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Developer Documentation
See Release Notes
Long Term Support Release
- Bug fixes for general core bugs in 4.1.x will end 13 November 2023 (12 months).
- Bug fixes for security issues in 4.1.x will end 10 November 2025 (36 months).
- PHP version: minimum PHP 7.4.0 Note: minimum PHP version has increased since Moodle 4.0. PHP 8.0.x is supported too.
/lib/ -> filterlib.php (source)
Differences Between: [Versions 310 and 401] [Versions 39 and 401] [Versions 401 and 402] [Versions 401 and 403]
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 for managing text filter plugins. 19 * 20 * @package core 21 * @copyright 1999 onwards Martin Dougiamas {@link http://moodle.com} 22 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later 23 */ 24 25 defined('MOODLE_INTERNAL') || die(); 26 27 /** The states a filter can be in, stored in the filter_active table. */ 28 define('TEXTFILTER_ON', 1); 29 /** The states a filter can be in, stored in the filter_active table. */ 30 define('TEXTFILTER_INHERIT', 0); 31 /** The states a filter can be in, stored in the filter_active table. */ 32 define('TEXTFILTER_OFF', -1); 33 /** The states a filter can be in, stored in the filter_active table. */ 34 define('TEXTFILTER_DISABLED', -9999); 35 36 /** 37 * Define one exclusive separator that we'll use in the temp saved tags 38 * keys. It must be something rare enough to avoid having matches with 39 * filterobjects. MDL-18165 40 */ 41 define('TEXTFILTER_EXCL_SEPARATOR', chr(0x1F) . '%' . chr(0x1F)); 42 43 44 /** 45 * Class to manage the filtering of strings. It is intended that this class is 46 * only used by weblib.php. Client code should probably be using the 47 * format_text and format_string functions. 48 * 49 * This class is a singleton. 50 * 51 * @copyright 1999 onwards Martin Dougiamas {@link http://moodle.com} 52 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later 53 */ 54 class filter_manager { 55 /** 56 * @var moodle_text_filter[][] This list of active filters, by context, for filtering content. 57 * An array contextid => ordered array of filter name => filter objects. 58 */ 59 protected $textfilters = array(); 60 61 /** 62 * @var moodle_text_filter[][] This list of active filters, by context, for filtering strings. 63 * An array contextid => ordered array of filter name => filter objects. 64 */ 65 protected $stringfilters = array(); 66 67 /** @var array Exploded version of $CFG->stringfilters. */ 68 protected $stringfilternames = array(); 69 70 /** @var filter_manager Holds the singleton instance. */ 71 protected static $singletoninstance; 72 73 /** 74 * Constructor. Protected. Use {@link instance()} instead. 75 */ 76 protected function __construct() { 77 $this->stringfilternames = filter_get_string_filters(); 78 } 79 80 /** 81 * Factory method. Use this to get the filter manager. 82 * 83 * @return filter_manager the singleton instance. 84 */ 85 public static function instance() { 86 global $CFG; 87 if (is_null(self::$singletoninstance)) { 88 if (!empty($CFG->perfdebug) and $CFG->perfdebug > 7) { 89 self::$singletoninstance = new performance_measuring_filter_manager(); 90 } else { 91 self::$singletoninstance = new self(); 92 } 93 } 94 return self::$singletoninstance; 95 } 96 97 /** 98 * Resets the caches, usually to be called between unit tests 99 */ 100 public static function reset_caches() { 101 if (self::$singletoninstance) { 102 self::$singletoninstance->unload_all_filters(); 103 } 104 self::$singletoninstance = null; 105 } 106 107 /** 108 * Unloads all filters and other cached information 109 */ 110 protected function unload_all_filters() { 111 $this->textfilters = array(); 112 $this->stringfilters = array(); 113 $this->stringfilternames = array(); 114 } 115 116 /** 117 * Load all the filters required by this context. 118 * 119 * @param context $context the context. 120 */ 121 protected function load_filters($context) { 122 $filters = filter_get_active_in_context($context); 123 $this->textfilters[$context->id] = array(); 124 $this->stringfilters[$context->id] = array(); 125 foreach ($filters as $filtername => $localconfig) { 126 $filter = $this->make_filter_object($filtername, $context, $localconfig); 127 if (is_null($filter)) { 128 continue; 129 } 130 $this->textfilters[$context->id][$filtername] = $filter; 131 if (in_array($filtername, $this->stringfilternames)) { 132 $this->stringfilters[$context->id][$filtername] = $filter; 133 } 134 } 135 } 136 137 /** 138 * Factory method for creating a filter. 139 * 140 * @param string $filtername The filter name, for example 'tex'. 141 * @param context $context context object. 142 * @param array $localconfig array of local configuration variables for this filter. 143 * @return moodle_text_filter The filter, or null, if this type of filter is 144 * not recognised or could not be created. 145 */ 146 protected function make_filter_object($filtername, $context, $localconfig) { 147 global $CFG; 148 $path = $CFG->dirroot .'/filter/'. $filtername .'/filter.php'; 149 if (!is_readable($path)) { 150 return null; 151 } 152 include_once($path); 153 154 $filterclassname = 'filter_' . $filtername; 155 if (class_exists($filterclassname)) { 156 return new $filterclassname($context, $localconfig); 157 } 158 159 return null; 160 } 161 162 /** 163 * Apply a list of filters to some content. 164 * @param string $text 165 * @param moodle_text_filter[] $filterchain array filter name => filter object. 166 * @param array $options options passed to the filters. 167 * @param array $skipfilters of filter names. Any filters that should not be applied to this text. 168 * @return string $text 169 */ 170 protected function apply_filter_chain($text, $filterchain, array $options = array(), 171 array $skipfilters = null) { 172 if (!isset($options['stage'])) { 173 $filtermethod = 'filter'; 174 } else if (in_array($options['stage'], ['pre_format', 'pre_clean', 'post_clean', 'string'], true)) { 175 $filtermethod = 'filter_stage_' . $options['stage']; 176 } else { 177 $filtermethod = 'filter'; 178 debugging('Invalid filter stage specified in options: ' . $options['stage'], DEBUG_DEVELOPER); 179 } 180 if ($text === null || $text === '') { 181 // Nothing to filter. 182 return ''; 183 } 184 foreach ($filterchain as $filtername => $filter) { 185 if ($skipfilters !== null && in_array($filtername, $skipfilters)) { 186 continue; 187 } 188 $text = $filter->$filtermethod($text, $options); 189 } 190 return $text; 191 } 192 193 /** 194 * Get all the filters that apply to a given context for calls to format_text. 195 * 196 * @param context $context 197 * @return moodle_text_filter[] A text filter 198 */ 199 protected function get_text_filters($context) { 200 if (!isset($this->textfilters[$context->id])) { 201 $this->load_filters($context); 202 } 203 return $this->textfilters[$context->id]; 204 } 205 206 /** 207 * Get all the filters that apply to a given context for calls to format_string. 208 * 209 * @param context $context the context. 210 * @return moodle_text_filter[] A text filter 211 */ 212 protected function get_string_filters($context) { 213 if (!isset($this->stringfilters[$context->id])) { 214 $this->load_filters($context); 215 } 216 return $this->stringfilters[$context->id]; 217 } 218 219 /** 220 * Filter some text 221 * 222 * @param string $text The text to filter 223 * @param context $context the context. 224 * @param array $options options passed to the filters 225 * @param array $skipfilters of filter names. Any filters that should not be applied to this text. 226 * @return string resulting text 227 */ 228 public function filter_text($text, $context, array $options = array(), 229 array $skipfilters = null) { 230 $text = $this->apply_filter_chain($text, $this->get_text_filters($context), $options, $skipfilters); 231 if (!isset($options['stage']) || $options['stage'] === 'post_clean') { 232 // Remove <nolink> tags for XHTML compatibility after the last filtering stage. 