PHP中的类－操作XML(3)

/* 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;
   }



   /* 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;
   }


   /* this is the constructor: automatically called when the class is initialized */

   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

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