how can i have an logout option in my flutter application? - firebase

Question

i have developed an admin app in that i have login page that directs to my dashboard ther i have option for log out but i'm not able to do it.
Here's my code:
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Row(
children: <Widget>[
Expanded(
child: FlatButton.icon(
onPressed: () {
setState(() => _selectedPage = Page.dashboard);
},
icon: Icon(
Icons.dashboard,
color: _selectedPage == Page.dashboard
? active
: notActive,
),
label: Text('Dashboard'))),
Expanded(
child: FlatButton.icon(
onPressed: () {
setState(() => _selectedPage = Page.manage);
},
icon: Icon(
Icons.sort,
color:
_selectedPage == Page.manage ? active : notActive,
),
label: Text('Manage'))),
],
),
elevation: 0.0,
backgroundColor: Colors.white,
),
body: _loadScreen());
}
Widget _loadScreen() {
switch (_selectedPage) {
case Page.dashboard:
return FutureBuilder(
future: getUsersCount(),
builder: (BuildContext context, AsyncSnapshot<String> text) {
print(text);
if(text== "-1"){
return CircularProgressIndicator();
} else {
return Column(
children: <Widget>[
ListTile(
subtitle: Text('Admin View', textAlign: TextAlign.center,
style: TextStyle(fontSize: 29.0,
color: Colors.indigo,
fontWeight: FontWeight.bold),),
),
Expanded(child: GridView(
gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(
crossAxisCount: 2,),
children: <Widget>[
Padding(padding: const EdgeInsets.all(18.0),
child: Card(child: ListTile(
title: FlatButton.icon(
onPressed: null,
icon: Icon(
Icons.people, color: Colors.black,),
label: Text("Users", style: TextStyle(
fontSize: 9, color: Colors.indigo),)),
subtitle: Text(text.data != null ? text.data : '',
textAlign: TextAlign.center,
style: TextStyle(color: active, fontSize: 50.0),
)),
),
),
],
),
),
],
);
}
});
break;
case Page.manage:
return ListView(
children: <Widget>[
ListTile(
leading: Icon(Icons.lock,color: Colors.black,),
title: Text("Logout",style: TextStyle(color: Colors.indigo),),
onTap: () {
Navigator.push(context, MaterialPageRoute(builder: (context)=> AdminLogin()));
// _brandAlert();
},
),
Divider(),
],
);
break;
default:
return Container();
}
}
void _categoryAlert() {
var alert = new AlertDialog(
content: Form(
key: _categoryFormKey,
child: TextFormField(
controller: categoryController,
validator: (value){
if(value.isEmpty){
return 'category cannot be empty';
}
return null;
},
decoration: InputDecoration(
hintText: "add Promocode",
),
),
),
actions: <Widget>[
FlatButton(onPressed: (){
if(categoryController.text != null){
_categoryService.createCategory(categoryController.text);
}
Fluttertoast.showToast(msg: 'Promocode changed');
Navigator.pop(context);
}, child: Text('ADD')),
FlatButton(onPressed: (){
Navigator.pop(context);
}, child: Text('CANCEL')),
],
);
showDialog(context: context, builder: (_) => alert);
}
}
i want the admin dashboard to be logged out and then switch to my login page again.

Answer 1

replace this line
Navigator.push(context, MaterialPageRoute(builder: (context)=> AdminLogin()));
with
final route = MaterialPageRoute(builder: (BuildContext context) => AdminLogin());
Navigator.of(this.context).pushAndRemoveUntil(route, (Route<dynamic> route) => false);

Answer 2

U need pushReplacementNamed rather then only push,
Navigator.pushReplacementNamed(context, '/Login');
or
navigator.pushReplacement(
MaterialPageRoute(builder: (BuildContext context) => Login()));
Use-case : pushReplacementNamed
When the user has logged in successfully, and are now on the DashboardScreen perhaps, then you don’t want the user to go back to LoginScreen in any case. So login route should be completely replaced by the dashboard route. Another example would be going to HomeScreen from SplashScreen. It should only display once and the user should not be able to go back to it from HomeScreen again. In such cases, since we are going to a completely new screen, we may want to use this method for its enter animation property. Read more on this