233 $text = str_replace(array('<nolink>', '</nolink>'), '', $text); 234 } 235 return $text; 236 } 237 238 /** 239 * Filter a piece of string 240 * 241 * @param string $string The text to filter 242 * @param context $context the context. 243 * @return string resulting string 244 */ 245 public function filter_string($string, $context) { 246 return $this->apply_filter_chain($string, $this->get_string_filters($context), ['stage' => 'string']); 247 } 248 249 /** 250 * @deprecated Since Moodle 3.0 MDL-50491. This was used by the old text filtering system, but no more. 251 */ 252 public function text_filtering_hash() { 253 throw new coding_exception('filter_manager::text_filtering_hash() can not be used any more'); 254 } 255 256 /** 257 * Setup page with filters requirements and other prepare stuff. 258 * 259 * This method is used by {@see format_text()} and {@see format_string()} 260 * in order to allow filters to setup any page requirement (js, css...) 261 * or perform any action needed to get them prepared before filtering itself 262 * happens by calling to each every active setup() method. 263 * 264 * Note it's executed for each piece of text filtered, so filter implementations 265 * are responsible of controlling the cardinality of the executions that may 266 * be different depending of the stuff to prepare. 267 * 268 * @param moodle_page $page the page we are going to add requirements to. 269 * @param context $context the context which contents are going to be filtered. 270 * @since Moodle 2.3 271 */ 272 public function setup_page_for_filters($page, $context) { 273 $filters = $this->get_text_filters($context); 274 foreach ($filters as $filter) { 275 $filter->setup($page, $context); 276 } 277 } 278 279 /** 280 * Setup the page for globally available filters. 281 * 282 * This helps setting up the page for filters which may be applied to 283 * the page, even if they do not belong to the current context, or are 284 * not yet visible because the content is lazily added (ajax). This method 285 * always uses to the system context which determines the globally 286 * available filters. 287 * 288 * This should only ever be called once per request. 289 * 290 * @param moodle_page $page The page. 291 * @since Moodle 3.2 292 */ 293 public function setup_page_for_globally_available_filters($page) { 294 $context = context_system::instance(); 295 $filterdata = filter_get_globally_enabled_filters_with_config(); 296 foreach ($filterdata as $name => $config) { 297 if (isset($this->textfilters[$context->id][$name])) { 298 $filter = $this->textfilters[$context->id][$name]; 299 } else { 300 $filter = $this->make_filter_object($name, $context, $config); 301 if (is_null($filter)) { 302 continue; 303 } 304 } 305 $filter->setup($page, $context); 306 } 307 } 308 } 309 310 311 /** 312 * Filter manager subclass that does nothing. Having this simplifies the logic 313 * of format_text, etc. 314 * 315 * @copyright 1999 onwards Martin Dougiamas {@link http://moodle.com} 316 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later 317 */ 318 class null_filter_manager { 319 /** 320 * As for the equivalent {@link filter_manager} method. 321 * 322 * @param string $text The text to filter 323 * @param context $context not used. 324 * @param array $options not used 325 * @param array $skipfilters not used 326 * @return string resulting text. 327 */ 328 public function filter_text($text, $context, array $options = array(), 329 array $skipfilters = null) { 330 return $text; 331 } 332 333 /** 334 * As for the equivalent {@link filter_manager} method. 335 * 336 * @param string $string The text to filter 337 * @param context $context not used. 338 * @return string resulting string 339 */ 340 public function filter_string($string, $context) { 341 return $string; 342 } 343 344 /** 345 * As for the equivalent {@link filter_manager} method. 346 * 347 * @deprecated Since Moodle 3.0 MDL-50491. 348 */ 349 public function text_filtering_hash() { 350 throw new coding_exception('filter_manager::text_filtering_hash() can not be used any more'); 351 } 352 } 353 354 355 /** 356 * Filter manager subclass that tracks how much work it does. 357 * 358 * @copyright 1999 onwards Martin Dougiamas {@link http://moodle.com} 359 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later 360 */ 361 class performance_measuring_filter_manager extends filter_manager { 362 /** @var int number of filter objects created. */ 363 protected $filterscreated = 0; 364 365 /** @var int number of calls to filter_text. */ 366 protected $textsfiltered = 0; 367 368 /** @var int number of calls to filter_string. */ 369 protected $stringsfiltered = 0; 370 371 protected function unload_all_filters() { 372 parent::unload_all_filters(); 373 $this->filterscreated = 0; 374 $this->textsfiltered = 0; 375 $this->stringsfiltered = 0; 376 } 377 378 protected function make_filter_object($filtername, $context, $localconfig) { 379 $this->filterscreated++; 380 return parent::make_filter_object($filtername, $context, $localconfig); 381 } 382 383 public function filter_text($text, $context, array $options = array(), 384 array $skipfilters = null) { 385 if (!isset($options['stage']) || $options['stage'] === 'post_clean') { 386 $this->textsfiltered++; 387 } 388 return parent::filter_text($text, $context, $options, $skipfilters); 389 } 390 391 public function filter_string($string, $context) { 392 $this->stringsfiltered++; 393 return parent::filter_string($string, $context); 394 } 395 396 /** 397 * Return performance information, in the form required by {@link get_performance_info()}. 398 * @return array the performance info. 399 */ 400 public function get_performance_summary() { 401 return array(array( 402 'contextswithfilters' => count($this->textfilters), 403 'filterscreated' => $this->filterscreated, 404 'textsfiltered' => $this->textsfiltered, 405 'stringsfiltered' => $this->stringsfiltered, 406 ), array( 407 'contextswithfilters' => 'Contexts for which filters were loaded', 408 'filterscreated' => 'Filters created', 409 'textsfiltered' => 'Pieces of content filtered', 410 'stringsfiltered' => 'Strings filtered', 411 )); 412 } 413 } 414 415 416 /** 417 * Base class for text filters. You just need to override this class and 418 * implement the filter method. 419 * 420 * @copyright 1999 onwards Martin Dougiamas {@link http://moodle.com} 421 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later 422 */ 423 abstract class moodle_text_filter { 424 /** @var context The context we are in. */ 425 protected $context; 426 427 /** @var array Any local configuration for this filter in this context. */ 428 protected $localconfig; 429 430 /** 431 * Set any context-specific configuration for this filter. 432 * 433 * @param context $context The current context. 434 * @param array $localconfig Any context-specific configuration for this filter. 435 */ 436 public function __construct($context, array $localconfig) { 437 $this->context = $context; 438 $this->localconfig = $localconfig; 439 } 440 441 /** 442 * @deprecated Since Moodle 3.0 MDL-50491. This was used by the old text filtering system, but no more. 443 */ 444 public function hash() { 445 throw new coding_exception('moodle_text_filter::hash() can not be used any more'); 446 } 447 448 /** 449 * Setup page with filter requirements and other prepare stuff. 450 * 451 * Override this method if the filter needs to setup page 452 * requirements or needs other stuff to be executed. 