php过滤html标记属性类用法实例

本文实例讲述了php 过滤html标记属性类及其用法。是PHP项目开发中比较常见的实用技巧。分享给大家供大家参考。具体方法如下：

HtmlAttributeFilter.class.php类文件如下：

<?php /** HTML Attribute Filter *  Date:  2013-09-22 *  Author: fdipzone *  ver:  1.0 * *  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  ?>