CODEWITHSUNDEEP
androidfirebasefluttergoogle-cloud-firestore
Xor96
Xor96

Reputation: 432

How to retrieve the single document data and show it in app?

Here, I'm trying to print the username of the user and it produces the following error. The Error is as follows...

I created a function userData() and the code is

userData() async
  {
    var userData = await _db.collection('users').document(_uuid).get();
    return userData;
  }

Where I'll just get the data of the specific user using uid and returning it.

The code I used to print the data is as follow

return FutureBuilder(
    future: authService.userData(),
    builder: (_,snapshots){
      if(snapshots.connectionState == ConnectionState.waiting)
      {
        
        return Center(child: Text('Loading...'),);
      }
      else{
        print("Snapshots: "+snapshots.toString());
        return ListView.builder(itemCount: 1, itemBuilder: (_,index){
          return ListTile(
            title: Text(snapshots.data["username"].toString()),
          );
        });
      }
    }
  );

The structure of firestore is

Collection('user') -> document(uid) -> 1.username 2.email ....

What is the reason for this error and how to resolve it?

Upvotes: 0

Views: 348

Answers (2)

Doug Stevenson
Doug Stevenson

Reputation: 317760

The error message is telling you that snapshots.data is null, so you can't index into it with the [] operator.

Before using a DocumentSnapshot, you should check to see if it exists before accessing its field data. The snapshot's data property will be null if the document doesn't exist.

Upvotes: 2

Adarsh Balu
Adarsh Balu

Reputation: 352

For Firestore I would recommend using Stream Builder rather than future Builder.

return StreamBuilder(
    stream: Firestore.instance
                .collection('user')
                .document(uid)
                .snapshots(),
    builder: (_,snapshot){
      if(!snapshot.hasData)
      {
        
        return Center(child: Text('Loading...'),);
      }
      else{
        
        return ListView.builder(itemCount: 1, itemBuilder: (_,index){
          return ListTile(
            title: Text(snapshots.data["username"].toString()),
          );
        });
      }
    }
  );

Upvotes: 0

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