453 * 454 * Note this method is invoked from {@see setup_page_for_filters()} 455 * for each piece of text being filtered, so it is responsible 456 * for controlling its own execution cardinality. 457 * 458 * @param moodle_page $page the page we are going to add requirements to. 459 * @param context $context the context which contents are going to be filtered. 460 * @since Moodle 2.3 461 */ 462 public function setup($page, $context) { 463 // Override me, if needed. 464 } 465 466 /** 467 * Override this function to actually implement the filtering. 468 * 469 * Filter developers must make sure that filtering done after text cleaning 470 * does not introduce security vulnerabilities. 471 * 472 * @param string $text some HTML content to process. 473 * @param array $options options passed to the filters 474 * @return string the HTML content after the filtering has been applied. 475 */ 476 public abstract function filter($text, array $options = array()); 477 478 /** 479 * Filter text before changing format to HTML. 480 * 481 * @param string $text 482 * @param array $options 483 * @return string 484 */ 485 public function filter_stage_pre_format(string $text, array $options): string { 486 // NOTE: override if necessary. 487 return $text; 488 } 489 490 /** 491 * Filter HTML text before sanitising text. 492 * 493 * NOTE: this is called even if $options['noclean'] is true and text is not cleaned. 494 * 495 * @param string $text 496 * @param array $options 497 * @return string 498 */ 499 public function filter_stage_pre_clean(string $text, array $options): string { 500 // NOTE: override if necessary. 501 return $text; 502 } 503 504 /** 505 * Filter HTML text at the very end after text is sanitised. 506 * 507 * NOTE: this is called even if $options['noclean'] is true and text is not cleaned. 508 * 509 * @param string $text 510 * @param array $options 511 * @return string 512 */ 513 public function filter_stage_post_clean(string $text, array $options): string { 514 // NOTE: override if necessary. 515 return $this->filter($text, $options); 516 } 517 518 /** 519 * Filter simple text coming from format_string(). 520 * 521 * Note that unless $CFG->formatstringstriptags is disabled 522 * HTML tags are not expected in returned value. 523 * 524 * @param string $text 525 * @param array $options 526 * @return string 527 */ 528 public function filter_stage_string(string $text, array $options): string { 529 // NOTE: override if necessary. 530 return $this->filter($text, $options); 531 } 532 } 533 534 535 /** 536 * This is just a little object to define a phrase and some instructions 537 * for how to process it. Filters can create an array of these to pass 538 * to the @{link filter_phrases()} function below. 539 * 540 * Note that although the fields here are public, you almost certainly should 541 * never use that. All that is supported is contructing new instances of this 542 * class, and then passing an array of them to filter_phrases. 543 * 544 * @copyright 1999 onwards Martin Dougiamas {@link http://moodle.com} 545 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later 546 */ 547 class filterobject { 548 /** @var string this is the phrase that should be matched. */ 549 public $phrase; 550 551 /** @var bool whether to match complete words. If true, 'T' won't be matched in 'Tim'. */ 552 public $fullmatch; 553 554 /** @var bool whether the match needs to be case sensitive. */ 555 public $casesensitive; 556 557 /** @var string HTML to insert before any match. */ 558 public $hreftagbegin; 559 /** @var string HTML to insert after any match. */ 560 public $hreftagend; 561 562 /** @var null|string replacement text to go inside begin and end. If not set, 563 * the body of the replacement will be the original phrase. 564 */ 565 public $replacementphrase; 566 567 /** @var null|string once initialised, holds the regexp for matching this phrase. */ 568 public $workregexp = null; 569 570 /** @var null|string once initialised, holds the mangled HTML to replace the regexp with. */ 571 public $workreplacementphrase = null; 572 573 /** 574 * Constructor. 575 * 576 * @param string $phrase this is the phrase that should be matched. 577 * @param string $hreftagbegin HTML to insert before any match. Default '<span class="highlight">'. 578 * @param string $hreftagend HTML to insert after any match. Default '</span>'. 579 * @param bool $casesensitive whether the match needs to be case sensitive 580 * @param bool $fullmatch whether to match complete words. If true, 'T' won't be matched in 'Tim'. 581 * @param mixed $replacementphrase replacement text to go inside begin and end. If not set, 582 * the body of the replacement will be the original phrase. 583 * @param callback $replacementcallback if set, then this will be called just before 584 * $hreftagbegin, $hreftagend and $replacementphrase are needed, so they can be computed only if required. 585 * The call made is 586 * list($linkobject->hreftagbegin, $linkobject->hreftagend, $linkobject->replacementphrase) = 587 * call_user_func_array($linkobject->replacementcallback, $linkobject->replacementcallbackdata); 588 * so the return should be an array [$hreftagbegin, $hreftagend, $replacementphrase], the last of which may be null. 589 * @param array $replacementcallbackdata data to be passed to $replacementcallback (optional). 590 */ 591 public function __construct($phrase, $hreftagbegin = '<span class="highlight">', 592 $hreftagend = '</span>', 593 $casesensitive = false, 594 $fullmatch = false, 595 $replacementphrase = null, 596 $replacementcallback = null, 597 array $replacementcallbackdata = null) { 598 599 $this->phrase = $phrase; 600 $this->hreftagbegin = $hreftagbegin; 601 $this->hreftagend = $hreftagend; 602 $this->casesensitive = !empty($casesensitive); 603 $this->fullmatch = !empty($fullmatch); 604 $this->replacementphrase = $replacementphrase; 605 $this->replacementcallback = $replacementcallback; 606 $this->replacementcallbackdata = $replacementcallbackdata; 607 } 608 } 609 610 /** 611 * Look up the name of this filter 612 * 613 * @param string $filter the filter name 614 * @return string the human-readable name for this filter. 615 */ 616 function filter_get_name($filter) { 617 if (strpos($filter, 'filter/') === 0) { 618 debugging("Old '$filter'' parameter used in filter_get_name()"); 619 $filter = substr($filter, 7); 620 } else if (strpos($filter, '/') !== false) { 621 throw new coding_exception('Unknown filter type ' . $filter); 622 } 623 624 if (get_string_manager()->string_exists('filtername', 'filter_' . $filter)) { 625 return get_string('filtername', 'filter_' . $filter); 626 } else { 627 return $filter; 628 } 629 } 630 631 /** 632 * Get the names of all the filters installed in this Moodle. 633 * 634 * @return array path => filter name from the appropriate lang file. e.g. 635 * array('tex' => 'TeX Notation'); 636 * sorted in alphabetical order of name. 637 */ 638 function filter_get_all_installed() { 639 $filternames = array(); 640 foreach (core_component::get_plugin_list('filter') as $filter => $fulldir) { 641 if (is_readable("$fulldir/filter.php")) { 642 $filternames[$filter] = filter_get_name($filter); 643 } 644 } 645 core_collator::asort($filternames); 646 return $filternames; 647 } 648 649 /** 650 * Set the global activated state for a text filter. 651 * 652 * @param string $filtername The filter name, for example 'tex'. 653 * @param int $state One of the values TEXTFILTER_ON, TEXTFILTER_OFF or TEXTFILTER_DISABLED. 654 * @param int $move -1 means up, 0 means the same, 1 means down 655 */ 656 function filter_set_global_state($filtername, $state, $move = 0) { 657 global $DB; 658 659 // Check requested state is valid. 660 if (!in_array($state, array(TEXTFILTER_ON, TEXTFILTER_OFF, TEXTFILTER_DISABLED))) { 661 throw new coding_exception("Illegal option '$state' passed to filter_set_global_state. " . 