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DesignPatternsPHP/Behavioral/Visitor/README.md
2014-07-31 14:13:53 -05:00

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# Visitor
## Purpose
The Visitor Pattern lets you outsource operations on objects to other objects. The main reason to do this is to keep a separation of concerns.
But classes have to define a contract to allow visitors (the `Role::accept` method in the example).
The contract is an abstract class but you can have also a clean interface. In that case, each Visitor has to choose itself which method to invoke on the visitor.
## UML Diagram
![Alt Visitor UML Diagram](uml/uml.png)