Building a Production-Ready REST API Client with Dio
Building a Production-Ready REST API Client with Dio A production API client needs more than dio.get() . A robust client should define: Base configuration Timeouts Authentication Interceptors Error mapping Serialization Cancellation Retry behavior Logging Testability Dio provides features such as global configuration, interceptors, cancellation, uploads/downloads, timeouts, and custom adapters.…
1. Install Dio package by adding it to the pubspec.yaml file with the version 5.11.0. Ensure to verify the latest version before upgrading as package versions may change.
2. Create a separate API client class named ApiClient. Import the Dio library and initialize the Dio instance with the base URL and necessary timeouts and headers, including JSON content type.
3. Implement authentication using an interceptor. Define an AuthInterceptor class that extends Interceptor and inject an asynchronous function getAccessToken to retrieve the token. Use the token when making requests if it exists and is not empty.
4. Implement structured error handling by creating an application-level error class, ApiFailure, and its subclasses for network, unauthorized, server, and unknown failures. Map Dio exceptions to these custom ApiFailure classes to provide more granular error handling.
5. Utilize typed models to represent the API's response data. For instance, if the API returns a User object with id and name fields, create a User class with corresponding properties and a factory constructor to parse JSON data into the model.
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