662 "Must be one of TEXTFILTER_ON, TEXTFILTER_OFF or TEXTFILTER_DISABLED."); 663 } 664 665 if ($move > 0) { 666 $move = 1; 667 } else if ($move < 0) { 668 $move = -1; 669 } 670 671 if (strpos($filtername, 'filter/') === 0) { 672 $filtername = substr($filtername, 7); 673 } else if (strpos($filtername, '/') !== false) { 674 throw new coding_exception("Invalid filter name '$filtername' used in filter_set_global_state()"); 675 } 676 677 $transaction = $DB->start_delegated_transaction(); 678 679 $syscontext = context_system::instance(); 680 $filters = $DB->get_records('filter_active', array('contextid' => $syscontext->id), 'sortorder ASC'); 681 682 $on = array(); 683 $off = array(); 684 685 foreach ($filters as $f) { 686 if ($f->active == TEXTFILTER_DISABLED) { 687 $off[$f->filter] = $f; 688 } else { 689 $on[$f->filter] = $f; 690 } 691 } 692 693 // Update the state or add new record. 694 if (isset($on[$filtername])) { 695 $filter = $on[$filtername]; 696 if ($filter->active != $state) { 697 add_to_config_log('filter_active', $filter->active, $state, $filtername); 698 699 $filter->active = $state; 700 $DB->update_record('filter_active', $filter); 701 if ($filter->active == TEXTFILTER_DISABLED) { 702 unset($on[$filtername]); 703 $off = array($filter->filter => $filter) + $off; 704 } 705 706 } 707 708 } else if (isset($off[$filtername])) { 709 $filter = $off[$filtername]; 710 if ($filter->active != $state) { 711 add_to_config_log('filter_active', $filter->active, $state, $filtername); 712 713 $filter->active = $state; 714 $DB->update_record('filter_active', $filter); 715 if ($filter->active != TEXTFILTER_DISABLED) { 716 unset($off[$filtername]); 717 $on[$filter->filter] = $filter; 718 } 719 } 720 721 } else { 722 add_to_config_log('filter_active', '', $state, $filtername); 723 724 $filter = new stdClass(); 725 $filter->filter = $filtername; 726 $filter->contextid = $syscontext->id; 727 $filter->active = $state; 728 $filter->sortorder = 99999; 729 $filter->id = $DB->insert_record('filter_active', $filter); 730 731 $filters[$filter->id] = $filter; 732 if ($state == TEXTFILTER_DISABLED) { 733 $off[$filter->filter] = $filter; 734 } else { 735 $on[$filter->filter] = $filter; 736 } 737 } 738 739 // Move only active. 740 if ($move != 0 and isset($on[$filter->filter])) { 741 // Capture the old order for logging. 742 $oldorder = implode(', ', array_map( 743 function($f) { 744 return $f->filter; 745 }, $on)); 746 747 // Work out the new order. 748 $i = 1; 749 foreach ($on as $f) { 750 $f->newsortorder = $i; 751 $i++; 752 } 753 754 $filter->newsortorder = $filter->newsortorder + $move; 755 756 foreach ($on as $f) { 757 if ($f->id == $filter->id) { 758 continue; 759 } 760 if ($f->newsortorder == $filter->newsortorder) { 761 if ($move == 1) { 762 $f->newsortorder = $f->newsortorder - 1; 763 } else { 764 $f->newsortorder = $f->newsortorder + 1; 765 } 766 } 767 } 768 769 core_collator::asort_objects_by_property($on, 'newsortorder', core_collator::SORT_NUMERIC); 770 771 // Log in config_log. 772 $neworder = implode(', ', array_map( 773 function($f) { 774 return $f->filter; 775 }, $on)); 776 add_to_config_log('order', $oldorder, $neworder, 'core_filter'); 777 } 778 779 // Inactive are sorted by filter name. 780 core_collator::asort_objects_by_property($off, 'filter', core_collator::SORT_NATURAL); 781 782 // Update records if necessary. 783 $i = 1; 784 foreach ($on as $f) { 785 if ($f->sortorder != $i) { 786 $DB->set_field('filter_active', 'sortorder', $i, array('id' => $f->id)); 787 } 788 $i++; 789 } 790 foreach ($off as $f) { 791 if ($f->sortorder != $i) { 792 $DB->set_field('filter_active', 'sortorder', $i, array('id' => $f->id)); 793 } 794 $i++; 795 } 796 797 $transaction->allow_commit(); 798 } 799 800 /** 801 * Returns the active state for a filter in the given context. 802 * 803 * @param string $filtername The filter name, for example 'tex'. 804 * @param integer $contextid The id of the context to get the data for. 805 * @return int value of active field for the given filter. 806 */ 807 function filter_get_active_state(string $filtername, $contextid = null): int { 808 global $DB; 809 810 if ($contextid === null) { 811 $contextid = context_system::instance()->id; 812 } 813 if (is_object($contextid)) { 814 $contextid = $contextid->id; 815 } 816 817 if (strpos($filtername, 'filter/') === 0) { 818 $filtername = substr($filtername, 7); 819 } else if (strpos($filtername, '/') !== false) { 820 throw new coding_exception("Invalid filter name '$filtername' used in filter_is_enabled()"); 821 } 822 if ($active = $DB->get_field('filter_active', 'active', array('filter' => $filtername, 'contextid' => $contextid))) { 823 return $active; 824 } 825 826 return TEXTFILTER_DISABLED; 827 } 828 829 /** 830 * @param string $filtername The filter name, for example 'tex'. 831 * @return boolean is this filter allowed to be used on this site. That is, the 832 * admin has set the global 'active' setting to On, or Off, but available. 833 */ 834 function filter_is_enabled($filtername) { 835 if (strpos($filtername, 'filter/') === 0) { 836 $filtername = substr($filtername, 7); 837 } else if (strpos($filtername, '/') !== false) { 838 throw new coding_exception("Invalid filter name '$filtername' used in filter_is_enabled()"); 839 } 840 return array_key_exists($filtername, filter_get_globally_enabled()); 841 } 842 843 /** 844 * Return a list of all the filters that may be in use somewhere. 845 * 846 * @return array where the keys and values are both the filter name, like 'tex'. 847 */ 848 function filter_get_globally_enabled() { 849 $cache = \cache::make_from_params(\cache_store::MODE_REQUEST, 'core_filter', 'global_filters'); 850 $enabledfilters = $cache->get('enabled'); 851 if ($enabledfilters !== false) { 852 return $enabledfilters; 853 } 854 855 $filters = filter_get_global_states(); 856 $enabledfilters = array(); 857 foreach ($filters as $filter => $filerinfo) { 858 if ($filerinfo->active != TEXTFILTER_DISABLED) { 859 $enabledfilters[$filter] = $filter; 860 } 861 } 862 863 $cache->set('enabled', $enabledfilters); 864 return $enabledfilters; 865 } 866 867 /** 868 * Get the globally enabled filters. 869 * 870 * This returns the filters which could be used in any context. Essentially 871 * the filters which are not disabled for the entire site. 872 * 873 * @return array Keys are filter names, and values the config. 874 */ 875 function filter_get_globally_enabled_filters_with_config() { 876 global $DB; 877 878 $sql = "SELECT f.filter, fc.name, fc.value 879 FROM {filter_active} f 880 LEFT JOIN {filter_config} fc 881 ON fc.filter = f.filter 882 AND fc.contextid = f.contextid 883 WHERE f.contextid = :contextid 884 AND f.active != :disabled 885 ORDER BY f.sortorder"; 886 887 $rs = $DB->get_recordset_sql($sql, [ 888 'contextid' => context_system::instance()->id, 889 'disabled' => TEXTFILTER_DISABLED 890 ]); 891 892 // Massage the data into the specified format to return. 893 $filters = array(); 894 foreach ($rs as $row) { 895 if (!isset($filters[$row->filter])) { 896 $filters[$row->filter] = array(); 897 } 898 if ($row->name !== null) { 899 $filters[$row->filter][$row->name] = $row->value; 900 } 901 } 902 $rs->close(); 903 904 return $filters; 905 } 906 907 /** 908 * Return the names of the filters that should also be applied to strings 909 * (when they are enabled). 910 * 911 * @return array where the keys and values are both the filter name, like 'tex'. 