Laravel之Contracts和Facades详解

contracts

contracts其实就是倡导面向接口编程，来达到解耦的目的。而这些通用的接口已经由laravel为你设计好了。就是这些contracts.

那么laravel如何知道我们需要使用哪个实现呢？

在laravel默认的contracts绑定中，在’illuminate/foundation/application.php’有这样的定义:这就是绑定了默认的接口实现.

/**     * register the core class alias in the container.     *     * @return void     */    public function registercorecontaineralias()    {        $alias = [            'app'                  => ['illuminate\foundation\application', 'illuminate\contracts\container\container', 'illuminate\contracts\foundation\application'],            'auth'                 => 'illuminate\auth\authmanager',            'auth.driver'          => ['illuminate\auth\guard', 'illuminate\contracts\auth\guard'],            'auth.password.tokens' => 'illuminate\auth\passwords\tokenrepositoryinterface',            'blade.compiler'       => 'illuminate\view\compilers\bladecompiler',            'cache'                => ['illuminate\cache\cachemanager', 'illuminate\contracts\cache\factory'],            'cache.store'          => ['illuminate\cache\repository', 'illuminate\contracts\cache\repository'],            'config'               => ['illuminate\config\repository', 'illuminate\contracts\config\repository'],            'cookie'               => ['illuminate\cookie\cookiejar', 'illuminate\contracts\cookie\factory', 'illuminate\contracts\cookie\queueingfactory'],            'encrypter'            => ['illuminate\encryption\encrypter', 'illuminate\contracts\encryption\encrypter'],            'db'                   => 'illuminate\databa\databamanager',            'db.connection'        => ['illuminate\databa\connection', 'illuminate\databa\connectioninterface'],            'events'               => ['illuminate\events\dispatcher', 'illuminate\contracts\events\dispatcher'],            'files'                => 'illuminate\filesystem\filesystem',            'filesystem'           => ['illuminate\filesystem\filesystemmanager', 'illuminate\contracts\filesystem\factory'],            'filesystem.disk'      => 'illuminate\contracts\filesystem\filesystem',            'filesystem.cloud'     => 'illuminate\contracts\filesystem\cloud',            'hash'                 => 'illuminate\contracts\hashing\hasher',            'translator'           => ['illuminate\translation\translator', 'symfony\component\translation\translatorinterface'],            'log'                  => ['illuminate\log\writer', 'illuminate\contracts\logging\log', 'psr\log\loggerinterface'],            'mailer'               => ['illuminate\mail\mailer', 'illuminate\contracts\mail\mailer', 'illuminate\contracts\mail\mailqueue'],            'auth.password'        2017春运开始时间=> ['illuminate\auth\passwords\passwordbroker', 'illuminate\contracts\auth\passwordbroker'],            'queue'                => ['illuminate\queue\queuemanager', 'illuminate\contracts\queue\factory', 'illuminate\contracts\queue\monitor'],            'queue.connection'     => 'illuminate\contracts\queue\queue',            'redirect'             => 'illuminate\routing\redirector',            'redis'                => ['illuminate\redis\databa', 'illuminate\contracts\redis\databa'],            'request'              => 'illuminate\http\request',            'router'               => ['illuminate\routing\router', 'illuminate\contracts\routing\registrar'],            'ssion'              => 'illuminate\ssion\ssionmanager',            'ssion.store'        => ['illuminate\ssion\store', 'symfony\component\httpfoundation\ssion\ssioninterface'],            'url'                  => ['illuminate\routing\urlgenerator', 'illuminate\contracts\routing\urlgenerator'],            'validator'            => ['illuminate\validation\factory', 'illuminate\contracts\validation\factory'],            'view'                 => ['illuminate\view\factory', 'illuminate\contracts\view\factory'],        ];

在我们自定义的接口实现时，我们可以在rviceprovider中使用进行绑定:

