在一個Bundle裏如何加載服務配置

###1.建立一個自動加載的擴展類 *. 類在DependencyInjection命令空間下(一般文件位置位於DependencyInjection 目錄下) *. 文件的命令是去掉Bundle的名稱的後綴Bundle用Extension來替代(eg AppBundle --> AppExtesion)

該類須要實現ExtensionInterface接口；一般經過繼承 Extension類來實現

// src/Acme/HelloBundle/DependencyInjection/AcmeHelloExtension.php
namespace Acme\HelloBundle\DependencyInjection;

use Symfony\Component\HttpKernel\DependencyInjection\Extension;
use Symfony\Component\DependencyInjection\ContainerBuilder;

class AcmeHelloExtension extends Extension
{
    public function load(array $configs, ContainerBuilder $container)
    {
        // ... you'll load the files here later
    }
}

###2. 手動註冊一個擴展類 若是咱們不遵照上面自動加載的約束；咱們將要手動註冊該擴展類；咱們須要重寫Bundle的getContainerExtension方法；該方法返回咱們的擴展類的實例

use Acme\HelloBundle\DependencyInjection\UnconventionalExtensionClass;

class AcmeHelloBundle extends Bundle
{
    public function getContainerExtension()
    {
        return new CustomerExtension();//自定義的擴展類
    }
}

自定義的擴展類；須要重寫getAlias方法返回DI的別名;一般就是去掉Extension後綴的(eg AcmeHelloExtension-->acme_hello)
class CustomerExtension extends Extension
{
    /**
     * {@inheritdoc}
     * load方法全部和extension相關的配置，服務將要被加載
     *
     */
    public function load(array $configs, ContainerBuilder $container)
    {
        //有 YamlFileLoader, PhpFileLoader,IniFileLoader.
        $loader = new Loader\YamlFileLoader($container, new FileLocator(__DIR__.'/../Resources/config'));
        $loader->load('services.yml');
    }

    public function getAlias()
    {
        return 'acme_hello';
    }
}