PHP design pattern-PHP source code

Introduction to the policy pattern of PHP design pattern

Policy mode: defines algorithm families, which are encapsulated separately so that they can be replaced with each other. This mode allows algorithm changes to be independent of algorithm customers.

Encapsulation: encapsulate behavior with interfaces. we can extract frequently changed parts from the current class and encapsulate them separately using interfaces.

Replace each other: we have encapsulated interfaces and implemented classes to change algorithms by specifying different interfaces.

Mind Map

 
class Duck{    private $_flyBehavior;    public function performFly(){        $this->_flyBehavior->fly();    }    public function setFlyBehavior(FlyBehavior $behavior){        $this->_flyBehavior = $behavior;    }}class RubberDuck extends Duck{}
// Test Case $ duck = new RubberDuck ();/* fly the duck with wings */$ duck-> setFlyBehavior (new FlyWithWings ()); $ duck-> mongomfly ();/* fly the duck without wings */$ duck-> setFlyBehavior (new FlyWithNo (); $ duck-> mongomfly ();
 
Summary
In general, our design principles in development are as follows:
1. identify potential changes in the application and separate them from those that do not need to be changed;
2. interface programming, not implementation programming;
3. multi-purpose combination and less inheritance;
 
References: head first design model