Retrofit For Dart #

retrofit.dart is a type conversion dio client generator using source_gen and inspired by Chopper and Retrofit.

Usage #

Generator #

Add the generator to your dev dependencies

dependencies:
  retrofit: any
  logger: any  #for logging purpose

dev_dependencies:
  retrofit_generator: any
  build_runner: any

Define and Generate your API #

import 'package:json_annotation/json_annotation.dart';
import 'package:retrofit/retrofit.dart';
import 'package:dio/dio.dart';

part 'example.g.dart';

@RestApi(baseUrl: "https://5d42a6e2bc64f90014a56ca0.mockapi.io/api/v1/")
abstract class RestClient {
  factory RestClient(Dio dio) = _RestClient;

  @GET("/tasks")
  Future<List<Task>> getTasks();
}

@JsonSerializable()
class Task {
  String id;
  String name;
  String avatar;
  String createdAt;

  Task({this.id, this.name, this.avatar, this.createdAt});

  factory Task.fromJson(Map<String, dynamic> json) => _$TaskFromJson(json);
  Map<String, dynamic> toJson() => _$TaskToJson(this);
}

then run the generator

# dart
pub run build_runner build

# flutter	
flutter pub run build_runner build

Use it #

import 'package:logger/logger.dart';
import 'package:retrofit_example/example.dart';
import 'package:dio/dio.dart';

final logger = Logger();
void main(List<String> args) {
  final dio = Dio();   // Provide a dio instance
  dio.options.headers["Demo-Header"] = "demo header";   // config your dio headers globally
  dio.options.headers["Content-Type"] = "application/json";
  final client = RestClient(dio);
  
  client.getTasks().then((it) => logger.i(it));

More #

Type Conversion #

Before you use the type conversion, please make sure that a factory Task.fromJson(Map<String, dynamic> json) must be provided for each model class. json_serializable is the recommanded to be used as the serialization tool.

...
@GET("/tasks")
  Future<List<Task>> getTasks();
}

@JsonSerializable()
class Task {
  String name;
  Task({this.name});
  factory Task.fromJson(Map<String, dynamic> json) => _$TaskFromJson(json);
}

HTTP Methods #

The HTTP methods in the below sample are supported.

  @GET("/tasks/{id}")
  Future<Task> getTask(@Path("id") String id);

  @PATCH("/tasks/{id}")
  Future<Task> updateTaskPart(
      @Path() String id, @Body() Map<String, dynamic> map);

  @PUT("/tasks/{id}")
  Future<Task> updateTask(@Path() String id, @Body() Task task);

  @DELETE("/tasks/{id}")
  Future<void> deleteTask(@Path() String id);

  @POST("/tasks")
  Future<Task> createTask(@Body() Task task);

HTTP Header #

• Add a HTTP header from the parameter of the method

    @GET("/tasks")
    Future<Task> getTasks(@Header("Content-Type") String contentType );
  

• Add staitc HTTP headers

    @GET("/tasks")
    @Headers(<String, dynamic>{
        "Content-Type" : "application/json",
        "Custom-Header" : "Your header"
    })
    Future<Task> getTasks();
  

Error Handling #

catchError(Object) should be used for capturing the exception and failed response. You can get the detailed response info from DioError.response.

 client.getTask("2").then((it){
   logger.i(it);
 }).catchError((Object obj) {
    // non-200 error goes here.
    switch (obj.runtimeType) {
      case DioError:
        // Here's the sample to get the failed response error code and message
        final res = (obj as DioError).response;
        logger.e("Got error : ${res.statusCode} -> ${res.statusMessage}");
        break;
      default:
    }
  });

}