912 */ 913 function filter_get_string_filters() { 914 global $CFG; 915 $stringfilters = array(); 916 if (!empty($CFG->filterall) && !empty($CFG->stringfilters)) { 917 $stringfilters = explode(',', $CFG->stringfilters); 918 $stringfilters = array_combine($stringfilters, $stringfilters); 919 } 920 return $stringfilters; 921 } 922 923 /** 924 * Sets whether a particular active filter should be applied to all strings by 925 * format_string, or just used by format_text. 926 * 927 * @param string $filter The filter name, for example 'tex'. 928 * @param boolean $applytostrings if true, this filter will apply to format_string 929 * and format_text, when it is enabled. 930 */ 931 function filter_set_applies_to_strings($filter, $applytostrings) { 932 $stringfilters = filter_get_string_filters(); 933 $prevfilters = $stringfilters; 934 $allfilters = core_component::get_plugin_list('filter'); 935 936 if ($applytostrings) { 937 $stringfilters[$filter] = $filter; 938 } else { 939 unset($stringfilters[$filter]); 940 } 941 942 // Remove missing filters. 943 foreach ($stringfilters as $filter) { 944 if (!isset($allfilters[$filter])) { 945 unset($stringfilters[$filter]); 946 } 947 } 948 949 if ($prevfilters != $stringfilters) { 950 set_config('stringfilters', implode(',', $stringfilters)); 951 set_config('filterall', !empty($stringfilters)); 952 } 953 } 954 955 /** 956 * Set the local activated state for a text filter. 957 * 958 * @param string $filter The filter name, for example 'tex'. 959 * @param integer $contextid The id of the context to get the local config for. 960 * @param integer $state One of the values TEXTFILTER_ON, TEXTFILTER_OFF or TEXTFILTER_INHERIT. 961 * @return void 962 */ 963 function filter_set_local_state($filter, $contextid, $state) { 964 global $DB; 965 966 // Check requested state is valid. 967 if (!in_array($state, array(TEXTFILTER_ON, TEXTFILTER_OFF, TEXTFILTER_INHERIT))) { 968 throw new coding_exception("Illegal option '$state' passed to filter_set_local_state. " . 969 "Must be one of TEXTFILTER_ON, TEXTFILTER_OFF or TEXTFILTER_INHERIT."); 970 } 971 972 if ($contextid == context_system::instance()->id) { 973 throw new coding_exception('You cannot use filter_set_local_state ' . 974 'with $contextid equal to the system context id.'); 975 } 976 977 if ($state == TEXTFILTER_INHERIT) { 978 $DB->delete_records('filter_active', array('filter' => $filter, 'contextid' => $contextid)); 979 return; 980 } 981 982 $rec = $DB->get_record('filter_active', array('filter' => $filter, 'contextid' => $contextid)); 983 $insert = false; 984 if (empty($rec)) { 985 $insert = true; 986 $rec = new stdClass; 987 $rec->filter = $filter; 988 $rec->contextid = $contextid; 989 } 990 991 $rec->active = $state; 992 993 if ($insert) { 994 $DB->insert_record('filter_active', $rec); 995 } else { 996 $DB->update_record('filter_active', $rec); 997 } 998 } 999 1000 /** 1001 * Set a particular local config variable for a filter in a context. 1002 * 1003 * @param string $filter The filter name, for example 'tex'. 1004 * @param integer $contextid The id of the context to get the local config for. 1005 * @param string $name the setting name. 1006 * @param string $value the corresponding value. 1007 */ 1008 function filter_set_local_config($filter, $contextid, $name, $value) { 1009 global $DB; 1010 $rec = $DB->get_record('filter_config', array('filter' => $filter, 'contextid' => $contextid, 'name' => $name)); 1011 $insert = false; 1012 if (empty($rec)) { 1013 $insert = true; 1014 $rec = new stdClass; 1015 $rec->filter = $filter; 1016 $rec->contextid = $contextid; 1017 $rec->name = $name; 1018 } 1019 1020 $rec->value = $value; 1021 1022 if ($insert) { 1023 $DB->insert_record('filter_config', $rec); 1024 } else { 1025 $DB->update_record('filter_config', $rec); 1026 } 1027 } 1028 1029 /** 1030 * Remove a particular local config variable for a filter in a context. 1031 * 1032 * @param string $filter The filter name, for example 'tex'. 1033 * @param integer $contextid The id of the context to get the local config for. 1034 * @param string $name the setting name. 1035 */ 1036 function filter_unset_local_config($filter, $contextid, $name) { 1037 global $DB; 1038 $DB->delete_records('filter_config', array('filter' => $filter, 'contextid' => $contextid, 'name' => $name)); 1039 } 1040 1041 /** 1042 * Get local config variables for a filter in a context. Normally (when your 1043 * filter is running) you don't need to call this, becuase the config is fetched 1044 * for you automatically. You only need this, for example, when you are getting 1045 * the config so you can show the user an editing from. 1046 * 1047 * @param string $filter The filter name, for example 'tex'. 1048 * @param integer $contextid The ID of the context to get the local config for. 1049 * @return array of name => value pairs. 1050 */ 1051 function filter_get_local_config($filter, $contextid) { 1052 global $DB; 1053 return $DB->get_records_menu('filter_config', array('filter' => $filter, 'contextid' => $contextid), '', 'name,value'); 1054 } 1055 1056 /** 1057 * This function is for use by backup. Gets all the filter information specific 1058 * to one context. 1059 * 1060 * @param int $contextid 1061 * @return array Array with two elements. The first element is an array of objects with 1062 * fields filter and active. These come from the filter_active table. The 1063 * second element is an array of objects with fields filter, name and value 1064 * from the filter_config table. 1065 */ 1066 function filter_get_all_local_settings($contextid) { 1067 global $DB; 1068 return array( 1069 $DB->get_records('filter_active', array('contextid' => $contextid), 'filter', 'filter,active'), 1070 $DB->get_records('filter_config', array('contextid' => $contextid), 'filter,name', 'filter,name,value'), 1071 ); 1072 } 1073 1074 /** 1075 * Get the list of active filters, in the order that they should be used 1076 * for a particular context, along with any local configuration variables. 1077 * 1078 * @param context $context a context 1079 * @return array an array where the keys are the filter names, for example 1080 * 'tex' and the values are any local 1081 * configuration for that filter, as an array of name => value pairs 1082 * from the filter_config table. In a lot of cases, this will be an 1083 * empty array. So, an example return value for this function might be 1084 * array(tex' => array()) 1085 */ 1086 function filter_get_active_in_context($context) { 1087 global $DB, $FILTERLIB_PRIVATE; 1088 1089 if (!isset($FILTERLIB_PRIVATE)) { 1090 $FILTERLIB_PRIVATE = new stdClass(); 1091 } 1092 1093 // Use cache (this is a within-request cache only) if available. See 1094 // function filter_preload_activities. 1095 if (isset($FILTERLIB_PRIVATE->active) && 1096 array_key_exists($context->id, $FILTERLIB_PRIVATE->active)) { 1097 return $FILTERLIB_PRIVATE->active[$context->id]; 1098 } 1099 1100 $contextids = str_replace('/', ',', trim($context->path, '/')); 1101 1102 // The following SQL is tricky. It is explained on 1103 // http://docs.moodle.org/dev/Filter_enable/disable_by_context. 1104 $sql = "SELECT active.filter, fc.name, fc.value 1105 FROM (SELECT f.filter, MAX(f.sortorder) AS sortorder 1106 FROM {filter_active} f 1107 JOIN {context} ctx ON f.contextid = ctx.id 1108 WHERE ctx.id IN ($contextids) 1109 GROUP BY filter 1110 HAVING MAX(f.active * ctx.depth) > -MIN(f.active * ctx.depth) 1111 ) active 1112 LEFT JOIN {filter_config} fc ON fc.filter = active.filter AND fc.contextid = $context->id 1113 ORDER BY active.sortorder"; 1114 $rs = $DB->get_recordset_sql($sql); 1115 1116 // Massage the data into the specified format to return. 1117 $filters = array(); 1118 foreach ($rs as $row) { 1119 if (!isset($filters[$row->filter])) { 1120 $filters[$row->filter] = array(); 1121 } 1122 if (!is_null($row->name)) { 1123 $filters[$row->filter][$row->name] = $row->value; 1124 } 1125 } 1126 1127 $rs->close(); 1128 1129 return $filters; 1130 } 1131 1132 /** 1133 * Preloads the list of active filters for all activities (modules) on the course 1134 * using two database queries. 