今天看到一个很好的类-操作xml的！

              for reporting this bug.
        - .91 No Longer requires PHP4!
        - .91 now all elements are array.  Using objects has
          been discontinued.
*/
class xml_container{
    function store($k,$v) {
        $this->{$k}[] = $v;
    }
}
/* parses the information */
/*********************************
*    类定义开始
*
*********************************/
class xml{
   
    // initialize some variables
    var $current_tag=array();
    var $xml_parser;
    var $Version = 1.0;
    var $tagtracker = array();
    /* Here are the
[url=javascript:;]XML[/url]
functions needed by expat */
    /* when expat hits an opening tag, it fires up this function */
    function startElement($parser, $name, $attrs){
        array_push($this->current_tag, $name); // add tag to the cur. tag array
        $curtag = implode("_",$this->current_tag); // piece together tag
        /* this tracks what array index we are on for this tag */
        if(isset($this->tagtracker["$curtag"])) {
            $this->tagtracker["$curtag"]++;
        }
        else{
            $this->tagtracker["$curtag"]=0;
        }
        /* if there are attributes for this tag, we set them here. */
        if(count($attrs)>0) {
            $j = $this->tagtracker["$curtag"];
            if(!$j) $j = 0;
            if(!is_object($GLOBALS[$this->identifier]["$curtag"][$j])) {
                $GLOBALS[$this->identifier]["$curtag"][$j] = new xml_container;
            }
            $GLOBALS[$this->identifier]["$curtag"][$j]->store("attributes",$attrs);
        }
   
    }// end function startElement
    /* when expat hits a closing tag, it fires up this function */
    function endElement($parser, $name) {
        $curtag = implode("_",$this->current_tag); // piece together tag
        
        // before we pop it off,
        // so we can get the correct
        // cdata
        if(!$this->tagdata["$curtag"]) {
            $popped = array_pop($this->current_tag); // or else we screw up where we are
            return; // if we have no data for the tag
        }
        else{
            $TD = $this->tagdata["$curtag"];
            unset($this->tagdata["$curtag"]);
        }
        $popped = array_pop($this->current_tag);
        // we want the tag name for
        // the tag above this, it  
        // allows us to group the
        // tags together in a more
        // intuitive way.
        if(sizeof($this->current_tag) == 0) return; // if we aren't in a tag
        $curtag = implode("_",$this->current_tag); // piece together tag
        // this time for the arrays
        $j = $this->tagtracker["$curtag"];
        
        if(!$j) $j = 0;
        if(!is_object($GLOBALS[$this->identifier]["$curtag"][$j])) {
            $GLOBALS[$this->identifier]["$curtag"][$j] = new xml_container;
        }
        $GLOBALS[$this->identifier]["$curtag"][$j]->store($name,$TD);
        #$this->tagdata["$curtag"]);
        unset($TD);
        return TRUE;
    } // end function endElement
    /* when expat finds some internal tag character data,
       it fires up this function */
    function characterData($parser, $cdata) {
        $curtag = implode("_",$this->current_tag); // piece together tag
        $this->tagdata["$curtag"] .= $cdata;
    }
    function xml($data,$identifier='xml') {   
        $this->identifier = $identifier;
        // create parser object
        $this->xml_parser = xml_parser_create();
        // set up some options and handlers
        xml_set_object($this->xml_parser,$this);
        xml_parser_set_option($this->xml_parser,XML_OPTION_CASE_FOLDING,0);
        xml_set_element_handler($this->xml_parser, "startElement", "endElement");
        xml_set_character_data_handler($this->xml_parser, "characterData");
        if (!xml_parse($this->xml_parser, $data, TRUE)) {
            sprintf("XML error: %s at line %d",
            xml_error_string(xml_get_error_code($this->xml_parser)),
            xml_get_current_line_number($this->xml_parser));
        }
        // we are done with the parser, so let's free it
        xml_parser_free($this->xml_parser);
    }//end constructor: function xml()
}//thus, we end our class xml
?>
操作
[url=javascript:;]方法[/url]
：
require('class.xml.php');
$file = "data.xml";
$data = implode("",file($file)) or die("could not open XML input file");
$obj = new xml($data,"xml");
print $xml["hans"][0]->num_results[0];
for($i=0;$itag[0] . " ";
}
To print url attributes (if they exist):
print $xml["hans"][0]->attributes[0]["size"];