<?php
/**
* Zend Framework
*
* LICENSE
*
* This source file is subject to the new BSD license that is bundled
* with this package in the file LICENSE.txt.
* It is also available through the world-wide-web at this URL:
* http://framework.zend.com/license/new-bsd
* If you did not receive a copy of the license and are unable to
* obtain it through the world-wide-web, please send an email
* to license@zend.com so we can send you a copy immediately.
*
* @category Zend
* @package Zend_Filter
* @copyright Copyright (c) 2005-2012 Zend Technologies USA Inc. (http://www.zend.com)
* @license http://framework.zend.com/license/new-bsd New BSD License
* @version $Id: StripTags.php 24594 2012-01-05 21:27:01Z matthew $
*/
/**
* @see Zend_Filter_Interface
*/
require_once 'Zend/Filter/Interface.php';
/**
* @category Zend
* @package Zend_Filter
* @copyright Copyright (c) 2005-2012 Zend Technologies USA Inc. (http://www.zend.com)
* @license http://framework.zend.com/license/new-bsd New BSD License
*/
class Zend_Filter_StripTags implements Zend_Filter_Interface
{
/**
* Unique ID prefix used for allowing comments
*/
const UNIQUE_ID_PREFIX = '__Zend_Filter_StripTags__';
/**
* Whether comments are allowed
*
* If false (the default), then comments are removed from the input string.
*
* This setting is now deprecated, and ignored internally.
*
* @deprecated
* @var boolean
*/
public $commentsAllowed = false;
/**
* Array of allowed tags and allowed attributes for each allowed tag
*
* Tags are stored in the array keys, and the array values are themselves
* arrays of the attributes allowed for the corresponding tag.
*
* @var array
*/
protected $_tagsAllowed = array();
/**
* Array of allowed attributes for all allowed tags
*
* Attributes stored here are allowed for all of the allowed tags.
*
* @var array
*/
protected $_attributesAllowed = array();
/**
* Sets the filter options
* Allowed options are
* 'allowTags' => Tags which are allowed
* 'allowAttribs' => Attributes which are allowed
* 'allowComments' => Are comments allowed ?
*
* @param string|array|Zend_Config $options
* @return void
*/
public function __construct($options = null)
{
if ($options instanceof Zend_Config) {
$options = $options->toArray();
} else if ((!is_array($options)) || (is_array($options) && !array_key_exists('allowTags', $options) &&
!array_key_exists('allowAttribs', $options) && !array_key_exists('allowComments', $options))) {
$options = func_get_args();
$temp['allowTags'] = array_shift($options);
if (!empty($options)) {
$temp['allowAttribs'] = array_shift($options);
}
if (!empty($options)) {
$temp['allowComments'] = array_shift($options);
}
$options = $temp;
}
if (array_key_exists('allowTags', $options)) {
$this->setTagsAllowed($options['allowTags']);
}
if (array_key_exists('allowAttribs', $options)) {
$this->setAttributesAllowed($options['allowAttribs']);
}
if (array_key_exists('allowComments', $options)) {
$this->setCommentsAllowed($options['allowComments']);
}
}
/**
* Returns the commentsAllowed option
*
* This setting is now deprecated and ignored internally.
*
* @deprecated
* @return bool
*/
public function getCommentsAllowed()
{
return $this->commentsAllowed;
}
/**
* Sets the commentsAllowed option
*
* This setting is now deprecated and ignored internally.
*
* @deprecated
* @param boolean $commentsAllowed
* @return Zend_Filter_StripTags Provides a fluent interface
*/
public function setCommentsAllowed($commentsAllowed)
{
$this->commentsAllowed = (boolean) $commentsAllowed;
return $this;
}
/**
* Returns the tagsAllowed option
*
* @return array
*/
public function getTagsAllowed()
{
return $this->_tagsAllowed;
}
/**
* Sets the tagsAllowed option
*
* @param array|string $tagsAllowed
* @return Zend_Filter_StripTags Provides a fluent interface
*/
public function setTagsAllowed($tagsAllowed)
{
if (!is_array($tagsAllowed)) {
$tagsAllowed = array($tagsAllowed);
}
foreach ($tagsAllowed as $index => $element) {
// If the tag was provided without attributes
if (is_int($index) && is_string($element)) {
// Canonicalize the tag name
$tagName = strtolower($element);
// Store the tag as allowed with no attributes
$this->_tagsAllowed[$tagName] = array();
}
// Otherwise, if a tag was provided with attributes
else if (is_string($index) && (is_array($element) || is_string($element))) {
// Canonicalize the tag name
$tagName = strtolower($index);
// Canonicalize the attributes
if (is_string($element)) {
$element = array($element);
}
// Store the tag as allowed with the provided attributes
$this->_tagsAllowed[$tagName] = array();
foreach ($element as $attribute) {
if (is_string($attribute)) {
// Canonicalize the attribute name
$attributeName = strtolower($attribute);
$this->_tagsAllowed[$tagName][$attributeName] = null;
}
}
}
}
return $this;
}
/**
* Returns the attributesAllowed option
*
* @return array
*/
public function getAttributesAllowed()
{
return $this->_attributesAllowed;
}
/**
* Sets the attributesAllowed option
*
* @param array|string $attributesAllowed
* @return Zend_Filter_StripTags Provides a fluent interface
*/
public function setAttributesAllowed($attributesAllowed)
{
if (!is_array($attributesAllowed)) {
$attributesAllowed = array($attributesAllowed);
}
// Store each attribute as allowed
foreach ($attributesAllowed as $attribute) {
if (is_string($attribute)) {
// Canonicalize the attribute name
$attributeName = strtolower($attribute);
$this->_attributesAllowed[$attributeName] = null;
}
}
return $this;
}
/**
* Defined by Zend_Filter_Interface
*
* @todo improve docblock descriptions
*
* @param string $value
* @return string
*/
public function filter($value)
{
$value = (string) $value;
// Strip HTML comments first
while (strpos($value, '<!--') !== false) {
$pos = strrpos($value, '<!--');
$start = substr($value, 0, $pos);
$value = substr($value, $pos);
// If there is no comment closing tag, strip whole text
if (!preg_match('/--\s*>/s', $value)) {
$value = '';
} else {
$value = preg_replace('/<(?:!(?:--[\s\S]*?--\s*)?(>))/s', '', $value);
}
$value = $start . $value;
}
// Initialize accumulator for filtered data
$dataFiltered = '';
// Parse the input data iteratively as regular pre-tag text followed by a
// tag; either may be empty strings
preg_match_all('/([^<]*)(<?[^>]*>?)/', (string) $value, $matches);
// Iterate over each set of matches
foreach ($matches[1] as $index => $preTag) {
// If the pre-tag text is non-empty, strip any ">" characters from it
if (strlen($preTag)) {
$preTag = str_replace('>', '', $preTag);
}
// If a tag exists in this match, then filter the tag
$tag = $matches[2][$index];
if (strlen($tag)) {
$tagFiltered = $this->_filterTag($tag);
} else {
$tagFiltered = '';
}
// Add the filtered pre-tag text and filtered tag to the data buffer
$dataFiltered .= $preTag . $tagFiltered;
}
// Return the filtered data
return $dataFiltered;
}
/**
* Filters a single tag against the current option settings
*
* @param string $tag
* @return string
*/
protected function _filterTag($tag)
{
// Parse the tag into:
// 1. a starting delimiter (mandatory)
// 2. a tag name (if available)
// 3. a string of attributes (if available)
// 4. an ending delimiter (if available)
$isMatch = preg_match('~(</?)(\w*)((/(?!>)|[^/>])*)(/?>)~', $tag, $matches);
// If the tag does not match, then strip the tag entirely
if (!$isMatch) {
return '';
}
// Save the matches to more meaningfully named variables
$tagStart = $matches[1];
$tagName = strtolower($matches[2]);
$tagAttributes = $matches[3];
$tagEnd = $matches[5];
// If the tag is not an allowed tag, then remove the tag entirely
if (!isset($this->_tagsAllowed[$tagName])) {
return '';
}
// Trim the attribute string of whitespace at the ends
$tagAttributes = trim($tagAttributes);
// If there are non-whitespace characters in the attribute string
if (strlen($tagAttributes)) {
// Parse iteratively for well-formed attributes
preg_match_all('/([\w-]+)\s*=\s*(?:(")(.*?)"|(\')(.*?)\')/s', $tagAttributes, $matches);
// Initialize valid attribute accumulator
$tagAttributes = '';
// Iterate over each matched attribute
foreach ($matches[1] as $index => $attributeName) {
$attributeName = strtolower($attributeName);
$attributeDelimiter = empty($matches[2][$index]) ? $matches[4][$index] : $matches[2][$index];
$attributeValue = empty($matches[3][$index]) ? $matches[5][$index] : $matches[3][$index];
// If the attribute is not allowed, then remove it entirely
if (!array_key_exists($attributeName, $this->_tagsAllowed[$tagName])
&& !array_key_exists($attributeName, $this->_attributesAllowed)) {
continue;
}
// Add the attribute to the accumulator
$tagAttributes .= " $attributeName=" . $attributeDelimiter
. $attributeValue . $attributeDelimiter;
}
}
// Reconstruct tags ending with "/>" as backwards-compatible XHTML tag
if (strpos($tagEnd, '/') !== false) {
$tagEnd = " $tagEnd";
}
// Return the filtered tag
return $tagStart . $tagName . $tagAttributes . $tagEnd;
}
}