super' object has no attribute '__getattr__' error in kivy?

Question

Empty Field Empty Field Empty Field

Answer 1

Your code self.root.ids.input.text is trying to reference ids in the app root. There are two problems with that. First, the root is the WindowManager, which has no ids in your code. Second, there is no input id defined in your kv. The fix is to define an input id somewhere in your kv, and then use something like

self.root.get_screen('some_screen_name').ids.input.text

where some_screen_name is the name of the Screen that contains the input id.

Answer 2

your screen manager should look like this

WindowManager:
    FirstPageScreen:
        id: first_page_screen
        name: first_page_screen
    LoginPageScreen:
        id: login_page_screen
        name: login_page_screen
    NewAccountScreen:
        id: new_account_screen
        name: new_account_screen

your screens in the screen manager need to have ids and names so as to make them easier to reference from the screen manager

move the returnusername and returnpassword functions to the calling class, which will make them easier to access.

the button on the LoginPageScreen which made the call would look like this

MDRectangleFlatButton:
    halign: "center"
    valign: "center"
    text: "Submit"
    theme_text_color: "Custom"
    text_color: 1, 1, 1, 1
    md_bg_color: 0, 0, 1, 1
    line_color: 0, 0, 1, 1
    pos_hint: {'center_x': 0.5, 'center_y': 0.45}
    size_hint: 0.25, 0.05
    on_release: 
        root.returnusername()
        root.returnpassword()

and the functions in the LoginScreenPage class would be as below

class LoginPageScreen(MDScreen):
    def returnusername(self):
        text = self.ids.usernameinput.text
        print(text)
    def returnpassword(self):
        text = self.ids.passwordinput.text
        print(text)

in your kv file, <FirstPageScreen>:, <LoginPageScreen>:, <NewAccountScreen>: should no longer have the name attribute. that has been added in the screen manager. so calling the the screens with app.root.current will point to the new screen names added to screen manager.

Sometime how you structure your code affect how you understand the code and how to debug errors.