Plugin Laravel Package

Getting Started

Minimal Setup

1. Installation Add the package via Composer (note: this is for Guzzle 3, which is outdated; ensure compatibility with your Laravel version):

   composer require guzzle/plugin:^3.0
   

   Check Laravel's Guzzle HTTP client version (vendor/guzzlehttp/guzzle) to confirm compatibility.

2. Basic Usage Register a plugin with Guzzle’s client:

   use Guzzle\Plugin\PluginInterface;
   use Guzzle\Plugin\BeforePluginInterface;
   use Guzzle\Http\Message\RequestInterface;
   
   $client = new \Guzzle\Http\Client();
   $client->addSubscriber(new class implements BeforePluginInterface {
       public function before(RequestInterface $request) {
           // Modify request (e.g., add headers)
           $request->getHeaders()->add('X-Custom-Header', 'value');
       }
   });
   

3. First Use Case Use a plugin to log requests/responses for debugging:

   $client->addSubscriber(new \Guzzle\Plugin\Log\LogPlugin());
   

Implementation Patterns

Common Workflows

1. Request/Response Modification Use BeforePluginInterface/AfterPluginInterface to intercept and alter requests/responses:

   $client->addSubscriber(new class implements AfterPluginInterface {
       public function after($event, $request) {
           if ($event['result'] instanceof \Guzzle\Http\Message\Response) {
               $response = $event['result'];
               // Parse JSON response
               $data = json_decode($response->getBody(), true);
               // Modify data before returning
           }
       }
   });
   

2. Middleware-Like Behavior Chain plugins for layered functionality (e.g., auth + caching):

   $client->addSubscriber(new AuthPlugin());
   $client->addSubscriber(new CachePlugin());
   

3. Laravel Integration Extend Laravel’s HTTP client (app/Http/Client.php):

   $client = app('http_client');
   $client->getClient()->addSubscriber(new CustomPlugin());
   

Integration Tips

• Dependency Injection: Bind plugins to Laravel’s service container for reuse:

  $this->app->singleton('custom.plugin', function () {
      return new CustomPlugin();
  });
  

• Configuration: Store plugin settings in config/services.php:

  'plugins' => [
      'auth' => [
          'token' => env('API_TOKEN'),
      ],
  ],
  

• Testing: Mock plugins in PHPUnit:

  $mockPlugin = $this->getMockBuilder(CustomPlugin::class)
      ->disableOriginalConstructor()
      ->getMock();
  $client->getClient()->addSubscriber($mockPlugin);
  

Gotchas and Tips

Pitfalls

1. Guzzle 3 Deprecation

   • This package is for Guzzle 3, which is unsupported (Laravel uses Guzzle 6/7).
   • Workaround: Use guzzlehttp/guzzle plugins (e.g., guzzlehttp/middleware) instead.

2. Plugin Order Matters

   • Plugins execute in registration order. Use AfterPluginInterface carefully to avoid race conditions.

3. Memory Leaks

   • Avoid storing large data in plugins (e.g., caching responses globally). Use Laravel’s cache instead.

Debugging

• Log Events: Use Guzzle\Plugin\Log\LogPlugin to inspect request/response cycles:

  $client->addSubscriber(new \Guzzle\Plugin\Log\LogPlugin([
      'log' => \Monolog\Logger::getInstance('guzzle'),
  ]));
  

• Disable Plugins Temporarily: Comment out plugin registrations to isolate issues.

Extension Points

1. Custom Events Extend Guzzle\Plugin\Event for domain-specific logic:

   class CustomEvent extends \Guzzle\Plugin\Event {
       public function __construct($request, $response, $data) {
           parent::__construct($request, $response);
           $this->data = $data;
       }
   }
   

2. Plugin Composition Combine plugins into a single subscriber for cleaner code:

   $client->addSubscriber(new class implements SubscriberInterface {
       public function handle($event) {
           (new AuthPlugin())->handle($event);
           (new CachePlugin())->handle($event);
       }
   });
   

3. Laravel Events Trigger Laravel events from plugins:

   event(new RequestHandled($request, $response));