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58 lines
1.0 KiB
ReStructuredText
58 lines
1.0 KiB
ReStructuredText
`Observer`__
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============
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Purpose
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-------
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To implement a publish/subscribe behaviour to an object, whenever a
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"Subject" object changes it's state, the attached "Observers" will be
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notified. It is used to shorten the amount of coupled objects and uses
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loose coupling instead.
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Examples
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--------
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- a message queue system is observed to show the progress of a job in a
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GUI
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Note
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----
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PHP already defines two interfaces that can help to implement this
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pattern: SplObserver and SplSubject.
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UML Diagram
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-----------
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.. image:: uml/uml.png
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:alt: Alt Observer UML Diagram
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:align: center
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Code
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----
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You can also find these code on `GitHub`_
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User.php
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.. literalinclude:: User.php
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:language: php
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:linenos:
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UserObserver.php
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.. literalinclude:: UserObserver.php
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:language: php
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:linenos:
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Test
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----
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Tests/ObserverTest.php
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.. literalinclude:: Tests/ObserverTest.php
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:language: php
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:linenos:
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.. _`GitHub`: https://github.com/domnikl/DesignPatternsPHP/tree/master/Behavioral/Observer
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.. __: http://en.wikipedia.org/wiki/Observer_pattern |