Login System in Kivy

Question

I am new to Kivy, and I want to create a simple login system for desktop app.

Here's my python code:

class LoginPage(Screen):
    pass
class UserPage(Screen):
    pass
class ScreenManagement(ScreenManager):
    pass

kv_file = Builder.load_file('login.kv')
class LoginApp(App):
    def builder(self):
        return kv_file

LoginApp().run()

and kivy file

ScreenManagement:
    LoginPage:
    UserPage:
<LoginPage>:
    name: "login_page"
    BoxLayout:
        TextInput:
            id: login
        TextInput:
            id: passw
        Button:
            text: "go"
            on_release: app.root.current = "user"
<UserPage>:
    name: "user"
    Button:
        text: "back"
        on_release: app.root.current = "login_page"

I want it to change the screen only if text in form is what I need (e.g - TextInput(login) = 'username', TextInput(pass) = 'password').

I know I need to write a method for this, but I need help with this.

Solution

You must create a method that I get the texts and do the verification. This method should be called when the button is pressed. If the credentials are correct you must change the Screen.

*.py

from kivy.app import App
from kivy.uix.screenmanager import ScreenManager, Screen
from kivy.lang.builder import Builder

class LoginPage(Screen):
    def verify_credentials(self):
        if self.ids["login"].text == "username" and self.ids["passw"].text == "password":
            self.manager.current = "user"

class UserPage(Screen):
    pass

class ScreenManagement(ScreenManager):
    pass

kv_file = Builder.load_file('login.kv')

class LoginApp(App):
    def builder(self):
        return kv_file

if __name__ == '__main__':
    LoginApp().run()

*.kv

ScreenManagement:
    LoginPage:
    UserPage:

<LoginPage>:
    name: "login_page"
    BoxLayout:
        TextInput:
            id: login
        TextInput:
            id: passw
            password: True # hide password
        Button:
            text: "go"
            on_release: root.verify_credentials()

<UserPage>:
    name: "user"
    Button:
        text: "back"
        on_release: app.root.current = "login_page"

Comments

[Juggernaut]

screen_manager.switch_to(Screen())