         for ($i=1;$i<count($pathbits);$i++) {
1594             $this->add_body_class('path-'.join('-',array_slice($pathbits, 0, $i)));
1595         }
1596
1597         $this->add_body_classes(get_browser_version_classes());
1598         $this->add_body_class('dir-' . get_string('thisdirection', 'langconfig'));
1599         $this->add_body_class('lang-' . current_language());
1600         $this->add_body_class('yui-skin-sam'); // Make YUI happy, if it is used.
1601         $this->add_body_class('yui3-skin-sam'); // Make YUI3 happy, if it is used.
1602         $this->add_body_class($this->url_to_class_name($CFG->wwwroot));
1603
1604         $this->add_body_class('pagelayout-' . $this->_pagelayout); // extra class describing current page layout
1605
1606         if (!during_initial_install()) {
1607             $this->add_body_class('course-' . $this->_course->id);
1608             $this->add_body_class('context-' . $this->_context->id);
1609         }
1610
1611         if (!empty($this->_cm)) {
1612             $this->add_body_class('cmid-' . $this->_cm->id);
1613         }
1614
1615         if (!empty($CFG->allowcategorythemes)) {
1616             $this->ensure_category_loaded();
1617             foreach ($this->_categories as $catid => $notused) {
1618                 $this->add_body_class('category-' . $catid);
1619             }
1620         } else {
1621             $catid = 0;
1622             if (is_array($this->_categories)) {
1623                 $catids = array_keys($this->_categories);
1624                 $catid = reset($catids);
1625             } else if (!empty($this->_course->category)) {
1626                 $catid = $this->_course->category;
1627             }
1628             if ($catid) {
1629                 $this->add_body_class('category-' . $catid);
1630             }
1631         }
1632
1633         if (!isloggedin()) {
1634             $this->add_body_class('notloggedin');
1635         }
1636
1637         if (!empty($USER->editing)) {
1638             $this->add_body_class('editing');
1639             if (optional_param('bui_moveid', false, PARAM_INT)) {
1640                $this->add_body_class('blocks-moving');
1641         }
1642         }
1643
1644         if (!empty($CFG->blocksdrag)) {
1645             $this->add_body_class('drag');
1646         }
1647
1648         if ($this->_devicetypeinuse != 'default') {
1649             $this->add_body_class($this->_devicetypeinuse . 'theme');
1650         }
1651     }
1652
1653     /**
1654      * Loads the activity record for the current CM object associated with this
1655      * page.
1656      *
1657      * This will load {@link moodle_page::$_module} with a row from the related
1658      * module table in the database.
1659      * For instance if {@link moodle_page::$_cm} is a forum then a row from the
1660      * forum table will be loaded.
1661      */
1662     protected function load_activity_record() {
1663         global $DB;
1664         if (is_null($this->_cm)) {
1665             return;
1666         }
1667         $this->_module = $DB->get_record($this->_cm->modname, array('id' => $this->_cm->instance));
1668     }
1669
1670     /**
1671      * This function ensures that the category of the current course has been
1672      * loaded, and if not, the function loads it now.
1673      *
1674      * @return void
1675      * @throws coding_exception
1676      */
1677     protected function ensure_category_loaded() {
1678         if (is_array($this->_categories)) {
1679             return; // Already done.
1680         }
1681         if (is_null($this->_course)) {
1682             throw new coding_exception('Attempt to get the course category for this page before the course was set.');
1683         }
1684         if ($this->_course->category == 0) {
1685             $this->_categories = array();
1686         } else {
1687             $this->load_category($this->_course->category);
1688         }
1689     }
1690
1691     /**
1692      * Loads the requested category into the pages categories array.
