friendica_2021-01/library/HTMLPurifier/ChildDef/Custom.php

90 lines
2.7 KiB
PHP
Executable file

<?php
/**
* Custom validation class, accepts DTD child definitions
*
* @warning Currently this class is an all or nothing proposition, that is,
* it will only give a bool return value.
*/
class HTMLPurifier_ChildDef_Custom extends HTMLPurifier_ChildDef
{
public $type = 'custom';
public $allow_empty = false;
/**
* Allowed child pattern as defined by the DTD
*/
public $dtd_regex;
/**
* PCRE regex derived from $dtd_regex
* @private
*/
private $_pcre_regex;
/**
* @param $dtd_regex Allowed child pattern from the DTD
*/
public function __construct($dtd_regex) {
$this->dtd_regex = $dtd_regex;
$this->_compileRegex();
}
/**
* Compiles the PCRE regex from a DTD regex ($dtd_regex to $_pcre_regex)
*/
protected function _compileRegex() {
$raw = str_replace(' ', '', $this->dtd_regex);
if ($raw{0} != '(') {
$raw = "($raw)";
}
$el = '[#a-zA-Z0-9_.-]+';
$reg = $raw;
// COMPLICATED! AND MIGHT BE BUGGY! I HAVE NO CLUE WHAT I'M
// DOING! Seriously: if there's problems, please report them.
// collect all elements into the $elements array
preg_match_all("/$el/", $reg, $matches);
foreach ($matches[0] as $match) {
$this->elements[$match] = true;
}
// setup all elements as parentheticals with leading commas
$reg = preg_replace("/$el/", '(,\\0)', $reg);
// remove commas when they were not solicited
$reg = preg_replace("/([^,(|]\(+),/", '\\1', $reg);
// remove all non-paranthetical commas: they are handled by first regex
$reg = preg_replace("/,\(/", '(', $reg);
$this->_pcre_regex = $reg;
}
public function validateChildren($tokens_of_children, $config, $context) {
$list_of_children = '';
$nesting = 0; // depth into the nest
foreach ($tokens_of_children as $token) {
if (!empty($token->is_whitespace)) continue;
$is_child = ($nesting == 0); // direct
if ($token instanceof HTMLPurifier_Token_Start) {
$nesting++;
} elseif ($token instanceof HTMLPurifier_Token_End) {
$nesting--;
}
if ($is_child) {
$list_of_children .= $token->name . ',';
}
}
// add leading comma to deal with stray comma declarations
$list_of_children = ',' . rtrim($list_of_children, ',');
$okay =
preg_match(
'/^,?'.$this->_pcre_regex.'$/',
$list_of_children
);
return (bool) $okay;
}
}
// vim: et sw=4 sts=4