How do you load array and object from Cloud Firestore in Flutter

Question

I have a class that has several embedded arrays as well as a couple of objects. I\'m using Flutter and can\'t figure out how to read/write to Cloud Firestore.

I can r

Answer 1

load the list from the array and let the framework take care of type casting.

an object is simply a map, like you wrote in your Json. I also use named constructor. ((still learning and dont know how to use the static constructor @ganapat mentioned))

here´s the working code. I kept firebase auth out and used the StreamBuilder widget.

import 'dart:async';
import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:flutter/material.dart';
import 'model/firebase_auth_service.dart';

void main() async {
  runApp(new MyApp());
}

class MyApp extends StatelessWidget {
  final firebaseAuth = new FirebaseAuthService();

  MyApp() {
    firebaseAuth.anonymousLogin();
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
        home: Scaffold(
            body: Center(
                child: FlatButton(
      color: Colors.amber,
      child: Column(
        mainAxisSize: MainAxisSize.min,
        children: [
          Text("get Game Record"),
          StreamBuilder(
            stream: getGame(),
            builder: (BuildContext c, AsyncSnapshot data) {
              if (data?.data == null) return Text("Error");

              GameRecord r = data.data;

              return Text("${r.creationTimestamp} + ${r.name}");
            },
          ),
        ],
      ),
      onPressed: () {
        getGame();
      },
    ))));
  }
}

Stream getGame() {
  return Firestore.instance
      .collection("games")
      .document("zZJKQOuuoYVgsyhJJAgc")
      .get()
      .then((snapshot) {
    try {
      return GameRecord.fromSnapshot(snapshot);
    } catch (e) {
      print(e);
      return null;
    }
  }).asStream();
}

class GameReview {
  String name;
  int howPopular;
  List reviewers;

  GameReview.fromMap(Map data)
      : name = data["name"],
        howPopular = data["howPopular"],
        reviewers = List.from(data['reviewers']);
}

class GameRecord {
  // Header members
  String documentID;
  String name;
  int creationTimestamp;
  List ratings = new List();
  List players = new List();
  GameReview gameReview;

  GameRecord.fromSnapshot(DocumentSnapshot snapshot)
      : documentID = snapshot.documentID,
        name = snapshot['name'],
        creationTimestamp = snapshot['creationTimestamp'],
        ratings = List.from(snapshot['ratings']),
        players = List.from(snapshot['players']),
        gameReview = GameReview.fromMap(snapshot['gameReview']);
}

snapshot['itemCount'] is an array of objects. map each item in that array to an ItemCount object and return as a List:

    itemCounts = snapshot['itemCount'].map((item) {
      return ItemCount.fromMap(item);
    }).toList();