php XML file parsing class (with demo code)

/**XML file analysis class
* Date: 2013-02-01
* Author: fdipzone
* Ver: 1.0
* Edition bbs.it-home.org
* func:
* loadXmlFile($xmlfile) reads xml file and outputs Array
* loadXmlString($xmlstring) reads xmlstring and outputs Array
*/

class XMLParser{
    /**Read xml file
 * @param String $xmlfile
 * @return Array
*/
    public function loadXmlFile($xmlfile){
        // get xmlfile content
        $xmlstring = file_exists($xmlfile)? file_get_contents($xmlfile) : '';

        // parser xml
        list($flag, $data) = $this->parser($xmlstring);
        return $this->response($flag, $data);
    }


    /**读取xmlstring
    * @param  String $xmlstring
    * @return Array
*/
    public function loadXmlString($xmlstring){
        // parser xml
        list($flag, $data) = $this->parser($xmlstring);

        return $this->response($flag, $data);
    }

    /**Interpret xml content
 * @param String $xmlstring
 * @return Array
*/
    private function parser($xmlstring){
        $flag = false;
        $data = array();

        // check xml format
        if($this->checkXmlFormat($xmlstring)){
            $flag = true;

            // xml to object
            $data = simpleXML_load_string($xmlstring, 'SimpleXMLElement', LIBXML_NOCDATA);

            // object to array
            $this->objectToArray($data);
        }
        return array($flag, $data);
    }

    /**Check whether the xml format is correct
 * @param String $xmlstring
 * @return boolean
*/
    private function checkXmlFormat($xmlstring){
        if($xmlstring==''){
            return false;
        }

        $xml_parser_obj = xml_parser_create();

        if(xml_parse_into_struct($xml_parser_obj, $xmlstring, $vals, $indexs)===1){ // 1:success 0:fail
            return true;
        }else{
            return false;
        }
    }
    /**object 转 Array
    * @param  object $object
    * @return Array
*/
    private function objectToArray(&$object){
        $object = (array)$object;
        foreach($object as $key => $value){
            if($value==''){
                $object[$key] = "";
            }else{
                if(is_object($value) || is_array($value)){
                    $this->objectToArray($value);
                    $object[$key] = $value;
                }
            }
        }
    }
    /**Output returns
 * @param boolean $flag true:false
 * @param Array $data converted data
 * @return Array
*/
    private function response($flag=false, $data=array()){
        return array($flag, $data);
    }
}
?>

2，演示示例

require "XMLParser.class.php";

$xmlfile = 'file.xml';
$xmlstring = '

1000

100
fdipzone
1
28

';

echo '';  </li>
<li>  </li>
<li>$xml_parser = new XMLParser();  </li>
<li>echo "response xmlfilern";  </li>
<li>list($flag, $xmldata) = $xml_parser->loadXmlFile($xmlfile);  </li>
<li>if($flag){  </li>
<li>    print_r($xmldata);  </li>
<li>}  </li>
<li>  </li>
<li>echo "response xmlstringrn";  </li>
<li>list($flag, $xmldata) = $xml_parser->loadXmlString($xmlstring);  </li>
<li>if($flag){  </li>
<li>    print_r($xmldata);  </li>
<li>}  </li>
<li>  </li>
<li>echo '';
?>

附，PHP XML预定义常量: http://bbs.it-home.org/shouce/php5/libxml.constants.html