Object Representation - PHP

I'm trying to understand how to best represent data which eventually I'll pull out and build JSON / XML from.. however I keep running in circles of how to define the object..

Essentially I want to represent a parent / child relationship along with what attributes are on the item. Such that I could build a JSON or XML element.

Has anyone worked with something like this before or have any ideas on how to work through it?

My XML built would look something like:

<props>开发者_Python百科
  <items>
    <item id='foo'/>
    <item id='foo2' />
  </items>
  <bar>
    <test>
       <tree>This Data</tree>
       <tree>That Data</tree>
    </test>
  </bar>
</props>

I thought of some how trying to represent each data item in an object as:

class ItemResource {
  private $key;
  private $value;
  private $attribute_list = array();

  public function __construct($key, $value, array $attributeList=null){
      $this->key = $key;
      $this->value = $value;
      if($attributeList!=null){  
          //do stuff 
          $this->attribute_list = $attributeList;
      }
    }

}

Sounds like an excellent job for PHP's Array. You can build infinitely large key-value hierarchies using associative arrays.

$itemresource = array(
    "key" => $key,
    "value" => $value,
    "attribute_list" => array(
        "foo" => "bar",
        "some" => "value"
    )
);

Associative arrays are also probably the input for XML generators (Although that's guesswork from my side)

You can also easily print your arrays out in JSON using json_encode