To translate one interface for a class into a compatible interface. An adapter allows classes to work together that normally could not because of incompatible interfaces by providing its interface to clients while using the original interface.

• DB Client libraries adapter
• using multiple different webservices and adapters normalize data so that the outcome is the same for all

You can also find this code on GitHub

Book.php

.. literalinclude:: Book.php
   :language: php
   :linenos:

PaperBook.php

.. literalinclude:: PaperBook.php
   :language: php
   :linenos:

EBook.php

.. literalinclude:: EBook.php
   :language: php
   :linenos:

EBookAdapter.php

.. literalinclude:: EBookAdapter.php
   :language: php
   :linenos:

Kindle.php

.. literalinclude:: Kindle.php
   :language: php
   :linenos:

Tests/AdapterTest.php

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