How to fix 'getter “documents” was called on null.' in flutter?

Question

The code Works with firebase and however, when I do that, an error saying:

The following NoSuchMethodError was thrown building StreamBuilder(dirty, state: _StreamBuilderBaseState<dynamic, AsyncSnapshot>#458db): The getter 'documents' was called on null. Receiver: null Tried calling: documents

 Widget _listBuilder() {
   if (cars != null) {
     return StreamBuilder (
       stream: cars,
       builder: (context, snapshot) {
         return ListView.builder(
           // ignore: deprecated_member_use
           itemCount: snapshot.data.documents.length,
           itemBuilder: (context, i) {
             return ListTile(
               // ignore: deprecated_member_use
               title: Text(snapshot.data.documents[i].data()['carName']),
               // ignore: deprecated_member_use
               subtitle: Text(snapshot.data.documents[i].data()['carColor']),
               // ignore: deprecated_member_use
               trailing: Text(snapshot.data.documents[i].data()['manYear']),
               onTap: () {
                 updateDialog(context, snapshot.data.documents[i].documentID);
               },
               onLongPress: () {
                 crudObj.deleteData(snapshot.data.documents[i].documentID);
               },
             );
           },
         );
       },
     );
   }
   else {
     return Text("Please Wait");
   }
 }

Does this answer your question? [What is a NoSuchMethod error and how do I fix it?](https://stackoverflow.com/questions/64049102/what-is-a-nosuchmethod-error-and-how-do-i-fix-it) — nvoigt, Nov 24 '20 at 13:12

score 0 · Answer 1 · answered Nov 24 '20 at 11:50

0

You should check if snapshot.hasData before other checks. Also you should be aware of snapshot.hasError and snapshot.connectionState. See StreamBuilder example in order to build async widget.

answered Nov 24 '20 at 11:50

Owczar

2,335
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score 0 · Answer 2 · answered Nov 24 '20 at 12:12

Try to check if your snapshot has data or not before directly using data

Here is complete code

 if (cars != null) {
     return StreamBuilder (
       stream: cars,
       builder: (context, snapshot) {
         if(snapshot.hasData){
           return ListView.builder(
           // ignore: deprecated_member_use
           itemCount: snapshot.data.documents.length,
           itemBuilder: (context, i) {
             return ListTile(
               // ignore: deprecated_member_use
               title: Text(snapshot.data.documents[i].data()['carName']),
               // ignore: deprecated_member_use
               subtitle: Text(snapshot.data.documents[i].data()['carColor']),
               // ignore: deprecated_member_use
               trailing: Text(snapshot.data.documents[i].data()['manYear']),
               onTap: () {
                 updateDialog(context, snapshot.data.documents[i].documentID);
               },
               onLongPress: () {
                 crudObj.deleteData(snapshot.data.documents[i].documentID);
               },
             );
           },
         );
         }
       },
     );
   }
   else {
     return Text("Please Wait");
   }

How to fix 'getter “documents” was called on null.' in flutter?

2 Answers2