How to get text from a KivyMD text field? - kivy

Question

I am trying to get text from a text field, but I can't seem to get it right. I want to get the text from the MDTextField in the LoginScreen. This is my .kv file:
ScreenManager:
LoginScreen:
VaultScreen:
<LoginScreen>:
id: login
name: 'login'
MDTextField:
id: master_password
hint_text: "Master Password"
size_hint_x: None
width: 200
font_size: 18
pos_hint: {"center_x": 0.5, "center_y": 0.5}
password: True
MDRectangleFlatButton:
text: "Unlock"
font_size: 12
pos_hint: {"center_x": 0.5, "center_y": 0.4}
on_release: app.verify()
<VaultScreen>:
name: 'vault'
MDLabel:
text: 'Vault'
halign: 'center'
MDRectangleFlatButton:
text: 'Back'
pos_hint: {'center_x': 0.5, 'center_y': 0.1}
on_press: root.manager.current = 'login'
And this is my .py file:
from kivymd.app import MDApp
from kivy.lang.builder import Builder
from kivy.uix.screenmanager import ScreenManager, Screen
class ScMn(ScreenManager):
pass
class LoginScreen(Screen):
pass
class VaultScreen(Screen):
pass
class App(MDApp):
def build(self):
screen = Builder.load_file('passr.kv')
return screen
def verify(self):
# this is where I want to get the text
master = self.root.ids.login.master_password.text
pass
App().run()
When I try getting the contents of self.root.ids I get an empty dictionary.

Answer 1

Your code:
self.root.ids.login.master_password.text
is trying to access the ids of self.root, but self.root is the ScreenManager, and it has no ids. The ids defined in kv are stored in the ids dictionary of the widget that is the the root of the rule that contains the id definition. Since you define some ids in the <LoginScreen> rule, the ids will be in the LoginScreen object. So you must get a reference to the LoginScreen, and you can do that by using the get_screen() method, like this:
self.root.get_screen('login').ids.master_password.text