To treat a group of objects the same way as a single instance of the object.

• a form class instance handles all its form elements like a single instance of the form, when render() is called, it subsequently runs through all its child elements and calls render() on them

You can also find this code on GitHub

Renderable.php

.. literalinclude:: Renderable.php
   :language: php
   :linenos:

Form.php

.. literalinclude:: Form.php
   :language: php
   :linenos:

InputElement.php

.. literalinclude:: InputElement.php
   :language: php
   :linenos:

TextElement.php

.. literalinclude:: TextElement.php
   :language: php
   :linenos:

Tests/CompositeTest.php

.. literalinclude:: Tests/CompositeTest.php
   :language: php
   :linenos: