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27 lines
697 B
PHP
27 lines
697 B
PHP
<?php
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namespace DesignPatterns\Observer;
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/**
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* Observer pattern
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*
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* Purpose:
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* to implement a publish/subscribe behaviour to an object, whenever a "Subject" object changes it's state, the attached
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* "Observers" will be notified. It is used to shorten the amount of coupled objects and uses loose coupling instead
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*
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* Examples:
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* - a message queue system is observed to show the progress of a job in a GUI
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*
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* PHP already defines two interfaces that can help to implement this pattern: SplObserver and SplSubject
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*
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*/
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class UserObserver implements \SplObserver
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{
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public function update(\SplSubject $subject)
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{
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echo get_class($subject) . ' has been updated';
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}
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}
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