I'm trying to implement a check that if user displayName is null in firebase. It should navigate to a form where he has to enter his name. Currently displayName in firebase is null by default. But i'm getting an error.

A non-null String must be provided to a Text widget.

'package:flutter/src/widgets/text.dart':

Failed assertion: line 360 pos 10: 'data != null'

```
Row(
  children: [
    Container(
      margin: EdgeInsets.only(bottom: 50, left: 30),
      child: Column(
        mainAxisAlignment: MainAxisAlignment.center,
        //crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Text("Welcome !"),
          // ignore: unrelated_type_equality_checks
          Text(snapshot.data.documents
                      .elementAt(index)['displayName']) !=
                  null
              ? Text(snapshot.data.documents
                  .elementAt(index)['displayName'])
              : Navigator.pushNamed(context, '/UserDetail'),
        ],
      ),
    ),
  ],
),

```