Error: Class 'QuerySnapshot' has no instance getter 'data' - flutter

Question

I'm trying to creat a UI screen with 3 tabs in it. RecentItem, ReviewItem and Profile. however there's some backend problem in recentitem widget. With the error shown: Class 'QuerySnapshot' has no instance getter 'data'.
Ps: The whole code is quite big hence I have shared a doc for the whole code: https://docs.google.com/document/d/1qs4ajPJ0DBjserBJ3iBZmPXPz1zTP7tIYSh8vceVQn8/edit?usp=sharing
RecentItems():
Widget RecentItems() {
return Padding(
padding: const EdgeInsets.all(10.0),
child: StreamBuilder(
stream: Firestore.instance
.collection("users")
.document(uid)
.collection("recent")
.snapshots(),
builder: (context, snapshot) {
print(snapshot.data);
List orders = List.from(Map.from(snapshot.data.data)['orders']);
Map order;
for (int i = 0; i < orders.length; i++) {
if (orders[i]['orderId'] == widget.map['orderId'] &&
orders[i]['homemaker'] == widget.map['homemaker']) {
order = orders[i];
break;
}
}
if (snapshot.data.isEmpty) {
return Center(
child:
Text("OOPS, Looks like no one is serving!"));
}
print(order);
if (snapshot.connectionState == ConnectionState.waiting) {
return Center(child: CircularProgressIndicator());
} else if (snapshot.hasData) {
print(snapshot.data.documents[0].data);
return Container(
height: 400,
child: ListView.builder(
itemCount: snapshot.data.documents.length,
itemBuilder: (BuildContext context, int index) {
return Container(
margin: EdgeInsets.all(10.0),
width: MediaQuery
.of(context)
.size
.width,
height: 85,
decoration: BoxDecoration(
color: Colors.white,
borderRadius: BorderRadius.circular(10.0),),
child: Padding(
padding: const EdgeInsets.all(10.0),
child: Column(
mainAxisAlignment: MainAxisAlignment.start,
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
Row(
children: <Widget>[
Expanded(child: Text(
"${snapshot.data.documents[index]
.data["dishname"]}", style: TextStyle(
fontSize: 15,
fontWeight: FontWeight.bold),)),
//Icon: how to access if food is veg or not
],
),
// SizedBox(height:5),
Row(
children: <Widget>[
Expanded(child: Text(
"${snapshot.data.documents[index]
.data["homemaker"]}",
style: TextStyle(fontSize: 10),)),
Text("${snapshot.data.documents[index]
.data["rating"]}",
style: TextStyle(fontSize: 15)),
Icon(
Icons.star, color: Colors.yellow.shade800,
size: 20,)
],
),
SizedBox(height: 5),
//How to access order date
Text(
"Ordered ${DateTime
.parse(order['order_placed_at']
.toDate()
.toString())
.day}/${DateTime
.parse(order['order_placed_at']
.toDate()
.toString())
.month}/${DateTime
.parse(order['order_placed_at']
.toDate()
.toString())
.year}}",
style: TextStyle(fontSize: 15.0,
fontWeight: FontWeight.bold),
),
],
),
),
);
}),
);
} //
}),
);
}
The Error Message is:
The getter 'data' was called on null.
Receiver: null
Tried calling: data
The relevant error-causing widget was:
StreamBuilder<QuerySnapshot> file:///C:/Flutter/Naniz_eats/lib/UserProfilePage.dart:434:14
════════════════════════════════════════════════════════════════════════════════════════════════════
I/flutter (28940): Instance of 'QuerySnapshot'
════════ (3) Exception caught by widgets library ═══════════════════════════════════════════════════
Class 'QuerySnapshot' has no instance getter 'data'.
Receiver: Instance of 'QuerySnapshot'
Tried calling: data
The relevant error-causing widget was:
StreamBuilder<QuerySnapshot> file:///C:/Flutter/Naniz_eats/lib/UserProfilePage.dart:434:14

Answer 1

Several things or all might be causing this:
the print from the first line of builder. If snapshot was indeed empty you would already be calling data without first checking if it is empty.
snapshot.data.data which I think is a typo in the second line of builder
The fact that you are doing operations on snapshot without first checking for snapshot.hasData, snapshot.data.documents.length != 0 to ensure that you are not doing operations on null snapshots.
You should also be able to check specifically which line is causing the error by pressing on the error messages, one of the error messages should contain a link to the specific line (not shown in your question, should be somewhere between the long stacks of error messages)

Answer 2

This code:
Firestore.instance
.collection("users")
.document(uid)
.collection("recent")
.snapshots()
returns a Stream of type QuerySnapshot, the problem is here:
List orders = List.from(Map.from(snapshot.data.data)['orders']);
the code snapshot.data will return an instance of QuerySnapshot and QuerySnapshot does not contain a instance variable called data. So, if you want to a list of documents then you have to do the following:
List<DocumentSnapshot> orders = snapshot.data.documents;
https://github.com/FirebaseExtended/flutterfire/blob/master/packages/cloud_firestore/cloud_firestore/lib/src/query_snapshot.dart#L17