/** 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) ? "<$node_name $new_attributes>" : "<$node_name>";  
 -             $this->_str = preg_replace('/'.$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  
 -   
 - ?>
 
 2,演示示例
  - require('HtmlAttributeFilter.class.php');  
 -   
 - $str = '
 yunalove want to knowYES ';   -   
 - $obj = new HtmlAttributeFilter();  
 -   
 - // 允许id属性  
 - $obj->setAllow(array('id'));  
 -   
 - $obj->setException(array(  
 -                     'a' => array('href'),   // a 标签允许有 href属性特例  
 -                     'ul' => array('class')  // ul 标签允许有 class属性特例  
 - ));  
 -   
 - // img 标签忽略,不过滤任何属性  
 - $obj->setIgnore(array('img'));  
 -   
 - echo 'source str:
 ';   - echo htmlspecialchars($str).'
  ';   - echo 'filter str:
 ';   - echo htmlspecialchars($obj->strip($str));  
 - ?>
 
 附,php 过滤html标记属性类的源码下载地址  |