Strategy__

Terminology:

• Context
• Strategy
• Concrete Strategy

Purpose

To separate strategies and to enable fast switching between them. Also this pattern is a good alternative to inheritance (instead of having an abstract class that is extended).

Examples

• sorting a list of objects, one strategy by date, the other by id
• simplify unit testing: e.g. switching between file and in-memory storage

UML Diagram

.. image:: uml/uml.png :alt: Alt Strategy UML Diagram :align: center

Code

You can also find this code on GitHub_

Context.php

.. literalinclude:: Context.php :language: php :linenos:

Comparator.php

.. literalinclude:: Comparator.php :language: php :linenos:

DateComparator.php

.. literalinclude:: DateComparator.php :language: php :linenos:

IdComparator.php

.. literalinclude:: IdComparator.php :language: php :linenos:

Test

Tests/StrategyTest.php

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

.. _GitHub: https://github.com/DesignPatternsPHP/DesignPatternsPHP/tree/main/Behavioral/Strategy .. __: http://en.wikipedia.org/wiki/Strategy_pattern