1135 * 1136 * @param course_modinfo $modinfo Course object from get_fast_modinfo 1137 */ 1138 function filter_preload_activities(course_modinfo $modinfo) { 1139 global $DB, $FILTERLIB_PRIVATE; 1140 1141 if (!isset($FILTERLIB_PRIVATE)) { 1142 $FILTERLIB_PRIVATE = new stdClass(); 1143 } 1144 1145 // Don't repeat preload. 1146 if (!isset($FILTERLIB_PRIVATE->preloaded)) { 1147 $FILTERLIB_PRIVATE->preloaded = array(); 1148 } 1149 if (!empty($FILTERLIB_PRIVATE->preloaded[$modinfo->get_course_id()])) { 1150 return; 1151 } 1152 $FILTERLIB_PRIVATE->preloaded[$modinfo->get_course_id()] = true; 1153 1154 // Get contexts for all CMs. 1155 $cmcontexts = array(); 1156 $cmcontextids = array(); 1157 foreach ($modinfo->get_cms() as $cm) { 1158 $modulecontext = context_module::instance($cm->id); 1159 $cmcontextids[] = $modulecontext->id; 1160 $cmcontexts[] = $modulecontext; 1161 } 1162 1163 // Get course context and all other parents. 1164 $coursecontext = context_course::instance($modinfo->get_course_id()); 1165 $parentcontextids = explode('/', substr($coursecontext->path, 1)); 1166 $allcontextids = array_merge($cmcontextids, $parentcontextids); 1167 1168 // Get all filter_active rows relating to all these contexts. 1169 list ($sql, $params) = $DB->get_in_or_equal($allcontextids); 1170 $filteractives = $DB->get_records_select('filter_active', "contextid $sql", $params, 'sortorder'); 1171 1172 // Get all filter_config only for the cm contexts. 1173 list ($sql, $params) = $DB->get_in_or_equal($cmcontextids); 1174 $filterconfigs = $DB->get_records_select('filter_config', "contextid $sql", $params); 1175 1176 // Note: I was a bit surprised that filter_config only works for the 1177 // most specific context (i.e. it does not need to be checked for course 1178 // context if we only care about CMs) however basede on code in 1179 // filter_get_active_in_context, this does seem to be correct. 1180 1181 // Build course default active list. Initially this will be an array of 1182 // filter name => active score (where an active score >0 means it's active). 1183 $courseactive = array(); 1184 1185 // Also build list of filter_active rows below course level, by contextid. 1186 $remainingactives = array(); 1187 1188 // Array lists filters that are banned at top level. 1189 $banned = array(); 1190 1191 // Add any active filters in parent contexts to the array. 1192 foreach ($filteractives as $row) { 1193 $depth = array_search($row->contextid, $parentcontextids); 1194 if ($depth !== false) { 1195 // Find entry. 1196 if (!array_key_exists($row->filter, $courseactive)) { 1197 $courseactive[$row->filter] = 0; 1198 } 1199 // This maths copes with reading rows in any order. Turning on/off 1200 // at site level counts 1, at next level down 4, at next level 9, 1201 // then 16, etc. This means the deepest level always wins, except 1202 // against the -9999 at top level. 1203 $courseactive[$row->filter] += 1204 ($depth + 1) * ($depth + 1) * $row->active; 1205 1206 if ($row->active == TEXTFILTER_DISABLED) { 1207 $banned[$row->filter] = true; 1208 } 1209 } else { 1210 // Build list of other rows indexed by contextid. 1211 if (!array_key_exists($row->contextid, $remainingactives)) { 1212 $remainingactives[$row->contextid] = array(); 1213 } 1214 $remainingactives[$row->contextid][] = $row; 1215 } 1216 } 1217 1218 // Chuck away the ones that aren't active. 1219 foreach ($courseactive as $filter => $score) { 1220 if ($score <= 0) { 1221 unset($courseactive[$filter]); 1222 } else { 1223 $courseactive[$filter] = array(); 1224 } 1225 } 1226 1227 // Loop through the contexts to reconstruct filter_active lists for each 1228 // cm on the course. 1229 if (!isset($FILTERLIB_PRIVATE->active)) { 1230 $FILTERLIB_PRIVATE->active = array(); 1231 } 1232 foreach ($cmcontextids as $contextid) { 1233 // Copy course list. 1234 $FILTERLIB_PRIVATE->active[$contextid] = $courseactive; 1235 1236 // Are there any changes to the active list? 1237 if (array_key_exists($contextid, $remainingactives)) { 1238 foreach ($remainingactives[$contextid] as $row) { 1239 if ($row->active > 0 && empty($banned[$row->filter])) { 1240 // If it's marked active for specific context, add entry 1241 // (doesn't matter if one exists already). 1242 $FILTERLIB_PRIVATE->active[$contextid][$row->filter] = array(); 1243 } else { 1244 // If it's marked inactive, remove entry (doesn't matter 1245 // if it doesn't exist). 1246 unset($FILTERLIB_PRIVATE->active[$contextid][$row->filter]); 1247 } 1248 } 1249 } 1250 } 1251 1252 // Process all config rows to add config data to these entries. 1253 foreach ($filterconfigs as $row) { 1254 if (isset($FILTERLIB_PRIVATE->active[$row->contextid][$row->filter])) { 1255 $FILTERLIB_PRIVATE->active[$row->contextid][$row->filter][$row->name] = $row->value; 1256 } 1257 } 1258 } 1259 1260 /** 1261 * List all of the filters that are available in this context, and what the 1262 * local and inherited states of that filter are. 1263 * 1264 * @param context $context a context that is not the system context. 1265 * @return array an array with filter names, for example 'tex' 1266 * as keys. and and the values are objects with fields: 1267 * ->filter filter name, same as the key. 1268 * ->localstate TEXTFILTER_ON/OFF/INHERIT 1269 * ->inheritedstate TEXTFILTER_ON/OFF - the state that will be used if localstate is set to TEXTFILTER_INHERIT. 1270 */ 1271 function filter_get_available_in_context($context) { 1272 global $DB; 1273 1274 // The complex logic is working out the active state in the parent context, 1275 // so strip the current context from the list. 1276 $contextids = explode('/', trim($context->path, '/')); 1277 array_pop($contextids); 1278 $contextids = implode(',', $contextids); 1279 if (empty($contextids)) { 1280 throw new coding_exception('filter_get_available_in_context cannot be called with the system context.'); 1281 } 1282 1283 // The following SQL is tricky, in the same way at the SQL in filter_get_active_in_context. 1284 $sql = "SELECT parent_states.filter, 1285 CASE WHEN fa.active IS NULL THEN " . TEXTFILTER_INHERIT . " 1286 ELSE fa.active END AS localstate, 1287 parent_states.inheritedstate 1288 FROM (SELECT f.filter, MAX(f.sortorder) AS sortorder, 1289 CASE WHEN MAX(f.active * ctx.depth) > -MIN(f.active * ctx.depth) THEN " . TEXTFILTER_ON . " 1290 ELSE " . TEXTFILTER_OFF . " END AS inheritedstate 1291 FROM {filter_active} f 1292 JOIN {context} ctx ON f.contextid = ctx.id 1293 WHERE ctx.id IN ($contextids) 1294 GROUP BY f.filter 1295 HAVING MIN(f.active) > " . TEXTFILTER_DISABLED . " 1296 ) parent_states 1297 LEFT JOIN {filter_active} fa ON fa.filter = parent_states.filter AND fa.contextid = $context->id 1298 ORDER BY parent_states.sortorder"; 1299 return $DB->get_records_sql($sql); 1300 } 1301 1302 /** 1303 * This function is for use by the filter administration page. 1304 * 1305 * @return array 'filtername' => object with fields 'filter' (=filtername), 'active' and 'sortorder' 1306 */ 1307 function filter_get_global_states() { 1308 global $DB; 1309 $context = context_system::instance(); 1310 return $DB->get_records('filter_active', array('contextid' => $context->id), 'sortorder', 'filter,active,sortorder'); 1311 } 1312 1313 /** 1314 * Delete all the data in the database relating to a filter, prior to deleting it. 1315 * 1316 * @param string $filter The filter name, for example 'tex'. 1317 */ 1318 function filter_delete_all_for_filter($filter) { 1319 global $DB; 1320 1321 unset_all_config_for_plugin('filter_' . $filter); 1322 $DB->delete_records('filter_active', array('filter' => $filter)); 1323 $DB->delete_records('filter_config', array('filter' => $filter)); 1324 } 1325 1326 /** 1327 * Delete all the data in the database relating to a context, used when contexts are deleted. 