具體方法如下：
HtmlAttributeFilter.class.php類文件如下：
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 <?php /** HTML Attribute Filter * Date: 2013-09-22 * Author: fdipzone * ver: 1.0 * * Func: * public strip 過濾屬性 * public setAllow 設置允許的屬性 * public setException 設置特例 * public setIgnore 設置忽略的標記 * private findElements 搜尋需要處理的元素 * private findAttributes 搜尋屬性 * private removeAttributes 移除屬性 * private isException 判斷是否特例 * private createAttributes 創建屬性 * private protect 特殊字符轉義 */ class HtmlAttributeFilter{ // class start private $_str = ''; // 源字符串 private $_allow = array(); // 允許保留的屬性 例如:array('id','class','title') private $_exception = array(); // 特例 例如:array('a'=>array('href','class'),'span'=>array('class')) private $_ignore = array(); // 忽略過濾的標記 例如:array('span','img') /** 處理HTML,過濾不保留的屬性 * @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){ // 判斷字符串 $this->_str = strtolower($this->_str); // 轉成小寫 $res = $this->findElements(); if(is_string($res)){ return $res; } $nodes = $this->findAttributes($res); $this->removeAttributes($nodes); } return $this->_str; } /** 設置允許的屬性 * @param Array $param */ public function setAllow($param=array()){ $this->_allow = $param; } /** 設置特例 * @param Array $param */ public function setException($param=array()){ $this->_exception = $param; } /** 設置忽略的標記 * @param Array $param */ public function setIgnore($param=array()){ $this->_ignore = $param; } /** 搜尋需要處理的元素 */ 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; } } /** 搜尋屬性 * @param Array $nodes 需要處理的元素 */ private function findAttributes($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; } /** 移除屬性 * @param Array $nodes 需要處理的元素 */ private function removeAttributes($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); } } /** 判斷是否特例 * @param String $element_name 元素名 * @param String $attribute_name 屬性名 * @param Array $exceptions 允許的特例 * @return boolean */ private function isException($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; } /** 創建屬性 * @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; } /** 特殊字符轉義 * @param String $str 源字符串 * @return String */ private function protect($str){ $conversions = array( "^" => "^", "[" => "[", "." => ".", "$" => "$", "{" => "{", "*" => "*", "(" => "(", "" => "", "/" => "/", "+" => "+", ")" => ")", "|" => "|", "?" => "?", "<" => "<", ">" => ">" ); return strtr($str, $conversions); } } // class end ?>demo示例代碼如下：
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 <?php require('HtmlAttributeFilter.class.php'); $str = '<div class="bd clearfix" id="index_hilite_ul"><ul class="list"><li><img src="http://su.bdimg.com/static/skin/img/logo_white.png" width="118" height="148"><div class="cover"><a class="text" href="http://www.jb51.net"><strong>yuna</strong><p>love</p></a><strong class="t g">want to know</strong><a href="/login.html" class="ppBtn"><strong class="text">YES</strong></a></div></li></ul></div>'; $obj = new HtmlAttributeFilter(); // 允許id屬性 $obj->setAllow(array('id')); $obj->setException(array( 'a' => array('href'), // a 標簽允許有 href屬性特例 'ul' => array('class') // ul 標簽允許有 class屬性特例 )); // img 標簽忽略,不過濾任何屬性 $obj->setIgnore(array('img')); echo 'source str:<br>'; echo htmlspecialchars($str).'<br><br>'; echo 'filter str:<br>'; echo htmlspecialchars($obj->strip($str)); ?>
