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, {String baseUrl}) = _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
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](/user/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](/user/GET)("/tasks/{id}")
  Future<Task> getTask([@Path](/user/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);
@POST(“http://httpbin.org/post”)
Future<void> createNewTaskFromFile(@Part() File file);
@POST(“http://httpbin.org/post”)
@FormUrlEncoded()
Future<String> postUrlEncodedFormData(@Field() String hello);

Get orignal HTTP reponse

  [@GET](/user/GET)("/tasks/{id}")
  Future<HttpResponse<Task>> getTask([@Path](/user/Path)("id") String id)
@GET("/tasks")
Future<HttpResponse<List<Task>>>> getTasks()

HTTP Header

• Add a HTTP header from the parameter of the method

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

• Add staitc HTTP headers

  	[@GET](/user/GET)("/tasks")
  	[@Headers](/user/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:
    }
  });
}