Class 'QueryDocumentSnapshot' has no instance method '[]'. Receiver: Instance of 'QueryDocumentSnapshot' Tried calling: [] ("name")

user_14100986 0
Viewed 5642

I'm trying to retrieve those both values from FireStore

lastname "test" (string) name "Carlos" (String)

However I'm getting this error

 *Another exception was thrown: NoSuchMethodError: Class 'QueryDocumentSnapshot' has no instance method '[]'.
 ═ Exception caught by widgets library ═
 The following NoSuchMethodError was thrown building StreamBuilder<QuerySnapshot> (dirty, state:
_StreamBuilderBaseState<QuerySnapshot, AsyncSnapshot<QuerySnapshot>>#e1fff):
 
Class 'QueryDocumentSnapshot' has no instance method '[]'.
 
 Receiver: Instance of 'QueryDocumentSnapshot'
 
 Tried calling:[] ("name")

Here's my code:

import 'package:flutter/material.dart';
import 'package:cloud_firestore/cloud_firestore.dart';

class HomePage extends StatelessWidget{

 List<Widget> makeListWiget(AsyncSnapshot snapshot){
   return snapshot.data.documents.map<Widget>((document){
     return ListTile(
       title: Text(document["name"]),
       subtitle: Text(document["lastname"]),

     );
   }).toList();

 }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
  appBar: AppBar(
    title: Text('Área do Cliente'),

  ),
    body: Container(
    child: StreamBuilder (
      stream: FirebaseFirestore.instance.collection("users").snapshots(),
      builder: (context, snapshot){
        return ListView(
          children: makeListWiget(snapshot),


        );
      }
   )

   )
   );

 }

}
google-cloud-firestore firebase flutter
2 Answers

From cloud_firestore: ^0.14.0+2 version, so many methods and fields have been changed.

Need to use get() method for accessing particular field of a doucment like this document.get('user_name') instead of document['user_name']

So you have to access all fields as follows:
document.get('user_name')
document.get('user_mobile')
document.get('user_address')

And also other methods like setData() as set(), updateData() as update().

Please check documention https://pub.dev/packages/cloud_firestore/changelog

user_123425540

The object that you are trying to access with document["name"] is not valid as the object is of instance QueryDocumentSnapshot and it doesnt have a method []. However it supports a get method, for further read on this link. I have made few changes to your code and below is a working version.

if not already added, please add firebase_core: ^0.5.0 as dependency in pubspec.yaml

    import 'package:firebase_core/firebase_core.dart';
    import 'package:flutter/material.dart';
    import 'package:cloud_firestore/cloud_firestore.dart';
    
    class HomePage extends StatelessWidget {
      @override
      Widget build(BuildContext context) {
        return FutureBuilder(
          future: Firebase.initializeApp(),
          builder: (context, snapshot) {
            final FirebaseFirestore _fireStore = FirebaseFirestore.instance;
            return Scaffold(
                appBar: AppBar(
                  title: Text('Área do Cliente'),
                ),
                body: Container(
                    child: StreamBuilder(
                        stream: _fireStore
                            .collection("users")
                            .snapshots(),
                        builder: (context, snapshot) {
                          return ListView(
                            children: makeListWiget(snapshot),
                          );
                        })));
          },
        );
      }

  List<Widget> makeListWiget(AsyncSnapshot snapshot) {
    return snapshot.data.documents.map<Widget>((document) {
      return ListTile(
        title: Text(document.get('name')),
        subtitle: Text(document.get('lastname')),
      );
    }).toList();
  }
}
user_57163260
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