php 45 lines · 7 steps

Binding a payment gateway in Laravel

A deferred service provider wires an interface to the right implementation based on environment and config.

Explained by highlit

Laravel Intermediate dependency-injection service-container interface-binding deferred-loading configuration

1<?php
2 
3namespace App\Providers;
4 
5use App\Contracts\PaymentGateway;
6use App\Services\Payments\FakePaymentGateway;
7use App\Services\Payments\StripePaymentGateway;
8use Illuminate\Contracts\Support\DeferrableProvider;
9use Illuminate\Support\ServiceProvider;
10use Stripe\StripeClient;
11 
12class PaymentServiceProvider extends ServiceProvider implements DeferrableProvider
13{
14    public function register(): void
15    {
16        $this->app->bind(PaymentGateway::class, function ($app) {
17            $config = $app['config']['services.stripe'];
18 
19            if ($app->environment('testing') || empty($config['secret'])) {
20                return new FakePaymentGateway();
21            }
22 
23            return new StripePaymentGateway(
24                new StripeClient($config['secret']),
25                $config['webhook_secret'] ?? null,
26            );
27        });
28 
29        $this->app->singleton(StripeClient::class, function ($app) {
30            return new StripeClient($app['config']['services.stripe.secret']);
31        });
32 
33        $this->app->when(StripePaymentGateway::class)
34            ->needs('$currency')
35            ->giveConfig('services.stripe.currency', 'usd');
36    }
37 
38    public function provides(): array
39    {
40        return [
41            PaymentGateway::class,
42            StripeClient::class,
43        ];
44    }
45}

01 / 01

STEP 01

Walkthrough

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Three takeaways

1Binding to an interface lets you swap implementations without touching the code that depends on it.
2Resolving the implementation inside a closure defers the decision until the service is actually needed.
3Deferred providers list what they provide so Laravel can skip booting them until something asks.

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