Service Providers

Introduction

Service providers are the central place of all WpMVC application bootstrapping. Your own application, as well as all of WpMVC’s core services, are bootstrapped via service providers.

But, what do we mean by “bootstrapped”? In general, we mean registering things, including registering service container bindings and WordPress hooks. Service providers are the central place to configure your application.

WpMVC uses several service providers internally to bootstrap its core services. Many of these providers are essential for the framework’s operation.

All user-defined service providers are registered in the config/app.php file. In the following documentation, you will learn how to write your own service providers and register them with your WpMVC application.

Writing Service Providers

All service providers extend the MyPluginNamespace\WpMVC\Contracts\Provider class. Most service providers contain a register and a boot method. Within the register method, you should only bind things into the service container. You should never attempt to register any event listeners, routes, or any other piece of functionality within the register method.

The Artisan CLI can generate a new provider via the make:provider command:


php artisan make:provider RiakServiceProvider

The Register Method

As mentioned previously, within the register method, you should only bind things into the service container. You should never attempt to register any WordPress hooks, routes, or any other piece of functionality within the register method. Otherwise, you may accidentally use a service that is provided by a service provider which has not loaded yet.

Let’s take a look at a basic service provider. Within any of your service provider methods, you always have access to the $this->app property which provides access to the service container:


<?php
 
namespace MyPluginNamespace\App\Providers;
 
defined( "ABSPATH" ) || exit;
 
use MyPluginNamespace\WpMVC\Contracts\Provider;
use MyPluginNamespace\Services\Riak\Connection;
use MyPluginNamespace\WpMVC\App;
 
class RiakServiceProvider extends Provider
{
    /**
     * Register any application services.
     *
     * @return void
     */
    public function register() {
        $this->app->singleton( Connection::class, function ( $app ) {
            return new Connection( App::get_config()->get( 'riak' ) );
        } );
    }
}

This service provider only defines a register method, and uses that method to define an implementation of MyPluginNamespace\Services\Riak\Connection in the service container. If you’re not yet familiar with WpMVC’s service container, check out its documentation.

The Boot Method

So, what if we need to register a WordPress action or filter within our service provider? This should be done within the boot method. This method is called after all other service providers have been registered, meaning you have access to all other services that have been registered by the framework:


<?php
 
namespace MyPluginNamespace\App\Providers;
 
defined( "ABSPATH" ) || exit;
 
use MyPluginNamespace\WpMVC\Contracts\Provider;
 
class HookServiceProvider extends Provider
{
    /**
     * Bootstrap any application services.
     *
     * @return void
     */
    public function boot() {
        add_action( 'wp_head', [ $this, 'add_analytics_script' ] );
        
        add_filter( 'the_content', function ( $content ) {
            return $content . '<p>Powered by WpMVC</p>';
        } );
    }
 
    /**
     * Add analytics script to the head.
     *
     * @return void
     */
    public function add_analytics_script() {
        echo '<!-- Analytics -->';
    }
}

WordPress Hooks and Shortcode Examples

The boot method is also the perfect place to register your WordPress-specific logic such as custom post types, shortcodes, and AJAX handlers. This ensures that the underlying services they might depend on are already registered in the container.


<?php
 
namespace MyPluginNamespace\App\Providers;
 
defined( "ABSPATH" ) || exit;
 
use MyPluginNamespace\WpMVC\Contracts\Provider;
 
class DiscoveryServiceProvider extends Provider
{
    /**
     * Bootstrap any application services.
     *
     * @return void
     */
    public function boot() {
        // Registering a Custom Post Type
        add_action( 'init', [ $this, 'register_custom_post_types' ] );
 
        // Registering a Shortcode
        add_shortcode( 'my_plugin_data', [ $this, 'render_shortcode' ] );
 
        // Registering an AJAX Handler
        add_action( 'wp_ajax_my_action', [ $this, 'handle_ajax' ] );
        add_action( 'wp_ajax_nopriv_my_action', [ $this, 'handle_ajax' ] );
    }
 
    /**
     * Register custom post types.
     * 
     * @return void
     */
    public function register_custom_post_types() {
        register_post_type( 'book', [
            'public' => true,
            'label'  => 'Books',
        ] );
    }
 
    /**
     * Render the shortcode.
     * 
     * @param  array  $atts
     * @return string
     */
    public function render_shortcode( $atts ) {
        return '<div>Shortcode Content</div>';
    }
 
    /**
     * Handle AJAX request.
     * 
     * @return void
     */
    public function handle_ajax() {
        wp_send_json_success( [ 'message' => 'AJAX Success' ] );
    }
}

Boot Method Dependency Injection

You may type-hint dependencies for your service provider’s boot method. The service container will automatically inject any dependencies you need:


use MyPluginNamespace\Services\SettingsService;
 
/**
 * Bootstrap any application services.
 *
 * @param  SettingsService  $settings
 * @return void
 */
public function boot( SettingsService $settings ) {
    if ( $settings->is_enabled( 'analytics' ) ) {
        add_action( 'wp_footer', [ $this, 'inject_footer_script' ] );
    }
}

Registering Providers

All service providers are registered in the config/app.php configuration file. This file contains a providers array where you can list the class names of your service providers.

In WpMVC, you can distinguish between global providers and providers that should only load in the WordPress Admin environment:


<?php
 
defined( "ABSPATH" ) || exit;
 
use MyPluginNamespace\App\Providers\RiakServiceProvider;
use MyPluginNamespace\App\Providers\HookServiceProvider;
use MyPluginNamespace\App\Providers\Admin\MenuServiceProvider;
 
return [
    /**
     * Core application and plugin-wide providers.
     */
    'providers' => [
        RiakServiceProvider::class,
        HookServiceProvider::class,
    ],
 
    /**
     * Providers loaded only within the WordPress Admin environment.
     */
    'admin_providers' => [
        MenuServiceProvider::class,
    ],
];

When you invoke the make:provider Artisan command, you should manually add the generated provider to this configuration file. WpMVC will automatically instantiate each provider and execute the register and boot methods in the order they are listed.