1328 * 1329 * @param integer $contextid The id of the context being deleted. 1330 */ 1331 function filter_delete_all_for_context($contextid) { 1332 global $DB; 1333 $DB->delete_records('filter_active', array('contextid' => $contextid)); 1334 $DB->delete_records('filter_config', array('contextid' => $contextid)); 1335 } 1336 1337 /** 1338 * Does this filter have a global settings page in the admin tree? 1339 * (The settings page for a filter must be called, for example, filtersettingfiltertex.) 1340 * 1341 * @param string $filter The filter name, for example 'tex'. 1342 * @return boolean Whether there should be a 'Settings' link on the config page. 1343 */ 1344 function filter_has_global_settings($filter) { 1345 global $CFG; 1346 $settingspath = $CFG->dirroot . '/filter/' . $filter . '/settings.php'; 1347 if (is_readable($settingspath)) { 1348 return true; 1349 } 1350 $settingspath = $CFG->dirroot . '/filter/' . $filter . '/filtersettings.php'; 1351 return is_readable($settingspath); 1352 } 1353 1354 /** 1355 * Does this filter have local (per-context) settings? 1356 * 1357 * @param string $filter The filter name, for example 'tex'. 1358 * @return boolean Whether there should be a 'Settings' link on the manage filters in context page. 1359 */ 1360 function filter_has_local_settings($filter) { 1361 global $CFG; 1362 $settingspath = $CFG->dirroot . '/filter/' . $filter . '/filterlocalsettings.php'; 1363 return is_readable($settingspath); 1364 } 1365 1366 /** 1367 * Certain types of context (block and user) may not have local filter settings. 1368 * the function checks a context to see whether it may have local config. 1369 * 1370 * @param object $context a context. 1371 * @return boolean whether this context may have local filter settings. 1372 */ 1373 function filter_context_may_have_filter_settings($context) { 1374 return $context->contextlevel != CONTEXT_BLOCK && $context->contextlevel != CONTEXT_USER; 1375 } 1376 1377 /** 1378 * Process phrases intelligently found within a HTML text (such as adding links). 1379 * 1380 * @param string $text the text that we are filtering 1381 * @param filterobject[] $linkarray an array of filterobjects 1382 * @param array $ignoretagsopen an array of opening tags that we should ignore while filtering 1383 * @param array $ignoretagsclose an array of corresponding closing tags 1384 * @param bool $overridedefaultignore True to only use tags provided by arguments 1385 * @param bool $linkarrayalreadyprepared True to say that filter_prepare_phrases_for_filtering 1386 * has already been called for $linkarray. Default false. 1387 * @return string 1388 */ 1389 function filter_phrases($text, $linkarray, $ignoretagsopen = null, $ignoretagsclose = null, 1390 $overridedefaultignore = false, $linkarrayalreadyprepared = false) { 1391 1392 global $CFG; 1393 1394 // Used if $CFG->filtermatchoneperpage is on. Array with keys being the workregexp 1395 // for things that have already been matched on this page. 1396 static $usedphrases = []; 1397 1398 $ignoretags = array(); // To store all the enclosing tags to be completely ignored. 1399 $tags = array(); // To store all the simple tags to be ignored. 1400 1401 if (!$linkarrayalreadyprepared) { 1402 $linkarray = filter_prepare_phrases_for_filtering($linkarray); 1403 } 1404 1405 if (!$overridedefaultignore) { 1406 // A list of open/close tags that we should not replace within. 1407 // Extended to include <script>, <textarea>, <select> and <a> tags. 1408 // Regular expression allows tags with or without attributes. 1409 $filterignoretagsopen = array('<head>', '<nolink>', '<span(\s[^>]*?)?class="nolink"(\s[^>]*?)?>', 1410 '<script(\s[^>]*?)?>', '<textarea(\s[^>]*?)?>', 1411 '<select(\s[^>]*?)?>', '<a(\s[^>]*?)?>'); 1412 $filterignoretagsclose = array('</head>', '</nolink>', '</span>', 1413 '</script>', '</textarea>', '</select>', '</a>'); 1414 } else { 1415 // Set an empty default list. 1416 $filterignoretagsopen = array(); 1417 $filterignoretagsclose = array(); 1418 } 1419 1420 // Add the user defined ignore tags to the default list. 1421 if ( is_array($ignoretagsopen) ) { 1422 foreach ($ignoretagsopen as $open) { 1423 $filterignoretagsopen[] = $open; 1424 } 1425 foreach ($ignoretagsclose as $close) { 1426 $filterignoretagsclose[] = $close; 1427 } 1428 } 1429 1430 // Double up some magic chars to avoid "accidental matches". 1431 $text = preg_replace('/([#*%])/', '\1\1', $text); 1432 1433 // Remove everything enclosed by the ignore tags from $text. 1434 filter_save_ignore_tags($text, $filterignoretagsopen, $filterignoretagsclose, $ignoretags); 1435 1436 // Remove tags from $text. 1437 filter_save_tags($text, $tags); 1438 1439 // Prepare the limit for preg_match calls. 1440 if (!empty($CFG->filtermatchonepertext) || !empty($CFG->filtermatchoneperpage)) { 1441 $pregreplacelimit = 1; 1442 } else { 1443 $pregreplacelimit = -1; // No limit. 1444 } 1445 1446 // Time to cycle through each phrase to be linked. 1447 foreach ($linkarray as $key => $linkobject) { 1448 if ($linkobject->workregexp === null) { 1449 // This is the case if, when preparing the phrases for filtering, 1450 // we decided that this was not a suitable phrase to match. 1451 continue; 1452 } 1453 1454 // If $CFG->filtermatchoneperpage, avoid previously matched linked phrases. 1455 if (!empty($CFG->filtermatchoneperpage) && isset($usedphrases[$linkobject->workregexp])) { 1456 continue; 1457 } 1458 1459 // Do our highlighting. 1460 $resulttext = preg_replace_callback($linkobject->workregexp, 1461 function ($matches) use ($linkobject) { 1462 if ($linkobject->workreplacementphrase === null) { 1463 filter_prepare_phrase_for_replacement($linkobject); 1464 } 1465 1466 return str_replace('$1', $matches[1], $linkobject->workreplacementphrase); 1467 }, $text, $pregreplacelimit); 1468 1469 // If the text has changed we have to look for links again. 1470 if ($resulttext != $text) { 1471 $text = $resulttext; 1472 // Remove everything enclosed by the ignore tags from $text. 1473 filter_save_ignore_tags($text, $filterignoretagsopen, $filterignoretagsclose, $ignoretags); 1474 // Remove tags from $text. 1475 filter_save_tags($text, $tags); 1476 // If $CFG->filtermatchoneperpage, save linked phrases to request. 1477 if (!empty($CFG->filtermatchoneperpage)) { 1478 $usedphrases[$linkobject->workregexp] = 1; 1479 } 1480 } 1481 } 1482 1483 // Rebuild the text with all the excluded areas. 1484 if (!empty($tags)) { 1485 $text = str_replace(array_keys($tags), $tags, $text); 1486 } 1487 1488 if (!empty($ignoretags)) { 1489 $ignoretags = array_reverse($ignoretags); // Reversed so "progressive" str_replace() will solve some nesting problems. 1490 $text = str_replace(array_keys($ignoretags), $ignoretags, $text); 1491 } 1492 1493 // Remove the protective doubleups. 1494 $text = preg_replace('/([#*%])(\1)/', '\1', $text); 1495 1496 // Add missing javascript for popus. 1497 $text = filter_add_javascript($text); 1498 1499 return $text; 1500 } 1501 1502 /** 1503 * Prepare a list of link for processing with {@link filter_phrases()}. 1504 * 1505 * @param filterobject[] $linkarray the links that will be passed to filter_phrases(). 1506 * @return filterobject[] the updated list of links with necessary pre-processing done. 1507 */ 1508 function filter_prepare_phrases_for_filtering(array $linkarray) { 1509 // Time to cycle through each phrase to be linked. 1510 foreach ($linkarray as $linkobject) { 1511 1512 // Set some defaults if certain properties are missing. 1513 // Properties may be missing if the filterobject class has not been used to construct the object. 