I study flutter. I'm beginner and currently started to learn CRUD with firebase.
I study from this great gentleman's code
https://github.com/mohamedHassanKa/ProductAppCourse
This is my first time to connect firebase. Am I connecting firebase sucesfully? I got these error. Could someone teach me how to correct code please?
CRUDEModel.dart
import 'dart:async';
import 'package:flutter/material.dart';
import '../../locator.dart';
import '../services/api.dart';
import '../models/productModel.dart';
import 'package:cloud_firestore/cloud_firestore.dart';
class CRUDModel extends ChangeNotifier {
Api _api = locator<Api>();
List<Product> products;
Future<List<Product>> fetchProducts() async {
var result = await _api.getDataCollection();
products = result.documents
.map((doc) => Product.fromMap(doc.data, doc.documentID))
.toList();
return products;
}
Stream<QuerySnapshot> fetchProductsAsStream() {
return _api.streamDataCollection();
}
Future<Product> getProductById(String id) async {
var doc = await _api.getDocumentById(id);
return Product.fromMap(doc.data, doc.documentID) ;
}
Future removeProduct(String id) async{
await _api.removeDocument(id) ;
return ;
}
Future updateProduct(Product data,String id) async{
await _api.updateDocument(data.toJson(), id) ;
return ;
}
Future addProduct(Product data) async{
var result = await _api.addDocument(data.toJson()) ;
return ;
}
Error
lib/core/viewmodels/CRUDModel.dart:16:23: Error: The getter 'documents' isn't defined for the class 'QuerySnapshot<Object>'.
- 'QuerySnapshot' is from 'package:cloud_firestore/cloud_firestore.dart' ('../../Documents/flutter_windows_3.3.4-stable/flutter/.pub-cache/hosted/pub.dartlang.org/cloud_firestore-4.1.0/lib/cloud_firestore.dart').
- 'Object' is from 'dart:core'.
Try correcting the name to the name of an existing getter, or defining a getter or field named 'documents'.
products = result.documents
^^^^^^^^^
lib/core/viewmodels/CRUDModel.dart:28:43: Error: The getter 'documentID' isn't defined for the class 'DocumentSnapshot<Object>'.
- 'DocumentSnapshot' is from 'package:cloud_firestore/cloud_firestore.dart' ('../../Documents/flutter_windows_3.3.4-stable/flutter/.pub-cache/hosted/pub.dartlang.org/cloud_firestore-4.1.0/lib/cloud_firestore.dart').
- 'Object' is from 'dart:core'.
Try correcting the name to the name of an existing getter, or defining a getter or field named 'documentID'.
return Product.fromMap(doc.data, doc.documentID) ;
^^^^^^^^^^
lib/core/viewmodels/CRUDModel.dart:28:33: Error: The argument type 'Object Function()' can't be assigned to the parameter type 'Map<dynamic, dynamic>'.
- 'Object' is from 'dart:core'.
- 'Map' is from 'dart:core'.
return Product.fromMap(doc.data, doc.documentID) ;
^
lib/core/services/api.dart:5:9: Error: Type 'Firestore' not found.
final Firestore _db = Firestore.instance;
^^^^^^^^^
lib/core/services/api.dart:5:9: Error: 'Firestore' isn't a type.
final Firestore _db = Firestore.instance;
^^^^^^^^^
lib/core/services/api.dart:5:25: Error: Undefined name 'Firestore'.
final Firestore _db = Firestore.instance;
^^^^^^^^^
CodePudding user response：
since you said you're new, then you should know that this repository is been made 3 years ago, and a lot of updates happened to the Firebase SDK for Flutter.
with the new versions of Firebase services, exactly in the Firestore, to get its instance inside your project:
Firestore.instance // old
FirebaseFirestore.instance // new
The documents property is replaced with docs, so you need to use this:
result.documents // old - not working
result.docs // new - will return a List<DocumentSnapshot>
to get the Map<String, dynamic> data of a specific document, you need:
doc.data // old
doc.data() as Map<String, dynamic> new
to get the id of a document you should use:
doc.documentId // old
doc.id // new
so basically your code with new migrations should be similar to this:
class CRUDModel extends ChangeNotifier {
Api _api = locator<Api>();
List<Product> products;
Future<List<Product>> fetchProducts() async {
QuerySnapshot result = await _api.getDataCollection();
products = result.docs
.map((doc) => Product.fromMap(doc.data() as Map<String, dynamic>, doc.id))
.toList();
return products;
}
Stream<QuerySnapshot> fetchProductsAsStream() {
return _api.streamDataCollection();
}
Future<Product> getProductById(String id) async {
DocumentSnapshot doc = await _api.getDocumentById(id);
return Product.fromMap(doc.data() as Map<String, dynamic>, doc.id) ;
}
Future removeProduct(String id) async{
await _api.removeDocument(id) ;
return ;
}
Future updateProduct(Product data,String id) async{
await _api.updateDocument(data.toJson(), id) ;
return ;
}
Future addProduct(Product data) async{
var result = await _api.addDocument(data.toJson()) ;
return ;
}}
I assume that those changes are not enough, and you need to migrate with the new terms/notations of Firebase SDK.
I would say that you need to stop following with the old repository ( no offense to its owner ), and look for a new project, or just follow first and read the official documentation of Firebase.
check this:
https://firebase.flutter.dev/docs/firestore/overview