The specific method is as follows:
HtmlAttributeFilter.class.php class file is as follows:
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/** HTML Attribute Filter * Date: 2013-09-22 * Author: fdipzone * ver: 1.0 * * Func: * public strip filter attribute * public setAllow Set allowed attributes * public setException Set special case * public setIgnore Set the ignored mark * private findElements Search for elements that need to be processed * private findAttributes Search attributes * private removeAttributes Remove attributes * private isException Determine whether it is a special case * private createAttributes Create attributes * private protect special character escaping */
class HtmlAttributeFilter{ // class start
private $_str = ''; // source string private $_allow = array(); // Allowed retained attributes For example: array('id','class','title') private $_exception = array(); // Special example: array('a'=>array('href','class'),'span'=>array('class')) private $_ignore = array(); // Ignore filtered tags For example: array('span','img')
/**Process HTML, filter attributes that are not retained * @param String $str source string * @return String */ public function strip($str){ $this->_str = $str;
if(is_string($this->_str) && strlen($this->_str)>0){ // Determine the string
$this->_str = strtolower($this->_str); // Convert to lowercase
$res = $this->findElements(); if(is_string($res)){ return $res; } $nodes = $this->findAttributes($res); $this->removeAttributes($nodes); } return $this->_str; }
/**Set allowed attributes * @param Array $param */ public function setAllow($param=array()){ $this->_allow = $param; }
/**Set up special case * @param Array $param */ public function setException($param=array()){ $this->_exception = $param; }
/**Set ignored tags * @param Array $param */ public function setIgnore($param=array()){ $this->_ignore = $param; }
/**Search for elements to be processed*/ 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; } }
/**Search properties * @param Array $nodes elements to be processed */ private function findAttributes($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; }
/**Remove attribute * @param Array $nodes elements to be processed */ private function removeAttributes($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); } }
/**Determine whether it is a special case * @param String $element_name Element name * @param String $attribute_name attribute name * @param Array $exceptions Allowed exceptions * @return boolean */ private function isException($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; }
/**Special character escaping * @param String $str source string * @return String */ private function protect($str){ $conversions = array( "^" => "^", "[" => "[", "." => ".", "$" => "$", "{" => "{", "*" => "*", "(" => "(", "\" => "\\", "/" => "/", "+" => "+", ")" => ")", "|" => "|", "?" => "?", "<" => "<", ">" => ">" ); return strtr($str, $conversions); }
} // class end
?> |
demo示例代码如下：
4 11 12 |
<🎜>require('HtmlAttributeFilter.class.php'); <🎜>
<🎜> <🎜>
<🎜>$str = '';
$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)); ?> |
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