Quero converter abaixo de XML para PHP. Alguma sugestão de como posso fazer isso?

<aaaa Version="1.0">
   <bbb>
     <cccc>
       <dddd Id="id:pass" />
       <eeee name="hearaman" age="24" />
     </cccc>
   </bbb>
</aaaa>

Outra opção é a extensão SimpleXML (acredito que seja padrão na maioria das instalações de php.)

http://php.net/manual/en/book.simplexml.php

A sintaxe se parece com isso no seu exemplo

$xml = new SimpleXMLElement($xmlString);
echo $xml->bbb->cccc->dddd['Id'];
echo $xml->bbb->cccc->eeee['name'];
// or...........
foreach ($xml->bbb->cccc as $element) {
  foreach($element as $key => $val) {
   echo "{$key}: {$val}";
  }
}

fácil!

$xml = simplexml_load_string($xmlstring, "SimpleXMLElement", LIBXML_NOCDATA);
$json = json_encode($xml);
$array = json_decode($json,TRUE);

Convertendo uma string XML ( $buffer) em uma matriz simplificada, ignorando atributos e agrupando elementos filho com os mesmos nomes:

function XML2Array(SimpleXMLElement $parent)
{
    $array = array();

    foreach ($parent as $name => $element) {
        ($node = & $array[$name])
            && (1 === count($node) ? $node = array($node) : 1)
            && $node = & $node[];

        $node = $element->count() ? XML2Array($element) : trim($element);
    }

    return $array;
}

$xml   = simplexml_load_string($buffer);
$array = XML2Array($xml);
$array = array($xml->getName() => $array);

Resultado:

Array
(
    [aaaa] => Array
        (
            [bbb] => Array
                (
                    [cccc] => Array
                        (
                            [dddd] => 
                            [eeee] => 
                        )

                )

        )

)

Se você também deseja ter os atributos, eles estão disponíveis via codificação / decodificação JSON do SimpleXMLElement. Geralmente, essa é a solução quick'n'dirty mais fácil:

$xml   = simplexml_load_string($buffer);
$array = json_decode(json_encode((array) $xml), true);
$array = array($xml->getName() => $array);

Resultado:

Array
(
    [aaaa] => Array
        (
            [@attributes] => Array
                (
                    [Version] => 1.0
                )

            [bbb] => Array
                (
                    [cccc] => Array
                        (
                            [dddd] => Array
                                (
                                    [@attributes] => Array
                                        (
                                            [Id] => id:pass
                                        )

                                )

                            [eeee] => Array
                                (
                                    [@attributes] => Array
                                        (
                                            [name] => hearaman
                                            [age] => 24
                                        )

                                )

                        )

                )

        )

)

Observe que todos esses métodos funcionam apenas no espaço para nome do documento XML.

$array = json_decode(json_encode((array)simplexml_load_string($xml)),true);

Surpreendido, ninguém mencionou xml_parse_into_struct:

$simple = "<para><note>simple note</note></para>";
$p = xml_parser_create();
xml_parse_into_struct($p, $simple, $vals, $index);
xml_parser_free($p);
echo "Index array\n";
print_r($index);
echo "\nVals array\n";
print_r($vals);

Consulte https://github.com/gaarf/XML-string-to-PHP-array/blob/master/xmlstr_to_array.php

<?php
/**
  * convert xml string to php array - useful to get a serializable value
  *
  * @param string $xmlstr
  * @return array
  *
  * @author Adrien aka Gaarf & contributors
  * @see http://gaarf.info/2009/08/13/xml-string-to-php-array/
*/
function xmlstr_to_array($xmlstr) {
  $doc = new DOMDocument();
  $doc->loadXML($xmlstr);
  $root = $doc->documentElement;
  $output = domnode_to_array($root);
  $output['@root'] = $root->tagName;
  return $output;
}
function domnode_to_array($node) {
  $output = array();
  switch ($node->nodeType) {
    case XML_CDATA_SECTION_NODE:
    case XML_TEXT_NODE:
      $output = trim($node->textContent);
    break;
    case XML_ELEMENT_NODE:
      for ($i=0, $m=$node->childNodes->length; $i<$m; $i++) {
        $child = $node->childNodes->item($i);
        $v = domnode_to_array($child);
        if(isset($child->tagName)) {
          $t = $child->tagName;
          if(!isset($output[$t])) {
            $output[$t] = array();
          }
          $output[$t][] = $v;
        }
        elseif($v || $v === '0') {
          $output = (string) $v;
        }
      }
      if($node->attributes->length && !is_array($output)) { //Has attributes but isn't an array
        $output = array('@content'=>$output); //Change output into an array.
      }
      if(is_array($output)) {
        if($node->attributes->length) {
          $a = array();
          foreach($node->attributes as $attrName => $attrNode) {
            $a[$attrName] = (string) $attrNode->value;
          }
          $output['@attributes'] = $a;
        }
        foreach ($output as $t => $v) {
          if(is_array($v) && count($v)==1 && $t!='@attributes') {
            $output[$t] = $v[0];
          }
        }
      }
    break;
  }
  return $output;
}

