Service Provider

Introduction of Service Provider

Service Provider is an useful way to encapsulate logic of creating objects and services. For example, a mailer library, custom listeners or 3rd tools. Some libraries need a bootstrapping process, we should put this process in Service Provider.

Service Provider will working with IoC Container, we'll implement the \Windwalker\DI\ServiceProviderInterface and write all our logic in register() method and set our service objects into container.

Basic Provider Example

Take a look of this example code, in a original way, if we have a MongoDB driver to bootstrap, we'll write an bootstrap file.

Original Way

// import.mongodb.php

$conn = new MongoDBConnection($config['database']['mongodb']);

return $conn;

And include this file:

$mongo = include_once 'import.mongodb.php';

Windwalker Way

In Windwalker, we can create a MongoDBServiceProvider, and set MongoDB connection to Container.

use Windwalker\DI\Container;
use Windwalker\DI\ServiceProviderInterface;

class MongoDBServiceProvider implements ServiceProviderInterface
{
    public function register(Container $container)
    {
        $container->share('mongo.db', function (Container $container)
        {
            $config = $container->get('config');

            return new MongoDBConnection($config->get('database.mongodb'));
        });
    }
}

Register this provider to container:

$container->registerServiceProvider(new MongoDBServiceProvider);

Then get this object from Container, this process will be lazy loading, MongoDB will connected after your first get it:

$mongo = $container->get('mongo.db');

// OR

$mongo = Ioc::get('mongo.db');

About how to use IoC (DI) Container, see: IoC Container

Registering Providers

All Service Providers are registered in Application::loadProviders(). For example, open /src/Windwalker/Web/Application.php, you will see loadProviders(), there is an array $providers here, help ue override default providers, now we add our Service Provider here:

public function loadProviders()
{
    $providers = parent::loadProviders();

    // Default providers ...

    /*
     * Custom Providers:
     * -----------------------------------------
     * You can add your own providers here. If you installed a 3rd party packages from composer,
     * but this package need some init logic, create a service provider to do this and register it here.
     */

    // Custom Providers here...
    $providers['mongodb'] = new MongoDBServiceProvider;

    return $providers;
}

There are 3 positions in default Windwalker Application we can add providers:

• src/Windwalker/Web/Application.php
• src/Windwalker/Console/Application/php
• src/Windwalker.php

If you want to use service for Web application, add provider in Web\Application, else you can add provider in Console\Application for console use, or add it in Windwalker.php for both.

If you found a typo or error, please help us improve this document.