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一个操作xml的PHP类（附使用方法）

<?php
/**
* @copyright 互联网
* 整理：[url]www.phppx.com[/url]
* @desc 一个操作xml的PHP类
*/

/*
   (c) 2000 Hans Anderson Corporation.  All Rights Reserved.
   You are free to use and modify this class under the same
   guidelines found in the PHP License.

   ———–

   bugs/me:
   [url]http://www.hansanderson.com/php/[/url]
   [email]me@hansanderson.com[/email]
   [email]showstv@163.com[/email]

   ———–

   Version 1.0

      – 1.0 is the first actual release of the class.  It”s 
       finally what I was hoping it would be, though there
       are likely to still be some bugs in it.  This is
       a much changed version, and if you have downloaded
       a previous version, this WON”T work with your existing
       scripts!  You”ll need to make some SIMPLE changes.

      – .92 fixed bug that didn”t include tag attributes

       (to use attributes, add _attributes[array_index]
        to the end of the tag in question:
        $xml_html_head_body_img would become
        $xml_html_head_body_img_attributes[0], 
        for example)

        — Thanks to Nick Winfield <[email]nick@wirestation.co.uk[/email]>
          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 XML 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

?>

使用方法：

<?php
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;$i<sizeof($xml["hans"]);$i++) {
        print $xml["hans"][$i]->tag[0] . ” “;
}

//To print url attributes (if they exist):

print $xml["hans"][0]->attributes[0]["size"];

?>