CODEWITHSUNDEEP
flutterdart
Василий Гринько
Василий Гринько

Reputation: 43

delay before rendering streamBuilder

I have streamBuilder, when I go to the page with it for a split second there is an error about the zero return of the function, i.e. the data does not have time to load and the function returns null

if (customers != null) {
  return StreamBuilder(
    stream: customers,
    //initialData: ,
    builder: (context, AsyncSnapshot snapshot) {
    if (snapshot.hasData) {
      if (snapshot.data != null) {
          return ListView.builder(
            itemCount: snapshot.data.documents.length,
            padding: EdgeInsets.all(5.0),
            itemBuilder: (context, i) {
              return new ListTile(
                title:
                Column(mainAxisAlignment: MainAxisAlignment.start,
                    children: <Widget>[
                    Text(snapshot.data.documents[i].data['pickedDay'],),
                    Text(snapshot.data.documents[i].data['pickedTime']),
                    Text(snapshot.data.documents[i].data['service']),
                    Text(snapshot.data.documents[i].data['phoneNumber']),
                    Divider(height: 10, color: primaryColor2),
                  ],),
                },
              );
            },
          );
        }
      }
   // }
    },
  );
} else {
return new CircularProgressIndicator();
}

}>

How can i fix this?

Upvotes: 2

Views: 972

Answers (1)

jbarat
jbarat

Reputation: 2460

Your builder is not returning data when snapshot.hasData is false. That's why you see that error.

You should return something. It can be just an empty container or a loading spinner. Something like this:

if (snapshot.hasData || snapshot.data != null) {
  //your current code
}else{
  return Container()
}

Upvotes: 4

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