🌐 HTTP Client

The project uses Dio as the primary HTTP client for all API interactions. It is wrapped and initialized through a custom HttpClient class for consistent configuration and centralized request handling.

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📁 File: lib/_core/http_client.dart

class HttpClient {
  static Future<void> init() async {
    Dio dio = Dio(BaseOptions(baseUrl: Constants.apiBaseUrl));
    ...
    di.registerLazySingleton(() => dio);
  }
}

This class configures and registers Dio with necessary interceptors and a base URL, and integrates it into the app’s dependency injection container (di).

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🔧 Initialization

The HttpClient.init() method is called in bootstrap.dart during app startup.

It does the following:

1. Sets a base URL from Constants.apiBaseUrl
2. Adds interceptors for:
   • Automatically attaching authorization tokens
   • Logging requests
   • Handling response and error logic
3. Registers Dio in DI so it can be used anywhere in the app via di()

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🛡️ Interceptors

🔑 Request Interceptor

Automatically attaches the bearer token from Hive storage (if present):

final tokenBox = await Hive.openLazyBox(Constants.tokenBoxName);
final token = await tokenBox.get(Constants.cachedTokenRef);
options.headers['authorization'] = "Bearer $token";

Also logs the outgoing request:

debugPrint("request: ${options.uri}");

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✅ Response Interceptor

Only passes successful responses (status code 2xx). Others are converted to a ServerException (placeholder for now):

if (response.statusCode! >= 200 || response.statusCode! < 300) {
  return handler.next(response);
} else {
  response = ServerException() as Response;
  return handler.next(response);
}

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❌ Error Interceptor

Logs the error and continues the chain:

print('onError: => $e');

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🧑‍💻 Accessing Dio Anywhere

Because Dio is registered in the DI container, you can retrieve it from anywhere using:

final dio = di<Dio>();

⸻

📦 Related Files

File	Purpose
constants.dart	Stores the base URL and Hive box/token keys
di.dart	Registers Dio as a lazy singleton
bootstrap.dart	Calls HttpClient.init() during app startup
error/exceptions.dart	Contains custom exception classes like ServerException

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🧪 Testing Tips

• You can replace the real Dio instance in tests with a mock:

  di.unregister<Dio>();
  di.registerLazySingleton<Dio>(() => MockDio());
  

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🚧 Improvements To Consider

• Use pretty_dio_logger for better request/response logs during development.