Validate TextFormField with flutter hooks

I'm trying to move to flutter_hooks but I can't get some simple textformField validation to work.

I have 2 textfields and a button and I'd like to show an error on some conditions (or at least when the textfield is empty)

My code: -controllers:

final _emailFieldController =
        useTextEditingController.fromValue(TextEditingValue.empty);

    final _password =
        useTextEditingController.fromValue(TextEditingValue.empty);
    final _onSavePressed = useState(false);

-widgets:

TextFormField(
                  decoration: InputDecoration(hintText: "Your email"),
                  controller: _emailFieldController,
                ),
                TextFormField(
                  obscureText: true,
                  onSaved: (newValue) => print(newValue),
                  validator: (value) =>
                      _onSavePressed.value && _password.text.isEmpty
                          ? "Can't be empty"
                          : null,
                  decoration: InputDecoration(
                    hintText: "Password",
                  ),
                  controller: _password,
                ),
                RaisedButton(
                  child: Text("Create"),
                  onPressed: () {
                    _onSavePressed.value = true;
                  },
                )

Thank you for your help!

Use value that you get from validator. for example

validator: (value) => value.isEmpty ? "Can't be empty" : null

gives you access to the value of the password field.