How to save the value of textformfield?

I have multiple TextFormFields that contains data pulled from Realtime Database and it gets displayed in an Edit Information page.

    final nameController = TextEditingController();
    final descriptionController = TextEditingController();

    setState(() {
      nameController.text = widget.name;
      descriptionController.text = widget.description;
    });

TextFormField(
   controller: nameController,
   autofocus: false,
   decoration: InputDecoration(
   labelText: 'Name',
   border: OutlineInputBorder(),),
),

Above codes will show name and description already in Edit Information page. However, when I type a new value for name and click on a different TextFormField, the name TextFormField goes back to its original value because of the controller. How can I save the state of the new TextFormField, if there is any, and update with the new value? Should I use onSaved or onChanged?

Information will be updated after clicking on this button:

ElevatedButton(
   onPressed: () {
   updateData(nameController.text,
   descriptionController.text, widget.passkey);
   Navigator.of(context).pop();},
   child: Text('Update')),

Update function:

  void updateData(String name, String description, var id) {
    Map<String, String> newvalue = {'name': name, 'description': description};
    databaseref.child(id).update(newvalue);
  }

>Solution :

This is due to setstate. Just remove Setstate from

setState(() {
      nameController.text = widget.name;
      descriptionController.text = widget.description;
    });

And Define your controller like

final controller = TextEditingController(text: "Your initial value");