Service Providers

• Introduction
• Create Service Provider
• Dependency Relationship
• Runners

Introduction

The most important thing in the kernel boot operation is to load the ServiceProvider. All ServiceProvider under the application are configured in the bootstrap/providers.go file.

First, the kernel will call the Register method of all service providers. After all service providers have been registered, the kernel will call the Boot method of all ServiceProvider again.

The ServiceProvider is the key to the life cycle of Goravel. They enable the framework to contain various components, such as routing, database, queue, cache, etc.

Create Service Provider

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, use the Boot method for that.

./artisan make:provider YourServiceProviderName

The Artisan CLI can generate a new provider via the make:provider command. The new service provider will be registered automatically in the bootstrap/providers.go::Providers() function and the function will be called by WithProviders.

func Boot() contractsfoundation.Application {
	return foundation.Setup().
		WithProvders(Providers).
		WithConfig(config.Boot).
		Create()
}

Dependency Relationship

ServiceProvider provides an optional method Relationship() binding.Relationship, used to declare the dependency relationship, the ServiceProvider that sets this method will not depend on the registration order, and the ServiceProvider that does not set it will be registered last, for example:

type ServiceProvider struct {}

func (r *ServiceProvider) Relationship() binding.Relationship {
	return binding.Relationship{
		Bindings: []string{
			"custom",
		},
		Dependencies: []string{
			binding.Config,
		},
		ProvideFor: []string{
			binding.Cache,
		},
	}
}

func (r *ServiceProvider) Register(app foundation.Application) {
	app.Singleton("custom", func(app foundation.Application) (any, error) {
		return New()
	})
}

func (r *ServiceProvider) Boot(app foundation.Application) {}

Runners

The ServiceProvider can also implement the Runners interface to run some code when the application starts. It's usually used to start/shutdown the service which is defined in the ServiceProvider. For example: Route, Schedule, Queue, etc. You don't need to start/shutdown these services with Runners in the main.go anymore, Goravel will take care of it.

A Runner contains three methods: ShouldRun(), Run(), and Shutdown().

type Runner interface {
	// ShouldRun determines whether the runner should be executed.
	ShouldRun() bool
	// Run starts the runner.
	Run() error
	// Shutdown gracefully stops the runner.
	Shutdown() error
}

There is an example of a RouteRunner defined in the ServiceProvider to start and shutdown the Route service.

type ServiceProvider struct {}

func (r *ServiceProvider) Register(app foundation.Application) {}

func (r *ServiceProvider) Boot(app foundation.Application) {}

func (r *ServiceProvider) Runners(app foundation.Application) []foundation.Runner {
	return []foundation.Runner{NewRouteRunner(app.MakeConfig(), app.MakeRoute())}
}

package route

import (
	"github.com/goravel/framework/contracts/config"
	"github.com/goravel/framework/contracts/route"
)

type RouteRunner struct {
	config config.Config
	route  route.Route
}

func NewRouteRunner(config config.Config, route route.Route) *RouteRunner {
	return &RouteRunner{
		config: config,
		route:  route,
	}
}

func (r *RouteRunner) ShouldRun() bool {
	return r.route != nil && r.config.GetString("http.default") != ""
}

func (r *RouteRunner) Run() error {
	return r.route.Run()
}

func (r *RouteRunner) Shutdown() error {
	return r.route.Shutdown()
}

You can register your own Runner in the bootstrap/app.go::WithRunners function to run some code when the application starts.

func Boot() contractsfoundation.Application {
	return foundation.Setup().
		WithConfig(config.Boot).
		WithRunners(func() []foundation.Runner{
			return []foundation.Runner{
				NewYourCustomRunner(),
			}
		}).
		Create()
}