The strategy mode of PHP design mode

1. Concept

Policy mode: Encapsulates a specific set of behaviors and algorithms into classes to accommodate certain context contexts, which are policy patterns

2. function

Use policy mode to implement IOC, dependency inversion, control inversion

3. For example

If an e-commerce website system, targeting different groups of people to jump to different items, and all advertising sites show different ads

4. The problem to be resolved

1. Do not change the code because of context changes (traditionally used if else to judge)
2. If you add a new type of user, you just need to add a strategy, you do not need to if else continue adding logic in the code
3. Different places only need to implement a different strategy just fine, so you can solve the problem
4. 从硬编码到解耦的使用
5.最主要的是解决了程序中的分支逻辑

5. Actual combat Code Show 5.1 interface file for policy declaration

interface UserStrategy {    function showAd();    function showCategory();

5.2 Defining strategies for female users

class FemaleUserStrategy implements UserStrategy  {    function showAd()    {        echo"2014新款女装";    }    function showCategory()    {        echo"服装";    

5.3 Defining strategies for male users

class MaleUserStrategy implements UserStrategy  {    function showAd()    {        echo"IPhone6";    }    function showCategory()    {        echo"电子产品";    

6. Page display and use

 class Page{    //Save policy Object    protected $strategy;//Home Information output     function index(){        //traditional notation, with output        if(isset($_get[' Famale '])) {Echo ' Women '; }Else if(isset($_get[' Famale '])) {Echo ' Male '; }//If new business logic is added, there will be a lot of if else        //output of the policy mode        Echo $this->strategy->showad ();Echo ' <br> ';Echo $this->strategy->showcategory (); }//Policy mode to resolve, registration policy     function setstrategy(userstrategy $strategy){        $this->strategy =$strategy; }}//Execute$page=NewPage;//Here according to the actual context of the environmentif(isset($_get[' Famale '])) {$strategy=NewFemaleuserstrategy ();}Else if(isset($_get[' Famale '])) {$strategy=NewMaleuserstrategy ();}//Make dependency reversal, final execution in the use of relationship bindings, output (solves the coupling problem of traditional notation)$page->setstrategy ($strategy);$page->index ();

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The strategy mode of PHP design mode