How to generate a datetime in model using flutter freezed package-CodePudding

I have this freezed part

import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:freezed_annotation/freezed_annotation.dart';
part 'user_model.freezed.dart';
part 'user_model.g.dart';

@freezed
class UserModel with _$UserModel {
  factory UserModel({
    required String id,
    @Default('') String uniqueId,
    @Default(DateTime.now()) DateTime dob,

  }) = _UserModel;

  factory UserModel.fromJson(Map<String, dynamic> json) =>
      _$UserModelFromJson(json);
}

But am not able to generate the required file due to DateTime.now().

if I do something like this:

factory UserModel({
        required String id,
        @Default('') String uniqueId,
        required DateTime dob,
    
      }) = _UserModel;

it will work but I have to manually edit the generated data to this:

dob: (json['dob'] as Timestamp?)?.toDate() ?? DateTime.now()

from

dob: DateTime.parse(json['dob'] as String),

I can't keep manually editing it all time.

Please how do I generate the model class including Datetime.

CodePudding user response：

you need to manually add serialization logic in your freezed model class.

In this specific situation, you need firestore timestamp serialization logic.

Just add

import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:json_annotation/json_annotation.dart';

class TimestampSerializer implements JsonConverter<DateTime, dynamic> {
  const TimestampSerializer();

  @override
  DateTime fromJson(dynamic timestamp) => timestamp.toDate();

  @override
  Timestamp toJson(DateTime date) => Timestamp.fromDate(date);
}

and add TimestampSerializer() annotation for your DateTime property like this.

import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:freezed_annotation/freezed_annotation.dart';
part 'user_model.freezed.dart';
part 'user_model.g.dart';

@freezed
class UserModel with _$UserModel {
  factory UserModel({
    required String id,
    @Default('') String uniqueId,
    @TimestampSerializer() required DateTime dob,

  }) = _UserModel;

  factory UserModel.fromJson(Map<String, dynamic> json) =>
      _$UserModelFromJson(json);
}

and then finally run build runner. You are good to go.

Hope it helps! Happy coding:)