Contracts

Contracts其實就是倡導面向接口編程，來達到解耦的目的。而這些通用的接口已經(jīng)由Laravel為你設(shè)計好了。就是這些Contracts.

那么Laravel如何知道我們需要使用哪個實現(xiàn)呢？

在Laravel默認的Contracts綁定中，在'Illuminate/Foundation/Application.php'有這樣的定義:這就是綁定了默認的接口實現(xiàn).

推薦：《laravel教程》

/**      * Register the core class aliases in the container.      *      * @return void      */     public function registerCoreContainerAliases()     {         $aliases = [             'app'                  => ['IlluminateFoundationApplication', 'IlluminateContractsContainerContainer', 'IlluminateContractsFoundationApplication'],             'auth'                 => 'IlluminateAuthAuthManager',             'auth.driver'          => ['IlluminateAuthGuard', 'IlluminateContractsAuthGuard'],             'auth.password.tokens' => 'IlluminateAuthPasswordsTokenRepositoryInterface',             'blade.compiler'       => 'IlluminateViewCompilersBladeCompiler',             'cache'                => ['IlluminateCacheCacheManager', 'IlluminateContractsCacheFactory'],             'cache.store'          => ['IlluminateCacheRepository', 'IlluminateContractsCacheRepository'],             'config'               => ['IlluminateConfigRepository', 'IlluminateContractsConfigRepository'],             'cookie'               => ['IlluminateCookieCookieJar', 'IlluminateContractsCookieFactory', 'IlluminateContractsCookieQueueingFactory'],             'encrypter'            => ['IlluminateEncryptionEncrypter', 'IlluminateContractsEncryptionEncrypter'],             'db'                   => 'IlluminateDatabaseDatabaseManager',             'db.connection'        => ['IlluminateDatabaseConnection', 'IlluminateDatabaseConnectionInterface'],             'events'               => ['IlluminateEventsDispatcher', 'IlluminateContractsEventsDispatcher'],             'files'                => 'IlluminateFilesystemFilesystem',             'filesystem'           => ['IlluminateFilesystemFilesystemManager', 'IlluminateContractsFilesystemFactory'],             'filesystem.disk'      => 'IlluminateContractsFilesystemFilesystem',             'filesystem.cloud'     => 'IlluminateContractsFilesystemCloud',             'hash'                 => 'IlluminateContractsHashingHasher',             'translator'           => ['IlluminateTranslationTranslator', 'SymfonyComponentTranslationTranslatorInterface'],             'log'                  => ['IlluminateLogWriter', 'IlluminateContractsLoggingLog', 'PsrLogLoggerInterface'],             'mailer'               => ['IlluminateMailMailer', 'IlluminateContractsMailMailer', 'IlluminateContractsMailMailQueue'],             'auth.password'        => ['IlluminateAuthPasswordsPasswordBroker', 'IlluminateContractsAuthPasswordBroker'],             'queue'                => ['IlluminateQueueQueueManager', 'IlluminateContractsQueueFactory', 'IlluminateContractsQueueMonitor'],             'queue.connection'     => 'IlluminateContractsQueueQueue',             'redirect'             => 'IlluminateRoutingRedirector',             'redis'                => ['IlluminateRedisDatabase', 'IlluminateContractsRedisDatabase'],             'request'              => 'IlluminateHttpRequest',             'router'               => ['IlluminateRoutingRouter', 'IlluminateContractsRoutingRegistrar'],             'session'              => 'IlluminateSessionSessionManager',             'session.store'        => ['IlluminateSessionStore', 'SymfonyComponentHttpFoundationSessionSessionInterface'],             'url'                  => ['IlluminateRoutingUrlGenerator', 'IlluminateContractsRoutingUrlGenerator'],             'validator'            => ['IlluminateValidationFactory', 'IlluminateContractsValidationFactory'],             'view'                 => ['IlluminateViewFactory', 'IlluminateContractsViewFactory'],         ];

在我們自定義的接口實現(xiàn)時，我們可以在ServiceProvider中使用進行綁定:

$this->app->bind('AppContractsEventPusher', 'AppServicesPusherEventPusher');

Facades

Facades 為應(yīng)用程序的服務(wù)容器中可用的類提供了一個「靜態(tài)」接口。Laravel 「facades」作為在服務(wù)容器內(nèi)基類的「靜態(tài)代理」。很難懂？

