XML与数据格式进行转换类

<?php
/**
 * xml2array() will convert the given XML text to an array in the XML structure. 
 * Link: http://www.php.cn/ 
 * 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 'tag' or 'attribute'. This will change the way the resulting array sturcture. For 'tag', 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('feed.xml')); 
 * $array =  xml2array(file_get_contents('feed.xml', 1, 'attribute'));
 */
function xml2array($contents, $get_attributes = 1, $priority = 'tag') {
    if (!$contents) return array();

    if (!function_exists('xml_parser_create')) {
        // print "'xml_parser_create()' function not found!";
        return array();
    } 
    // Get the XML parser of PHP - PHP must have this module for the parser to work
    $parser = xml_parser_create('');
    xml_parser_set_option($parser, XML_OPTION_TARGET_ENCODING, "UTF-8"); # http://www.php.cn/ 
    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 == 'tag') $result = $value;
            else $result['value'] = $value; //Put the value in a assoc array if we are in the 'Attribute' mode 
        } 
        // Set the attributes too.
        if (isset($attributes) and $get_attributes) {
            foreach($attributes as $attr => $val) {
                if ($priority == 'tag') $attributes_data[$attr] = $val;
                else $result['attr'][$attr] = $val; //Set all the attributes in a array called 'attr' 
            } 
        } 
        // See tag status and do the needed.
        if ($type == "open") { // The starting of the tag '<tag>'
            $parent[$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 . '_attr'] = $attributes_data;
                $repeated_tag_index[$tag . '_' . $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 . '_' . $level]] = $result;
                    $repeated_tag_index[$tag . '_' . $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 . '_' . $level] = 2;

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

                    if ($priority == 'tag' and $get_attributes and $attributes_data) {
                        $current[$tag][$repeated_tag_index[$tag . '_' . $level] . '_attr'] = $attributes_data;
                    } 
                    $repeated_tag_index[$tag . '_' . $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 . '_' . $level] = 1;
                    if ($priority == 'tag' and $get_attributes) {
                        if (isset($current[$tag . '_attr'])) { // The attribute of the last(0th) tag must be moved as well
                            $current[$tag]['0_attr'] = $current[$tag . '_attr'];
                            unset($current[$tag . '_attr']);
                        } 

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

    return($xml_array);
} 

// Array to XML
class array2xml {
    public $output = "<?xml version=\"1.0\" encoding=\"utf-8\"?>\n";
    public $sub_item = array();
    public function __construct($array) {
        $sub_item = array();
        $this->output .= $this->xmlmake($array);
    } 
    public function xmlmake($array, $fk = '') {
        $xml = '';
        global $sub_item;
        foreach ($array as $key => $value) {
            if (is_array($value)) {
                if (is_numeric($key)) {
                    $this->sub_item=array_merge($this->sub_item,array($fk));
                    $xml .= "<{$fk}>" . $this->xmlmake($value, $key) . "</{$fk}>";
                } else {
                    $xml .= "<{$key}>" . $this->xmlmake($value, $key) . "</{$key}>";
                } 
            } else {
                $xml .= "<{$key}>{$value}</{$key}>\n";
            } 
        } 
        return $xml;
    } 
    public function output(){
        foreach($this->sub_item as $t){
            $this->output = str_replace("<{$t}><{$t}>","<{$t}>",$this->output);
            $this->output = str_replace("</{$t}></{$t}>","</{$t}>",$this->output);
        }
        return $this->output;
    }
}