1693      *
1694      * @param ing $categoryid
1695      * @throws moodle_exception
1696      */
1697     protected function load_category($categoryid) {
1698         global $DB;
1699         $category = $DB->get_record('course_categories', array('id' => $categoryid));
1700         if (!$category) {
1701             throw new moodle_exception('unknowncategory');
1702         }
1703         $this->_categories[$category->id] = $category;
1704         $parentcategoryids = explode('/', trim($category->path, '/'));
1705         array_pop($parentcategoryids);
1706         foreach (array_reverse($parentcategoryids) as $catid) {
1707             $this->_categories[$catid] = null;
1708         }
1709     }
1710
1711     /**
1712      * Ensures that the category the current course is within, as well as all of
1713      * its parent categories, have been loaded.
1714      *
1715      * @return void
1716      */
1717     protected function ensure_categories_loaded() {
1718         global $DB;
1719         $this->ensure_category_loaded();
1720         if (!is_null(end($this->_categories))) {
1721             return; // Already done.
1722         }
1723         $idstoload = array_keys($this->_categories);
1724         array_shift($idstoload);
1725         $categories = $DB->get_records_list('course_categories', 'id', $idstoload);
1726         foreach ($idstoload as $catid) {
1727             $this->_categories[$catid] = $categories[$catid];
1728         }
1729     }
1730
1731     /**
1732      * Ensure the theme has not been loaded yet. If it has an exception is thrown.
1733      * @source
1734      *
1735      * @throws coding_exception
1736      */
1737     protected function ensure_theme_not_set() {
1738         if (!is_null($this->_theme)) {
1739             throw new coding_exception('The theme has already been set up for this page ready for output. ' .
1740                     'Therefore, you can no longer change the theme, or anything that might affect what ' .
1741                     'the current theme is, for example, the course.',
1742                     'Stack trace when the theme was set up: ' . format_backtrace($this->_wherethemewasinitialised));
1743         }
1744     }
1745
1746     /**
1747      * Converts the provided URL into a CSS class that be used within the page.
1748      * This is primarily used to add the wwwroot to the body tag as a CSS class.
1749      *
1750      * @param string $url
1751      * @return string
1752      */
1753     protected function url_to_class_name($url) {
1754         $bits = parse_url($url);
1755         $class = str_replace('.', '-', $bits['host']);
1756         if (!empty($bits['port'])) {
1757             $class .= '--' . $bits['port'];
1758         }
1759         if (!empty($bits['path'])) {
1760             $path = trim($bits['path'], '/');
1761             if ($path) {
1762                 $class .= '--' . str_replace('/', '-', $path);
1763             }
1764         }
1765         return $class;
1766     }
1767
1768     /**
1769      * Combines all of the required editing caps for the page and returns them
1770      * as an array.
1771      *
1772      * @return array
1773      */
1774     protected function all_editing_caps() {
1775         $caps = $this->_othereditingcaps;
1776         $caps[] = $this->_blockseditingcap;
1777         return $caps;
1778     }
1779
1780     /**
1781      * Returns true if the page URL has beem set.
1782      *
1783      * @return bool
1784      */
1785     public function has_set_url() {
1786         return ($this->_url!==null);
1787     }
1788
1789     /**
1790      * Gets set when the block actions for the page have been processed.
1791      *
1792      * @param bool $setting
1793      */
1794     public function set_block_actions_done($setting = true) {
1795         $this->_block_actions_done = $setting;
1796     }
1797
1798     /**
1799      * Are popup notifications allowed on this page?
1800      * Popup notifications may be disallowed in situations such as while upgrading or completing a quiz
1801      *
1802      * @return bool true if popup notifications may be displayed
1803      */
1804     public function get_popup_notification_allowed() {
1805         return $this->_popup_notification_allowed;
1806     }
1807
1808     /**
1809      * Allow or disallow popup notifications on this page. Popups are allowed by default.
1810      *
1811      * @param bool $allowed true if notifications are allowed. False if not allowed. They are allowed by default.
1812      */
1813     public function set_popup_notification_allowed($allowed) {
1814         $this->_popup_notification_allowed = $allowed;
1815     }
1816 }