如何映射作为DART中其他模型基础的复杂模型

发布于02月13日

我有一个模型，我希望从HTTP请求中获取响应并将其映射.问题是这个模型有一个可以接受任何属性的属性，但我想正确地映射它.

class BaseResponse<T> {
  final bool error;
  final String? message;
  final T? result;

  const BaseResponse({required this.error, this.message, this.result});

  factory BaseResponse.fromJson(Map<String, dynamic> json) {
    bool error = json['error'];
    String? message = json['message'];
    T? result = json['result'];

    return BaseResponse(error: error, message: message, result: result);
  }
}

我想找出一种方法，可以将JSON中的正确数据映射到Result属性中.结果属性可以是复杂的模型，也可以是像String这样的简单属性.

class SampleModel {
    final String firstName;
    final String lastName;
    final AddressModel address;

    SampleModel({ required this.firstName, required this.lastName, required this.address });
}

class AddressModel {
    final String street;
    final String city;
    // ... more properties

    AddressModel({ required this.street, required this.city, /* More properties here */ });
}

void main() {
    Future<void> getResponse() async {
        Future<http.Response> response = await http.get('https://getsomething.com');

        // Do some checks against response

        BaseResponse<SampleModel> = BaseResponse.fromJson(jsonDecode(response.body) as Map<String, dynamic>);
    }

    getResponse();
}

factory BaseResponse.fromJson(Map<String, dynamic> json, T? Function(Object?) parseResult) { bool error = json['error']; String? message = json['message']; T? result = parseResult(json['result']); return BaseResponse(error: error, message: message, result: result); }

static SampleModel fromJson(Object? result) { if (result case { "firstName": String first, "lastName": String last, "address": Map<String, Object?> addressJson, // .. }) { var address = AddressModel.fromJson(addressJson); if (address != null) { return SampleModel(firstName: first, lastName: last, address: address); } } return null; }

// Do some checks against response BaseResponse<SampleModel> model = BaseResponse.fromJson( jsonDecode(response.body) as Map<String, dynamic>, SampleModel.fromJson); // <-- added here.

class BaseResponse<T extends Object> { ... BaseResponse.fromJson(Map<String, dynamic> json, T? result) : this(error: json['error'], message: json['message'], result: result); } class SampleModel { static SampleModel? fromJson(Map<String, dynamic> json) { // Parse firstName/lastName/etc as above. return sample; } static BaseResponse<SampleModel> baseFromJson(Map<String, dynamic> json) { SampleModel? result = fromJson(json); return BaseResponse<SampleModel>(json, result); } }

如何映射作为DART中其他模型基础的复杂模型

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