我的应用目前正在为每个 api 响应使用自定义类作为模型。 但我试图改变它，优化一些小东西，所以我试图实现一个类包装器，例如称为 ApiResponse。 但是对于 make fromJson 和 toJson，它的静态调用和方法不能正常工作。
我会展示我正在尝试的东西，例如。 MyModel -> 类响应。 ApiResponse -> 包含内部任何模型类的主类，并且必须将子方法作为其自身的“fromjson/tojson”来调用。 测试 -> 用于测试目的的类，对类的错误注释。
class MyModel {
String id;
String title;
MyModel({this.id, this.title});
factory MyModel.fromJson(Map<String, dynamic> json) {
return MyModel(
id: json["id"],
title: json["title"],
);
}
Map<String, dynamic> toJson() => {
"id": this.id,
"title": this.title,
};
}
class ApiResponse<T> {
bool status;
String message;
T data;
ApiResponse({this.status, this.message, this.data});
factory ApiResponse.fromJson(Map<String, dynamic> json) {
return ApiResponse<T>(
status: json["status"],
message: json["message"],
data: (T).fromJson(json["data"])); // The method 'fromJson' isn't defined for the type 'Type'.
// Try correcting the name to the name of an existing method, or defining a method named 'fromJson'.
}
Map<String, dynamic> toJson() => {
"status": this.status,
"message": this.message,
"data": this.data.toJson(), // The method 'toJson' isn't defined for the type 'Object'.
// Try correcting the name to the name of an existing method, or defining a method named 'toJson'
};
}
class Test {
test() {
ApiResponse apiResponse = ApiResponse<MyModel>();
var json = apiResponse.toJson();
var response = ApiResponse<MyModel>.fromJson(json);
}
}
您不能在 Dart 上调用类型的方法，因为静态方法必须在编译时解析，并且类型直到运行时才具有值。
但是，您可以将解析器回调传递给构造函数并使用每个模型都可以实现的接口（例如
SerializableApiResponseApiResponse<T extends Serializable>TtoJson()这里更新了完整的例子。
class MyModel implements Serializable {
String id;
String title;
MyModel({this.id, this.title});
factory MyModel.fromJson(Map<String, dynamic> json) {
return MyModel(
id: json["id"],
title: json["title"],
);
}
@override
Map<String, dynamic> toJson() => {
"id": this.id,
"title": this.title,
};
}
class ApiResponse<T extends Serializable> {
bool status;
String message;
T data;
ApiResponse({this.status, this.message, this.data});
factory ApiResponse.fromJson(Map<String, dynamic> json, Function(Map<String, dynamic>) create) {
return ApiResponse<T>(
status: json["status"],
message: json["message"],
data: create(json["data"]),
);
}
Map<String, dynamic> toJson() => {
"status": this.status,
"message": this.message,
"data": this.data.toJson(),
};
}
abstract class Serializable {
Map<String, dynamic> toJson();
}
class Test {
test() {
ApiResponse apiResponse = ApiResponse<MyModel>();
var json = apiResponse.toJson();
var response = ApiResponse<MyModel>.fromJson(json, (data) => MyModel.fromJson(data));
}
}
base_response.dart
class BaseResponse {
dynamic message;
bool success;
BaseResponse(
{this.message, this.success});
factory BaseResponse.fromJson(Map<String, dynamic> json) {
return BaseResponse(
success: json["success"],
message: json["message"]);
}
}
list_response.dart
server response for list
{
"data": []
"message": null,
"success": true,
}
@JsonSerializable(genericArgumentFactories: true)
class ListResponse<T> extends BaseResponse {
List<T> data;
ListResponse({
String message,
bool success,
this.data,
}) : super(message: message, success: success);
factory ListResponse.fromJson(Map<String, dynamic> json, Function(Map<String, dynamic>) create) {
var data = List<T>();
json['data'].forEach((v) {
data.add(create(v));
});
return ListResponse<T>(
success: json["success"],
message: json["message"],
data: data);
}
}
single_response.dart
server response for single object
{
"data": {}
"message": null,
"success": true,
}
@JsonSerializable(genericArgumentFactories: true)
class SingleResponse<T> extends BaseResponse {
T data;
SingleResponse({
String message,
bool success,
this.data,
}) : super(message: message, success: success);
factory SingleResponse.fromJson(Map<String, dynamic> json, Function(Map<String, dynamic>) create) {
return SingleResponse<T>(
success: json["success"],
message: json["message"],
data: create(json["data"]));
}
}
data_response.dart
class DataResponse<T> {
Status status;
T res; //dynamic
String loadingMessage;
GeneralError error;
DataResponse.init() : status = Status.Init;
DataResponse.loading({this.loadingMessage}) : status = Status.Loading;
DataResponse.success(this.res) : status = Status.Success;
DataResponse.error(this.error) : status = Status.Error;
@override
String toString() {
return "Status : $status \n Message : $loadingMessage \n Data : $res";
}
}
enum Status {
Init,
Loading,
Success,
Error,
}
或者如果使用 freeezed 那么 data_response 可以是
@freezed
abstract class DataResponse<T> with _$DataResponse<T> {
const factory DataResponse.init() = Init;
const factory DataResponse.loading(loadingMessage) = Loading;
const factory DataResponse.success(T res) = Success<T>;
const factory DataResponse.error(GeneralError error) = Error;
}
用法：（改造库的一部分
@GET(yourEndPoint)
Future<SingleResponse<User>> getUser();
@GET(yourEndPoint)
Future<ListResponse<User>> getUserList();
如果不使用reftofit：
const _extra = <String, dynamic>{};
final queryParameters = <String, dynamic>{};
final _data = <String, dynamic>{};
final _result = await _dio.request<Map<String, dynamic>>('$commentID',
queryParameters: queryParameters,
options: RequestOptions(
method: 'GET',
headers: <String, dynamic>{},
extra: _extra,
baseUrl: baseUrl),
data: _data);
final value = SingleResponse<Comment>.fromJson(
_result.data,
(json) => Comment.fromJson(json),
);
您可以尝试我的方法来应用通用响应：
APIResponse<MyModel>MyModelFuture<User> fetchUser() async {
final client = APIClient();
final result = await client.request<APIResponse<User>>(
manager: APIRoute(APIType.getUser),
create: () => APIResponse<User>(create: () => User())
);
final user = result.response.data; // reponse.data will map with User
if (user != null) {
return user;
}
throw ErrorResponse(message: 'User not found');
}
这是我的源代码： https://github.com/katafo/flutter-generic-api-response
There is another way,
Map<String, dynamic> toJson() => {
"message": message,
"status": status,
"data": _toJson<T>(data),
};
static T _fromJson<T>(Map<String, dynamic> json) {
return ResponseModel.fromJson(json) as T;
}