O método usado na resposta aceita descarta atributos ao encontrar elementos filho apenas com um nó de texto. Por exemplo:

$xml = '<container><element attribute="123">abcd</element></container>';
print_r(json_decode(json_encode(simplexml_load_string($xml, "SimpleXMLElement", LIBXML_NOCDATA)),1));

Array
(
    [element] => abcd
)

Minha solução (e eu gostaria de poder dar crédito aqui, porque tenho certeza de que adaptei isso de alguma coisa):

function XMLtoArray($xml) {
    $previous_value = libxml_use_internal_errors(true);
    $dom = new DOMDocument('1.0', 'UTF-8');
    $dom->preserveWhiteSpace = false; 
    $dom->loadXml($xml);
    libxml_use_internal_errors($previous_value);
    if (libxml_get_errors()) {
        return [];
    }
    return DOMtoArray($dom);
}

function DOMtoArray($root) {
    $result = array();

    if ($root->hasAttributes()) {
        $attrs = $root->attributes;
        foreach ($attrs as $attr) {
            $result['@attributes'][$attr->name] = $attr->value;
        }
    }

    if ($root->hasChildNodes()) {
        $children = $root->childNodes;
        if ($children->length == 1) {
            $child = $children->item(0);
            if (in_array($child->nodeType,[XML_TEXT_NODE,XML_CDATA_SECTION_NODE])) {
                $result['_value'] = $child->nodeValue;
                return count($result) == 1
                    ? $result['_value']
                    : $result;
            }

        }
        $groups = array();
        foreach ($children as $child) {
            if (!isset($result[$child->nodeName])) {
                $result[$child->nodeName] = DOMtoArray($child);
            } else {
                if (!isset($groups[$child->nodeName])) {
                    $result[$child->nodeName] = array($result[$child->nodeName]);
                    $groups[$child->nodeName] = 1;
                }
                $result[$child->nodeName][] = DOMtoArray($child);
            }
        }
    }
    return $result;
}

$xml = '
    <aaaa Version="1.0">
       <bbb>
         <cccc>
           <dddd id="123" />
           <eeee name="john" age="24" />
           <ffff type="employee">Supervisor</ffff>
         </cccc>
       </bbb>
    </aaaa>
';
print_r(XMLtoArray($xml));

Array
(
    [aaaa] => Array
        (
            [@attributes] => Array
                (
                    [Version] => 1.0
                )

            [bbb] => Array
                (
                    [cccc] => Array
                        (
                            [dddd] => Array
                                (
                                    [@attributes] => Array
                                        (
                                            [id] => 123
                                        )

                                )

                            [eeee] => Array
                                (
                                    [@attributes] => Array
                                        (
                                            [name] => john
                                            [age] => 24
                                        )

                                )

                            [ffff] => Array
                                (
                                    [@attributes] => Array
                                        (
                                            [type] => employee
                                        )

                                    [_value] => Supervisor
                                )

                        )

                )

        )

)

XML para matriz

Mais detalhes Visite https://github.com/sapankumarmohanty/lamp/blob/master/Crate-XML-2-Array

// Converter XML em matriz e SOAP XML em matriz

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; //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 ( $attr == 'ResStatus' ) {
                                        $current[$attr][] = $val;
                                    }
                    if ($priority == 'tag') $attributes_data[$attr] = $val;
                    else $result['attr'][$attr] = $val; //Set all the attributes in a array called 'attr'
                }
            }
            // See tag status and do the needed.
                        //echo"<br/> Type:".$type;
            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'] = $attributes_data;
                                        //print_r($current[$tag . '_attr']);
                    $repeated_tag_index[$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);
    }
    
    // Let's call the this above function xml2array
    
    xml2array($xmlContent, $get_attributes = 3, $priority = 'tag'); // it will work 100% if not ping me @skype: sapan.mohannty
    
//  Enjoy coding

Eu gostei desta pergunta e algumas respostas foram úteis para mim, mas preciso converter o xml em uma matriz de dominação, para publicar minha solução, talvez alguém precise dela mais tarde:

<?php
$xml = json_decode(json_encode((array)simplexml_load_string($xml)),1);
$finalItem = getChild($xml);
var_dump($finalItem);

function getChild($xml, $finalItem = []){
    foreach($xml as $key=>$value){
        if(!is_array($value)){
            $finalItem[$key] = $value;
        }else{
            $finalItem = getChild($value, $finalItem);
        }
    }
    return $finalItem;
}
?>