php之XML轉數組函數的詳解

<?
/** 
* xml2array() will convert the given XML text to an array in the XML structure. 
* Link: http://www.bin-co.com/php/scripts/xml2array/ 
* Arguments : $contents - The XML text 
*                 $get_attributes - 1 or 0. If this is 1 the function will get the attributes as well as the tag values - this results in a different array structure in the return value. 
*                 $priority - Can be &#39;tag&#39; or &#39;attribute&#39;. This will change the way the resulting array sturcture. For &#39;tag&#39;, the tags are given more importance. 
* Return: The parsed XML in an array form. Use print_r() to see the resulting array structure. 
* Examples: $array =   xml2array(file_get_contents(&#39;feed.xml&#39;)); 
*               $array =   xml2array(file_get_contents(&#39;feed.xml&#39;, 1, &#39;attribute&#39;)); 
*/ 
function xml2array($contents, $get_attributes=1, $priority = &#39;tag&#39;) { 
     if(!$contents) return array(); 
     if(!function_exists(&#39;xml_parser_create&#39;)) { 
        //print "&#39;xml_parser_create()&#39; function not found!"; 
        return array(); 
     } 
    //Get the XML parser of PHP - PHP must have this module for the parser to work 
    $parser = xml_parser_create(&#39;&#39;); 
    xml_parser_set_option($parser, XML_OPTION_TARGET_ENCODING, "UTF-8"); # http://minutillo.com/steve/weblog/2004/6/17/php-xml-and-character-encodings-a-tale-of-sadness-rage-and-data-loss 
    xml_parser_set_option($parser, XML_OPTION_CASE_FOLDING, 0); 
    xml_parser_set_option($parser, XML_OPTION_SKIP_WHITE, 1); 
    xml_parse_into_struct($parser, trim($contents), $xml_values); 
    xml_parser_free($parser); 
     if(!$xml_values) return;//Hmm... 
     //Initializations 
    $xml_array = array(); 
    $parents = array(); 
    $opened_tags = array(); 
    $arr = array(); 
    $current = &$xml_array; //Refference 
     //Go through the tags. 
    $repeated_tag_index = array();//Multiple tags with same name will be turned into an array 
    foreach($xml_values as $data) { 
         unset($attributes,$value);//Remove existing values, or there will be trouble 
         //This command will extract these variables into the foreach scope 
         // tag(string), type(string), level(int), attributes(array). 
        extract($data);//We could use the array by itself, but this cooler. 
        $result = array(); 
        $attributes_data = array(); 

         if(isset($value)) { 
             if($priority == &#39;tag&#39;) $result = $value; 
             else $result[&#39;value&#39;] = $value; //Put the value in a assoc array if we are in the &#39;Attribute&#39; mode 
        } 
        //Set the attributes too. 
        if(isset($attributes) and $get_attributes) { 
             foreach($attributes as $attr => $val) { 
                 if($priority == &#39;tag&#39;) $attributes_data[$attr] = $val; 
                 else $result[&#39;attr&#39;][$attr] = $val; //Set all the attributes in a array called &#39;attr&#39; 
            } 
         } 
        //See tag status and do the needed. 
        if($type == "open") {//The starting of the tag &#39;<tag>&#39; 
            $parent[$level-1] = &$current; 
             if(!is_array($current) or (!in_array($tag, array_keys($current)))) { //Insert New tag 
                $current[$tag] = $result; 
                 if($attributes_data) $current[$tag. &#39;_attr&#39;] = $attributes_data; 
                $repeated_tag_index[$tag.&#39;_&#39;.$level] = 1; 
                $current = &$current[$tag]; 
             } else { //There was another element with the same tag name 
                if(isset($current[$tag][0])) {//If there is a 0th element it is already an array 
                    $current[$tag][$repeated_tag_index[$tag.&#39;_&#39;.$level]] = $result; 
                    $repeated_tag_index[$tag.&#39;_&#39;.$level]++; 
                 } else {//This section will make the value an array if multiple tags with the same name appear together 
                    $current[$tag] = array($current[$tag],$result);//This will combine the existing item and the new item together to make an array 
                    $repeated_tag_index[$tag.&#39;_&#39;.$level] = 2; 

                     if(isset($current[$tag.&#39;_attr&#39;])) { //The attribute of the last(0th) tag must be moved as well 
                        $current[$tag][&#39;0_attr&#39;] = $current[$tag.&#39;_attr&#39;]; 
                         unset($current[$tag.&#39;_attr&#39;]); 
                     } 
                 } 
                $last_item_index = $repeated_tag_index[$tag.&#39;_&#39;.$level]-1; 
                $current = &$current[$tag][$last_item_index]; 
             } 
         } elseif($type == "complete") { //Tags that ends in 1 line &#39;<tag />&#39; 
             //See if the key is already taken. 
            if(!isset($current[$tag])) { //New Key 
                $current[$tag] = $result; 
                $repeated_tag_index[$tag.&#39;_&#39;.$level] = 1; 
                 if($priority == &#39;tag&#39; and $attributes_data) $current[$tag. &#39;_attr&#39;] = $attributes_data; 
             } else { //If taken, put all things inside a list(array) 
                if(isset($current[$tag][0]) and is_array($current[$tag])) {//If it is already an array... 
                     // ...push the new element into that array. 
                    $current[$tag][$repeated_tag_index[$tag.&#39;_&#39;.$level]] = $result; 

                     if($priority == &#39;tag&#39; and $get_attributes and $attributes_data) { 
                        $current[$tag][$repeated_tag_index[$tag.&#39;_&#39;.$level] . &#39;_attr&#39;] = $attributes_data; 
                     } 
                    $repeated_tag_index[$tag.&#39;_&#39;.$level]++; 
                 } else { //If it is not an array... 
                    $current[$tag] = array($current[$tag],$result); //...Make it an array using using the existing value and the new value 
                    $repeated_tag_index[$tag.&#39;_&#39;.$level] = 1; 
                     if($priority == &#39;tag&#39; and $get_attributes) { 
                         if(isset($current[$tag.&#39;_attr&#39;])) { //The attribute of the last(0th) tag must be moved as well 

                            $current[$tag][&#39;0_attr&#39;] = $current[$tag.&#39;_attr&#39;]; 
                             unset($current[$tag.&#39;_attr&#39;]); 
                         } 

                         if($attributes_data) { 
                            $current[$tag][$repeated_tag_index[$tag.&#39;_&#39;.$level] . &#39;_attr&#39;] = $attributes_data; 
                         } 
                     } 
                    $repeated_tag_index[$tag.&#39;_&#39;.$level]++; //0 and 1 index is already taken 
                } 
             } 
         } elseif($type == &#39;close&#39;) { //End of tag &#39;</tag>&#39; 
            $current = &$parent[$level-1]; 
         } 
     } 

     return($xml_array); 
} 
?>

$arr = xml2array(file_get_contents("tools.xml"),1,'attribute');