$this->app->bind('app\contracts\eventpusher', 'app\rvices\pushereventpusher');

facades

facades 为应用程序的服务容器中可用的类提供了一个「静态」接口。laravel 「facades」作为在服务容器内基类的「静态代理」。很难懂？

我们打开项目目录下的config/app.php，然后找到

/*    |--------------------------------------------------------------------------    | class alias    |--------------------------------------------------------------------------    |    | this array of class alias will be registered when this application    | is started. however, feel free to register as many as you wish as    | the alias are "lazy" loaded so they don't hinder performance.    |    */    'alias' => [        'app'       => illuminate\support\facades\app::class,        'artisan'   => illuminate\support\facades\artisan::class,        'auth'      => illuminate\support\facades\auth::class,        'blade'     => illuminate\support\facades\blade::class,        'bus'       => illuminate\support\facades\bus::class,        'cache'     => illuminate\support\facades\cache::class,        'config'    => illuminate\support\facades\config::class,        'cookie'    => illuminate\support\facades\cookie::class,        'crypt'     => illuminate\support\facades\crypt::class,        'db'        => illuminate\support\facades\db::class,        'eloquent'  => illuminate\databa\eloquent\model::class,        'event'     => illuminate\support\facades\event::class,        'file'      => illuminate\support\facades\file::class,        'gate'      => illuminate\support\facades\gate::class,        'hash'      => illuminate\support\facades\hash::class,        'input'     => illuminate\support\facades\input::class,        'lang'      => illuminate\support\facades\lang::class,        'log'       => illuminate\support\facades\log::class,        'mail'      => illuminate\support\facades\mail::class,        'password'  => illuminate\support\facades\password::class,        'queue'     => illuminate\support\facades\queue::class,        'redirect'  => illuminate\support\facades\redirect::class,        'redis'     => illuminate\support\facades\redis::class,        'request'   => illuminate\support\facades\request::class,        'respon'  => illuminate\support\facades\respon::class,        'route'     => illuminate\support\facades\route::class,        'schema'    => illuminate\support\facades\schema::class,        'ssion'   => illuminate\support\facades\ssion::class,        'storage'   => illuminate\support\facades\storage::class,        'url'       => illuminate\support\facades\url::class,        'validator' => illuminate\support\facades\validator::class,        'view'      => illuminate\support\facades\view::class狼之子雨和雪,    ],

你是不是发现了什么？对，facades其实就是在config/app.php中定义的一系列类的别名。只不过这些类都具有一个共同的特点，那就是继承基底 illuminate\support\facades\facade 类并实现一个方法：getfacadeaccessor返回名称。

自定义facade

参考http://www.tutorialspoint.com/laravel/laravel_facades.htm

step 1−创建一个名为 testfacadesrviceprovider的rviceprovider ,使用如下命令即可:

php artisan make:provider testfacadesrviceprovider

step 2− 创建一个底层代理类，命名为“testfacades.php” at “app/test”.

app/test/testfacades.php

<?phpnamespace app\test;class testfacad白蚂蚁es{   public function testingfacades(){      echo "testing the facades in laravel.";   }}?>

step 3− 创建一个 facade 类 called “testfacades.php” at “app/test/facades”.

app/test/facades/testfacades.php

<?phpnamespace app\test\facades;u illuminate\support\facades\facade;class testfacades extends facade{   protected s春天真美tatic function getfacadeaccessor() { return 'test'; }}

step 4−创建一个rviceproviders类，名为“testfacadesrviceproviders.ph世界沙漠p” at “app/test/facades”.

app/providers/testfacadesrviceproviders.php

<?phpnamespace app\providers;u app;u illuminate\support\rviceprovider;class testfacadesrviceprovider extends rviceprovider { public function boot() { // } public function register() { //可以这么绑定,这需要u app; //  app::bind('test',function() { //     return new \app\test\testfacades; //  });   //也可以这么绑定，推荐。这个test对应于facade的getfacadeaccessor返回值 $this->app->bind("test", function(){ return new myfoo(); //给这个facade返回一个代理实例。所有对facade的调用都会被转发到该类对象下。 }); }}

step 5− 在config/app.php注册rviceprovider类

step 6− 在config/app.php注册自定义facade的别名

使用测试：

add the following lines in app/http/routes.php.

route::get('/facadeex', function(){ return testfacades::testingfacades();});

step 9− visit the following url to test the facade.

http://localhost:8000/facadeex去查看输出

更多学习内容请访问：

腾讯t3-t4标准精品php架构师教程目录大全，只要你看完保证薪资上升一个台阶（持续更新）