firebase - 有没有办法在 Flutter 上为 firestore 数据库生成模型类？

Question

我目前正在手动执行此过程。这是一个示例数据类。有没有办法自动生成？

class RideModel {
  final String docId;
  final bool hasRequest;
  final String rideCollectionId;
  final String vehicleTypeId;
  final double corporationRate;
  final double driverRate;
  final double driverInsurance;
  final double passengerInsurance;
  final List startUpCharge;
  final double waitingCharge;
  final double normalCharge;

  RideModel({this.docId, this.hasRequest, this.rideCollectionId,this.vehicleTypeId, this.corporationRate, this.driverRate, this.driverInsurance, this.passengerInsurance, this.startUpCharge, this.waitingCharge, this.normalCharge});

  factory RideModel.fromFirestore(DocumentSnapshot doc) {
    var data = doc.data;

    return RideModel(
        docId: data['docId'],
        hasRequest: data['hasRequest'],
        rideCollectionId: data['rideCollectionId'],
        vehicleTypeId: data['tripDetails']['vehicleType']['vehicleTypeId'],
        corporationRate: data['tripDetails']['vehicleType']['corporation'].toDouble()??0.0,
        driverRate: data['tripDetails']['vehicleType']['driver'].toDouble()??0.0,
        driverInsurance: data['tripDetails']['vehicleType']['driverInsurance'].toDouble()??0.0,
        passengerInsurance: data['tripDetails']['vehicleType']['passengerInsurance'].toDouble()??0.0,
        normalCharge: data['tripDetails']['vehicleType']['normalCharge'].toDouble()??0.0,
        startUpCharge: data['tripDetails']['vehicleType']['startUpCharge']??[],
        waitingCharge: data['tripDetails']['vehicleType']['waitingCharge'].toDouble()??0.0);
  }
}

Answer 1

正如@Alex Sunder Singh 在评论中以及对此 Community post 的其中一个答案中提到的那样，您可以使用 JsonSerializable()去做吧。

为了使用它，您必须在 pubspec.yaml 上设置这些依赖项

dependencies:
  # Your other regular dependencies here
  json_annotation: <latest_version>

dev_dependencies:
  # Your other dev_dependencies here
  build_runner: <latest_version>
  json_serializable: <latest_version>

然后，添加 @JsonSerializable()给你的类(class)注解以及将包导入你的类(class)，它看起来像这样

import 'package:json_annotation/json_annotation.dart';

@JsonSerializable()
class RideModel {
  final String docId;
  final bool hasRequest;
  final String rideCollectionId;
  final String vehicleTypeId;
  final double corporationRate;
  final double driverRate;
  final double driverInsurance;
  final double passengerInsurance;
  final List startUpCharge;
  final double waitingCharge;
  final double normalCharge;

  RideModel(this.docId, this.hasRequest, this.rideCollectionId,this.vehicleTypeId, this.corporationRate, this.driverRate, this.driverInsurance, this.passengerInsurance, this.startUpCharge, this.waitingCharge, this.normalCharge);

  factory RideModel.fromJson(Map<String, dynamic> json) => _$RideModelFromJson(json);

  Map<String, dynamic> toJson() => _$RideModelToJson(this);
}

注意:使用 @JsonSerializable(explicitToJson: true)如果您希望将所有非原始对象描述为 json 而不是“对象实例”

最后，通过从终端运行代码生成实用程序来生成 JSON 序列化代码

flutter packages pub run build_runner build

这样你就可以使用 toJson()将数据映射到您的对象和 fromJson()将您的对象作为数据发送。

希望这可以帮助。