我們打開項目目錄下的config/app.php，然后找到

/*     |--------------------------------------------------------------------------     | Class Aliases     |--------------------------------------------------------------------------     |     | This array of class aliases will be registered when this application     | is started. However, feel free to register as many as you wish as     | the aliases are "lazy" loaded so they don't hinder performance.     |     */     'aliases' => [         'App'       => IlluminateSupportFacadesApp::class,         'Artisan'   => IlluminateSupportFacadesArtisan::class,         'Auth'      => IlluminateSupportFacadesAuth::class,         'Blade'     => IlluminateSupportFacadesBlade::class,         'Bus'       => IlluminateSupportFacadesBus::class,         'Cache'     => IlluminateSupportFacadesCache::class,         'Config'    => IlluminateSupportFacadesConfig::class,         'Cookie'    => IlluminateSupportFacadesCookie::class,         'Crypt'     => IlluminateSupportFacadesCrypt::class,         'DB'        => IlluminateSupportFacadesDB::class,         'Eloquent'  => IlluminateDatabaseEloquentModel::class,         'Event'     => IlluminateSupportFacadesEvent::class,         'File'      => IlluminateSupportFacadesFile::class,         'Gate'      => IlluminateSupportFacadesGate::class,         'Hash'      => IlluminateSupportFacadesHash::class,         'Input'     => IlluminateSupportFacadesInput::class,         'Lang'      => IlluminateSupportFacadesLang::class,         'Log'       => IlluminateSupportFacadesLog::class,         'Mail'      => IlluminateSupportFacadesMail::class,         'Password'  => IlluminateSupportFacadesPassword::class,         'Queue'     => IlluminateSupportFacadesQueue::class,         'Redirect'  => IlluminateSupportFacadesRedirect::class,         'Redis'     => IlluminateSupportFacadesRedis::class,         'Request'   => IlluminateSupportFacadesRequest::class,         'Response'  => IlluminateSupportFacadesResponse::class,         'Route'     => IlluminateSupportFacadesRoute::class,         'Schema'    => IlluminateSupportFacadesSchema::class,         'Session'   => IlluminateSupportFacadesSession::class,         'Storage'   => IlluminateSupportFacadesStorage::class,         'URL'       => IlluminateSupportFacadesURL::class,         'Validator' => IlluminateSupportFacadesValidator::class,         'View'      => IlluminateSupportFacadesView::class,     ],

你是不是發(fā)現(xiàn)了什么？對，F(xiàn)acades其實就是在config/app.php中定義的一系列類的別名。只不過這些類都具有一個共同的特點，那就是繼承基底 IlluminateSupportFacadesFacade 類并實現(xiàn)一個方法：getFacadeAccessor返回名稱。

自定義Facade

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

Step 1 ?創(chuàng)建一個名為 TestFacadesServiceProvider的ServiceProvider ,使用如下命令即可:

php artisan make:provider TestFacadesServiceProvider

Step 2 ? 創(chuàng)建一個底層代理類，命名為“TestFacades.php” at “App/Test”.

App/Test/TestFacades.php

<?php namespace AppTest; class TestFacades{    public function testingFacades(){       echo "Testing the Facades in Laravel.";    } } ?>

Step 3 ? 創(chuàng)建一個 Facade 類 called “TestFacades.php” at “App/Test/Facades”.

App/Test/Facades/TestFacades.php

<?php namespace appTestFacades; use IlluminateSupportFacadesFacade; class TestFacades extends Facade{    protected static function getFacadeAccessor() { return 'test'; } }

Step 4 ?創(chuàng)建一個ServiceProviders類，名為“TestFacadesServiceProviders.php” at “App/Test/Facades”.

App/Providers/TestFacadesServiceProviders.php

<?php namespace AppProviders; use App; use IlluminateSupportServiceProvider; class TestFacadesServiceProvider extends ServiceProvider {    public function boot() {       //    }    public function register() {      //可以這么綁定,這需要use App;     //  App::bind('test',function() {     //     return new AppTestTestFacades;     //  });            //也可以這么綁定，推薦。這個test對應(yīng)于Facade的getFacadeAccessor返回值         $this->app->bind("test", function(){             return new MyFoo(); //給這個Facade返回一個代理實例。所有對Facade的調(diào)用都會被轉(zhuǎn)發(fā)到該類對象下。         });    } }

Step 5 ? 在config/app.php注冊ServiceProvider類

Step 6 ? 在config/app.php注冊自定義Facade的別名

使用測試：

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去查看輸出