1514 if (empty($linkobject->phrase)) { 1515 continue; 1516 } 1517 1518 // Avoid integers < 1000 to be linked. See bug 1446. 1519 $intcurrent = intval($linkobject->phrase); 1520 if (!empty($intcurrent) && strval($intcurrent) == $linkobject->phrase && $intcurrent < 1000) { 1521 continue; 1522 } 1523 1524 // Strip tags out of the phrase. 1525 $linkobject->workregexp = strip_tags($linkobject->phrase); 1526 1527 if (!$linkobject->casesensitive) { 1528 $linkobject->workregexp = core_text::strtolower($linkobject->workregexp); 1529 } 1530 1531 // Double up chars that might cause a false match -- the duplicates will 1532 // be cleared up before returning to the user. 1533 $linkobject->workregexp = preg_replace('/([#*%])/', '\1\1', $linkobject->workregexp); 1534 1535 // Quote any regular expression characters and the delimiter in the work phrase to be searched. 1536 $linkobject->workregexp = preg_quote($linkobject->workregexp, '/'); 1537 1538 // If we ony want to match entire words then add \b assertions. However, only 1539 // do this if the first or last thing in the phrase to match is a word character. 1540 if ($linkobject->fullmatch) { 1541 if (preg_match('~^\w~', $linkobject->workregexp)) { 1542 $linkobject->workregexp = '\b' . $linkobject->workregexp; 1543 } 1544 if (preg_match('~\w$~', $linkobject->workregexp)) { 1545 $linkobject->workregexp = $linkobject->workregexp . '\b'; 1546 } 1547 } 1548 1549 $linkobject->workregexp = '/(' . $linkobject->workregexp . ')/s'; 1550 1551 if (!$linkobject->casesensitive) { 1552 $linkobject->workregexp .= 'iu'; 1553 } 1554 } 1555 1556 return $linkarray; 1557 } 1558 1559 /** 1560 * Fill in the remaining ->work... fields, that would be needed to replace the phrase. 1561 * 1562 * @param filterobject $linkobject the link object on which to set additional fields. 1563 */ 1564 function filter_prepare_phrase_for_replacement(filterobject $linkobject) { 1565 if ($linkobject->replacementcallback !== null) { 1566 list($linkobject->hreftagbegin, $linkobject->hreftagend, $linkobject->replacementphrase) = 1567 call_user_func_array($linkobject->replacementcallback, $linkobject->replacementcallbackdata); 1568 } 1569 1570 if (!isset($linkobject->hreftagbegin) or !isset($linkobject->hreftagend)) { 1571 $linkobject->hreftagbegin = '<span class="highlight"'; 1572 $linkobject->hreftagend = '</span>'; 1573 } 1574 1575 // Double up chars to protect true duplicates 1576 // be cleared up before returning to the user. 1577 $hreftagbeginmangled = preg_replace('/([#*%])/', '\1\1', $linkobject->hreftagbegin); 1578 1579 // Set the replacement phrase properly. 1580 if ($linkobject->replacementphrase) { // We have specified a replacement phrase. 1581 $linkobject->workreplacementphrase = strip_tags($linkobject->replacementphrase); 1582 } else { // The replacement is the original phrase as matched below. 1583 $linkobject->workreplacementphrase = '$1'; 1584 } 1585 1586 $linkobject->workreplacementphrase = $hreftagbeginmangled . 1587 $linkobject->workreplacementphrase . $linkobject->hreftagend; 1588 } 1589 1590 /** 1591 * Remove duplicate from a list of {@link filterobject}. 1592 * 1593 * @param filterobject[] $linkarray a list of filterobject. 1594 * @return filterobject[] the same list, but with dupicates removed. 1595 */ 1596 function filter_remove_duplicates($linkarray) { 1597 1598 $concepts = array(); // Keep a record of concepts as we cycle through. 1599 $lconcepts = array(); // A lower case version for case insensitive. 1600 1601 $cleanlinks = array(); 1602 1603 foreach ($linkarray as $key => $filterobject) { 1604 if ($filterobject->casesensitive) { 1605 $exists = in_array($filterobject->phrase, $concepts); 1606 } else { 1607 $exists = in_array(core_text::strtolower($filterobject->phrase), $lconcepts); 1608 } 1609 1610 if (!$exists) { 1611 $cleanlinks[] = $filterobject; 1612 $concepts[] = $filterobject->phrase; 1613 $lconcepts[] = core_text::strtolower($filterobject->phrase); 1614 } 1615 } 1616 1617 return $cleanlinks; 1618 } 1619 1620 /** 1621 * Extract open/lose tags and their contents to avoid being processed by filters. 1622 * Useful to extract pieces of code like <a>...</a> tags. It returns the text 1623 * converted with some <#xTEXTFILTER_EXCL_SEPARATORx#> codes replacing the extracted text. Such extracted 1624 * texts are returned in the ignoretags array (as values), with codes as keys. 1625 * 1626 * @param string $text the text that we are filtering (in/out) 1627 * @param array $filterignoretagsopen an array of open tags to start searching 1628 * @param array $filterignoretagsclose an array of close tags to end searching 1629 * @param array $ignoretags an array of saved strings useful to rebuild the original text (in/out) 1630 **/ 1631 function filter_save_ignore_tags(&$text, $filterignoretagsopen, $filterignoretagsclose, &$ignoretags) { 1632 1633 // Remove everything enclosed by the ignore tags from $text. 1634 foreach ($filterignoretagsopen as $ikey => $opentag) { 1635 $closetag = $filterignoretagsclose[$ikey]; 1636 // Form regular expression. 1637 $opentag = str_replace('/', '\/', $opentag); // Delimit forward slashes. 1638 $closetag = str_replace('/', '\/', $closetag); // Delimit forward slashes. 1639 $pregexp = '/'.$opentag.'(.*?)'.$closetag.'/is'; 1640 1641 preg_match_all($pregexp, $text, $listofignores); 1642 foreach (array_unique($listofignores[0]) as $key => $value) { 1643 $prefix = (string) (count($ignoretags) + 1); 1644 $ignoretags['<#'.$prefix.TEXTFILTER_EXCL_SEPARATOR.$key.'#>'] = $value; 1645 } 1646 if (!empty($ignoretags)) { 1647 $text = str_replace($ignoretags, array_keys($ignoretags), $text); 1648 } 1649 } 1650 } 1651 1652 /** 1653 * Extract tags (any text enclosed by < and > to avoid being processed by filters. 1654 * It returns the text converted with some <%xTEXTFILTER_EXCL_SEPARATORx%> codes replacing the extracted text. Such extracted 1655 * texts are returned in the tags array (as values), with codes as keys. 1656 * 1657 * @param string $text the text that we are filtering (in/out) 1658 * @param array $tags an array of saved strings useful to rebuild the original text (in/out) 1659 **/ 1660 function filter_save_tags(&$text, &$tags) { 1661 1662 preg_match_all('/<([^#%*].*?)>/is', $text, $listofnewtags); 1663 foreach (array_unique($listofnewtags[0]) as $ntkey => $value) { 1664 $prefix = (string)(count($tags) + 1); 1665 $tags['<%'.$prefix.TEXTFILTER_EXCL_SEPARATOR.$ntkey.'%>'] = $value; 1666 } 1667 if (!empty($tags)) { 1668 $text = str_replace($tags, array_keys($tags), $text); 1669 } 1670 } 1671 1672 /** 1673 * Add missing openpopup javascript to HTML files. 1674 * 1675 * @param string $text 1676 * @return string 1677 */ 1678 function filter_add_javascript($text) { 1679 global $CFG; 1680 1681 if (stripos($text, '</html>') === false) { 1682 return $text; // This is not a html file. 1683 } 1684 if (strpos($text, 'onclick="return openpopup') === false) { 1685 return $text; // No popup - no need to add javascript. 1686 } 1687 $js = " 1688 <script type=\"text/javascript\"> 1689 <!-- 1690 function openpopup(url,name,options,fullscreen) { 1691 fullurl = \"".$CFG->wwwroot."\" + url; 1692 windowobj = window.open(fullurl,name,options); 1693 if (fullscreen) { 1694 windowobj.moveTo(0,0); 1695 windowobj.resizeTo(screen.availWidth,screen.availHeight); 1696 } 1697 windowobj.focus(); 1698 return false; 1699 } 1700 // --> 1701 </script>"; 1702 if (stripos($text, '</head>') !== false) { 1703 // Try to add it into the head element. 1704 $text = str_ireplace('</head>', $js.'</head>', $text); 1705 return $text; 1706 } 1707 1708 // Last chance - try adding head element. 1709 return preg_replace("/<html.*?>/is", "\\0<head>".$js.'</head>', $text); 1710 }
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