Encapsulate varying behavior for the same routine based on an object's state. This can be a cleaner way for an object to change its behavior at runtime without resorting to large monolithic conditional statements.

You can also find this code on GitHub

ContextOrder.php

.. literalinclude:: ContextOrder.php
   :language: php
   :linenos:

StateOrder.php

.. literalinclude:: StateOrder.php
   :language: php
   :linenos:

CreateOrder.php

.. literalinclude:: CreateOrder.php
   :language: php
   :linenos:

ShippingOrder.php

.. literalinclude:: ShippingOrder.php
   :language: php
   :linenos:

OrderDone.php

.. literalinclude:: OrderDone.php
   :language: php
   :linenos:

Tests/StateTest.php

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