php 过滤html标记属性类(附源码)

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发布： 2016-07-25 08:55:20

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/** HTML Attribute Filter
* Date: 2013-09-22
* Author: fdipzone
* ver: 1.0
* edit: bbs.it-home.org
* Func:
* public strip 过滤属性
* public setAllow 设置允许的属性
* public setException 设置特例
* public setIgnore 设置忽略的标记
* private findElements 搜寻需要处理的元素
* private findAttributes 搜寻属性
* private removeAttributes 移除属性
* private isException 判断是否特例
* private createAttributes 创建属性
* private protect 特殊字符转义
*/
class HtmlAttributeFilter{ // class start
private $_str = ''; // 源字符串
private $_allow = array(); // 允许保留的属性例如:array('id','class','title')
private $_exception = array(); // 特例例如:array('a'=>array('href','class'),'span'=>array('class'))
private $_ignore = array(); // 忽略过滤的标记例如:array('span','img')
/** 处理HTML,过滤不保留的属性
* @param String $str 源字符串
* @return String
*/
public function strip($str){
$this->_str = $str;
if(is_string($this->_str) && strlen($this->_str)>0){ // 判断字符串
$this->_str = strtolower($this->_str); // 转成小写
$res = $this->findElements();
if(is_string($res)){
return $res;
}
$nodes = $this->findAttributes($res);
$this->removeAttributes($nodes);
}
return $this->_str;
}
/** 设置允许的属性
* @param Array $param
*/
public function setAllow($param=array()){
$this->_allow = $param;
}
/** 设置特例
* @param Array $param
*/
public function setException($param=array()){
$this->_exception = $param;
}
/** 设置忽略的标记
* @param Array $param
*/
public function setIgnore($param=array()){
$this->_ignore = $param;
}
/** 搜寻需要处理的元素 */
private function findElements(){
$nodes = array();
preg_match_all("/\n]+)([^>]*)>/i", $this->_str, $elements);
foreach($elements[1] as $el_key => $element){
if($elements[2][$el_key]){
$literal = $elements[0][$el_key];
$element_name = $elements[1][$el_key];
$attributes = $elements[2][$el_key];
if(is_array($this->_ignore) && !in_array($element_name, $this->_ignore)){
$nodes[] = array('literal'=>$literal, 'name'=>$element_name, 'attributes'=>$attributes);
}
}
}
if(!$nodes[0]){
return $this->_str;
}else{
return $nodes;
}
}
/** 搜寻属性
* @param Array $nodes 需要处理的元素
*/
private function findAttributes($nodes){
foreach($nodes as &$node){
preg_match_all("/([^ =]+)\s*=\s*[\"|']{0,1}([^\"']*)[\"|']{0,1}/i", $node['attributes'], $attributes);
if($attributes[1]){
foreach($attributes[1] as $att_key=>$att){
$literal = $attributes[0][$att_key];
$attribute_name = $attributes[1][$att_key];
$value = $attributes[2][$att_key];
$atts[] = array('literal'=>$literal, 'name'=>$attribute_name, 'value'=>$value);
}
}else{
$node['attributes'] = null;
}
$node['attributes'] = $atts;
unset($atts);
}
return $nodes;
}
/** 移除属性
* @param Array $nodes 需要处理的元素
*/
private function removeAttributes($nodes){
foreach($nodes as $node){
$node_name = $node['name'];
$new_attributes = '';
if(is_array($node['attributes'])){
foreach($node['attributes'] as $attribute){
if((is_array($this->_allow) && in_array($attribute['name'], $this->_allow)) || $this->isException($node_name, $attribute['name'], $this->_exception)){
$new_attributes = $this->createAttributes($new_attributes, $attribute['name'], $attribute['value']);
}
}
}
$replacement = ($new_attributes) ? "" : "";
$this->_str = preg_replace('/'.$this->protect($node['literal']).'/', $replacement, $this->_str);
}
}
/** 判断是否特例
* @param String $element_name 元素名
* @param String $attribute_name 属性名
* @param Array $exceptions 允许的特例
* @return boolean
*/
private function isException($element_name, $attribute_name, $exceptions){
if(array_key_exists($element_name, $this->_exception)){
if(in_array($attribute_name, $this->_exception[$element_name])){
return true;
}
}
return false;
}
/** 创建属性
* @param String $new_attributes
* @param String $name
* @param String $value
* @return String
*/
private function createAttributes($new_attributes, $name, $value){
if($new_attributes){
$new_attributes .= " ";
}
$new_attributes .= "$name=\"$value\"";
return $new_attributes;
}
/** 特殊字符转义
* @param String $str 源字符串
* @return String
*/
private function protect($str){
$conversions = array(
"^" => "\^",
"[" => "\[",
"." => "\.",
"$" => "\$",
"{" => "\{",
"*" => "\*",
"(" => "\(",
"\\" => "\\\\",
"/" => "\/",
"+" => "\+",
")" => "\)",
"|" => "\|",
"?" => "\?",
" "\ ">" => "\>"
);
return strtr($str, $conversions);
}
} // class end
?>