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 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'],
];
在我们自定义的接口实现时，我们可以在ServiceProvider中使用进行绑定:
$this->app->bind('AppContractsEventPusher', 'AppServicesPusherEventPusher');
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 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 IlluminateSupportFacadesFacade 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 TestFacadesServiceProvider的ServiceProvider ,使用如下命令即可:
php artisan make:provider TestFacadesServiceProvider
Step 2 − 创建一个底层代理类，命名为“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 − 创建一个 Facade 类 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 −创建一个ServiceProviders类，名为“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() {
//可以这么绑定,这需要use App;
// App::bind('test',function() {
// return new AppTestTestFacades;
// });
//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ServiceProvider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：
