php过滤html的标签的属性

版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/qq_29058883/article/details/86484488

/** 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

小程序图文详情的细节

$content=str_replace('section','div',$content);

$content = htmlentities($content);

$content = html_entity_decode($content);

$content = str_replace('"','"',$content);