Yo uso una clase frankestein combinando varias que he encontrado en la web para trabajar con arrays, te dejo el codigo
Código PHP:
<?PHP
/*************************************************************************/
/* This class stores associative arrays in an xml formated string. */
/* There's also a function thar retrieves them. If you try to use */
/* xml2array with a general xml, it can fail, since there can be some */
/* repeated indexes.... */
/*************************************************************************/
/*************************************************************************/
/* Use:
/*
<?PHP
include('assoc_array2xml.php');
$example_array=array('one'=>'23','two'=>array('subone'=>'22',subtwo=>'233'),'three'=>'2');
$converter= new assoc_array2xml;
$string=$converter->array2xml($example_array);
echo "******\n$string\n********\n";
$array=$converter->xml2array($string);
print_r($array);
?>
*/
class assoc_array2xml {
var $text;
var $arrays, $keys, $node_flag, $depth, $xml_parser;
/*Converts an array to an xml string*/
function array2xml($array) {
//global $text;
$this->text="<?xml version=\"1.0\" encoding=\"iso-8859-1\"?><array>";
$this->text.= $this->array_transform($array);
$this->text .="</array>";
return $this->text;
}
function array_transform($array){
//global $array_text;
foreach($array as $key => $value){
if(!is_array($value)){
$this->text .= "<$key>$value</$key>";
} else {
$this->text.="<$key>";
$this->array_transform($value);
$this->text.="</$key>";
}
}
return $array_text;
}
function startElement($parser, $name, $attrs)
{
$this->keys[]=$name; //We add a key
$this->node_flag=1;
$this->depth++;
}
function characterData($parser,$data)
{
$key=end($this->keys);
$this->arrays[$this->depth][$key]=$data;
$this->node_flag=0; //So that we don't add as an array, but as an element
}
function endElement($parser, $name)
{
$key=array_pop($this->keys);
//If $node_flag==1 we add as an array, if not, as an element
if($this->node_flag==1){
$this->arrays[$this->depth][$key]=$this->arrays[$this->depth+1];
unset($this->arrays[$this->depth+1]);
}
$this->node_flag=1;
$this->depth--;
}
//Returns an array from an xml file.
function xml2array($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://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; //Reference
//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);
}
}//End of the class
?>
El codigo no es mio, pero me ha funcionado siempre que lo he usado, hay dos funciones para pasar de xml a array y de array a xml.
Espero te sirva
03/08/2011, 09:38
Respuesta: Parsear un Array a Un XML. 
hay de todo y para todo ty. 
