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See Release Notes

  • Bug fixes for general core bugs in 4.2.x will end 22 April 2024 (12 months).
  • Bug fixes for security issues in 4.2.x will end 7 October 2024 (18 months).
  • PHP version: minimum PHP 8.0.0 Note: minimum PHP version has increased since Moodle 4.1. PHP 8.1.x is supported too.
<?php

/**
 * Abstract class for a set of proprietary modules that clean up (tidy)
 * poorly written HTML.
 * @todo Figure out how to protect some of these methods/properties
 */
class HTMLPurifier_HTMLModule_Tidy extends HTMLPurifier_HTMLModule
{
    /**
     * List of supported levels.
     * Index zero is a special case "no fixes" level.
     * @type array
     */
    public $levels = array(0 => 'none', 'light', 'medium', 'heavy');

    /**
     * Default level to place all fixes in.
     * Disabled by default.
     * @type string
     */
    public $defaultLevel = null;

    /**
     * Lists of fixes used by getFixesForLevel().
     * Format is:
     *      HTMLModule_Tidy->fixesForLevel[$level] = array('fix-1', 'fix-2');
     * @type array
     */
    public $fixesForLevel = array(
        'light' => array(),
        'medium' => array(),
        'heavy' => array()
    );

    /**
     * Lazy load constructs the module by determining the necessary
     * fixes to create and then delegating to the populate() function.
     * @param HTMLPurifier_Config $config
     * @todo Wildcard matching and error reporting when an added or
     *       subtracted fix has no effect.
     */
    public function setup($config)
    {
        // create fixes, initialize fixesForLevel
        $fixes = $this->makeFixes();
        $this->makeFixesForLevel($fixes);

        // figure out which fixes to use
        $level = $config->get('HTML.TidyLevel');
        $fixes_lookup = $this->getFixesForLevel($level);

        // get custom fix declarations: these need namespace processing
        $add_fixes = $config->get('HTML.TidyAdd');
        $remove_fixes = $config->get('HTML.TidyRemove');

        foreach ($fixes as $name => $fix) {
            // needs to be refactored a little to implement globbing
            if (isset($remove_fixes[$name]) ||
                (!isset($add_fixes[$name]) && !isset($fixes_lookup[$name]))) {
                unset($fixes[$name]);
            }
        }

        // populate this module with necessary fixes
        $this->populate($fixes);
    }

    /**
     * Retrieves all fixes per a level, returning fixes for that specific
     * level as well as all levels below it.
     * @param string $level level identifier, see $levels for valid values
     * @return array Lookup up table of fixes
     */
    public function getFixesForLevel($level)
    {
        if ($level == $this->levels[0]) {
            return array();
        }
        $activated_levels = array();
        for ($i = 1, $c = count($this->levels); $i < $c; $i++) {
            $activated_levels[] = $this->levels[$i];
            if ($this->levels[$i] == $level) {
                break;
            }
        }
        if ($i == $c) {
            trigger_error(
                'Tidy level ' . htmlspecialchars($level) . ' not recognized',
                E_USER_WARNING
            );
            return array();
        }
        $ret = array();
        foreach ($activated_levels as $level) {
            foreach ($this->fixesForLevel[$level] as $fix) {
                $ret[$fix] = true;
            }
        }
        return $ret;
    }

    /**
     * Dynamically populates the $fixesForLevel member variable using
     * the fixes array. It may be custom overloaded, used in conjunction
     * with $defaultLevel, or not used at all.
     * @param array $fixes
     */
    public function makeFixesForLevel($fixes)
    {
        if (!isset($this->defaultLevel)) {
            return;
        }
        if (!isset($this->fixesForLevel[$this->defaultLevel])) {
            trigger_error(
                'Default level ' . $this->defaultLevel . ' does not exist',
                E_USER_ERROR
            );
            return;
        }
        $this->fixesForLevel[$this->defaultLevel] = array_keys($fixes);
    }

    /**
     * Populates the module with transforms and other special-case code
     * based on a list of fixes passed to it
     * @param array $fixes Lookup table of fixes to activate
     */
    public function populate($fixes)
    {
        foreach ($fixes as $name => $fix) {
            // determine what the fix is for
            list($type, $params) = $this->getFixType($name);
            switch ($type) {
                case 'attr_transform_pre':
                case 'attr_transform_post':
                    $attr = $params['attr'];
                    if (isset($params['element'])) {
                        $element = $params['element'];
                        if (empty($this->info[$element])) {
                            $e = $this->addBlankElement($element);
                        } else {
                            $e = $this->info[$element];
                        }
                    } else {
                        $type = "info_$type";
                        $e = $this;
                    }
< // PHP does some weird parsing when I do < // $e->$type[$attr], so I have to assign a ref. < $f =& $e->$type; < $f[$attr] = $fix;
> $e->{$type}[$attr] = $fix;
break; case 'tag_transform': $this->info_tag_transform[$params['element']] = $fix; break; case 'child': case 'content_model_type': $element = $params['element']; if (empty($this->info[$element])) { $e = $this->addBlankElement($element); } else { $e = $this->info[$element]; } $e->$type = $fix; break; default: trigger_error("Fix type $type not supported", E_USER_ERROR); break; } } } /** * Parses a fix name and determines what kind of fix it is, as well * as other information defined by the fix * @param $name String name of fix * @return array(string $fix_type, array $fix_parameters) * @note $fix_parameters is type dependant, see populate() for usage * of these parameters */ public function getFixType($name) { // parse it $property = $attr = null; if (strpos($name, '#') !== false) { list($name, $property) = explode('#', $name); } if (strpos($name, '@') !== false) { list($name, $attr) = explode('@', $name); } // figure out the parameters $params = array(); if ($name !== '') { $params['element'] = $name; } if (!is_null($attr)) { $params['attr'] = $attr; } // special case: attribute transform if (!is_null($attr)) { if (is_null($property)) { $property = 'pre'; } $type = 'attr_transform_' . $property; return array($type, $params); } // special case: tag transform if (is_null($property)) { return array('tag_transform', $params); } return array($property, $params); } /** * Defines all fixes the module will perform in a compact * associative array of fix name to fix implementation. * @return array */ public function makeFixes() { } } // vim: et sw=4 sts=4