Singleton__

THIS IS CONSIDERED TO BE AN ANTI-PATTERN! FOR BETTER TESTABILITY AND MAINTAINABILITY USE DEPENDENCY INJECTION!

Purpose

To have only one instance of this object in the application that will handle all calls.

Examples

• DB Connector
• Logger
• Config Manager
• Threads Handling
• Lock file for the application (there is only one in the filesystem ...)

UML Diagram

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

Code

You can also find this code on GitHub_

Singleton.php

.. literalinclude:: Singleton.php :language: php :linenos:

Test

Tests/SingletonTest.php

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

.. _GitHub: https://github.com/DesignPatternsPHP/DesignPatternsPHP/tree/main/Creational/Singleton .. __: http://en.wikipedia.org/wiki/Singleton_pattern