Access Provider variable in child widget methods - flutter

Question

I'm trying to access branchSelected, a Provider declared towards the top of my code in the scaffold's child widgets. When I use branchSelected.branchDropdownValue in the original widget, it works. However, when I go into the child widget methods, specifically
ElevatedButton(
onPressed: () {
branchSelected.branchChange;
/*
refreshBranchData();
refreshProjectData();
*/
},
child: Icon(Icons.refresh))
, I received the error "Undefined name 'branchSelected'." Looking at other documentation, I thought that all child widgets should be able to access the Provider; however, that doesn't seem to be the case here. Any ideas? I've attached my code below:
#override
Widget build(BuildContext context) {
final branchSelected = Provider.of<branchListChanges>(context);
return Scaffold(
appBar: AppBar(
title: Text('Build Launcher'),
),
body: Padding(
padding: const EdgeInsets.all(8.0),
child: Column(
children: [
_buildTopRow(),
Consumer<branchListChanges>(builder: (context, data, child) {
return Text(
'Current Branch: ${branchSelected.branchDropdownValue}');
}),
_buildList(),
],
),
),
backgroundColor: Colors.grey[200],
);
}
Expanded _buildList() {
// Sets which branch to view for the list runs
return Expanded(
child: RunList(branches, "main"),
);
}
Row _buildTopRow() {
return Row(
children: [
Text("Project:"),
SizedBox(width: 6),
ProjectDropdown(packages),
SizedBox(width: 6),
Text("Branch:"),
SizedBox(width: 6),
BranchDropdown(branchNames),
SizedBox(width: 6),
Checkbox(
checkColor: Colors.white,
fillColor: MaterialStateProperty.all<Color>(Colors.blue),
value: onlyLatestPerDay,
onChanged: (bool? value) {
setState(() {
onlyLatestPerDay = value!;
});
},
),
SizedBox(width: 3),
Text("Only latest per-day"),
SizedBox(width: 6),
Checkbox(
checkColor: Colors.white,
fillColor: MaterialStateProperty.all<Color>(Colors.blue),
value: onlyInstalled,
onChanged: (bool? value) {
setState(() {
onlyInstalled = value!;
});
},
),
SizedBox(width: 3),
Text("Only installed"),
SizedBox(width: 6),
ElevatedButton(
onPressed: () {
branchSelected.branchChange;
/*
refreshBranchData();
refreshProjectData();
*/
},
child: Icon(Icons.refresh))
],
);
}
}
I created my Provider in main.dart attached below:
class HomePageState extends State<HomePage> {
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'cornerCan',
theme: ThemeData(
primarySwatch: Colors.blue,
),
// EFFECTS: runs mainPage function in main_page.dart
home: ChangeNotifierProvider<branchListChanges>(
create: (context) => branchListChanges(),
child: mainPage(),
),
);
}
}

Answer 1

The scope of your branchSelected variable is only inside the build function. You need to declare it outside the build function to access it.
You can also pass it as a parameter to the _buildTopRow() function
e.g. _buildTopRow(branchSelected)