Change text of label does not update text of label KIVY - kivy

Question

I am trying to update a text of a label but it does not seem to update the text at all. I have a python file myfirebase.py and a kivy file signinscreen.kv.
The label id is "login_message" that I am trying to update. It is supposed to be updated in the python file with the following command: App.get_running_app().root.ids['signin_screen'] .ids['login_message'].text = 'invalid username or password'
There is no error; but it simply does not update the text of the label.
myfirebase.py:
"""
import requests
import json
from kivy.app import App
class MyFirebase():
def sign_in(self, username, password):
result_users =
requests.get("https://uniquedatabase-c4647-
default-rtdb.firebaseio.com/" + "users" + ".json")
data_users =
json.loads(result_users.content.decode())
incorrect_info = True
for users in data_users.values():
if username == users['username']:
passcode = users['password']
if password == passcode:
incorrect_info = False
App.get_running_app().my_user_id =
users
App.get_running_app().change_screen
('home_screen')
break
if incorrect_info:
App.get_running_app().root.ids['signin_screen']
.ids['login_message'].text = 'invalid username or
password'
"""
"""
<SigninScreen>:
FloatLayout:
GridLayout:
rows: 1
pos_hint: {"top": 1, "right": 1}
size_hint: 1, .2
Image:
source: 'images/Uniquelogo.jpg'
size: self.texture_size
TextInput:
id:login_username
hint_text: "username"
size_hint: .8,.1
pos_hint: {"top": .7, "right": .9}
TextInput:
id:login_password
hint_text: "password"
size_hint: .8,.1
pos_hint: {"top": .5, "right": .9}
Label:
id: login_message
text: ''
size_hint: .8,.1
pos_hint: {"top": .3, "right": .9}
color: 1,0,0,1
Button:
pos_hint: {"top": .2, "right": 0.75}
size_hint: 0.5, 0.25
text: 'Sign In'
color: 0,0,0,1
background_normal: ''
background_color: 1,0.95,0,1
on_release:
app.my_firebase.sign_in(login_username.text,
login_password.text)
"""
Main.py
"""
import sys
sys.path.append("/".join(x for x in __file__.split("/")
[:-1]))
from kivy.app import App
from kivy.lang import Builder
from kivy.uix.screenmanager import Screen
from kivy.uix.button import ButtonBehavior
from kivy.uix.image import Image
import requests
import json
from myfirebase import MyFirebase
from workoutbanner import WorkoutBanner
from kivy.properties import ListProperty, StringProperty,
ObjectProperty
from kivy.utils import platform
if platform == 'ios':
from pyobjus import autoclass
from kivy.clock import mainthread
class HomeScreen(Screen):
pass
class ImageButton(ButtonBehavior,Image):
pass
class SigninScreen(Screen):
pass
class MealofthedayScreen(Screen):
pass
class SettingsScreen(Screen):
pass
class SigninScreen(Screen):
pass
class ColorScreen(Screen):
pass
class MainApp(App):
native_image_picker = ObjectProperty(None)
image_path = StringProperty("")
my_user_id = "user1"
user_table = "users"
activity_table = "activities"
user_id = StringProperty('user1')
get_users = requests.get("https://uniquedatabase-c4647-default-
rtdb.firebaseio.com/" + user_table + ".json")
data_get_users = json.loads(get_users.content.decode())
image_source_profile =
StringProperty(str(data_get_users[my_user_id]['picture']))
color_writings = StringProperty(str(data_get_users[my_user_id]
['color']))
def build(self):
self.my_user_id = 'user1'
self.my_firebase = MyFirebase()
GUI = Builder.load_file("main.kv")
return GUI
def on_start(self):
#Query database data
if platform == 'ios':
self.native_image_picker =
autoclass("NativeImagePicker").alloc().init()
result_users = requests.get("https://uniquedatabase-c4647-
default-rtdb.firebaseio.com/" + self.user_table + ".json")
result_activities = requests.get("https://uniquedatabase-
c4647-default-rtdb.firebaseio.com/" + self.activity_table
+ ".json")
data_users = json.loads(result_users.content.decode())
data_activities =
json.loads(result_activities.content.decode())
streak_label =
self.root.ids['home_screen'].ids['streak_label']
streak_label.text = str(data_users[self.my_user_id]['streak'])
banner_grid = self.root.ids['home_screen'].ids['banner_grid']
for workouts in data_activities.values():
W =
WorkoutBanner(user=workouts['user'],
date=workouts['date'],
firstName=workouts['firstName']
,typeWorkout=workouts['typeOfWorkout'],
lenghtWorkout=workouts['lenghtOfWorkout']
,color_writings = self.color_writings)
banner_grid.add_widget(W)
def update(self):
print("Updating image...")
folder = "/".join(x for x in self.user_data_dir.split("/")
[:-1])
image_path = folder + "/" + "cached.png"
self.image_source_profile = image_path
my_profile_picture_data = '{"picture":"%s"}'%image_path
requests.patch("https://uniquedatabase-c4647-default-
rtdb.firebaseio.com/" + self.user_table + "/" +
self.my_user_id + ".json",
data=my_profile_picture_data)
def pick_image(self):
if platform == 'ios':
self.native_image_picker.displayImagePicker()
def changeColor(self,color):
if color == 'red':
color_code = 'ff0000'
my_color_data = '{"color":"%s"}'%color_code
requests.patch("https://uniquedatabase-c4647-default-
rtdb.firebaseio.com/" + self.user_table + "/" +
self.my_user_id + ".json",
data=my_color_data)
elif color == 'electric blue':
color_code = '0000ff'
my_color_data = '{"color":"%s"}'%color_code
requests.patch("https://uniquedatabase-c4647-default-rtdb.firebaseio.com/" + self.user_table + "/" + self.my_user_id + ".json",
data=my_color_data)
elif color == 'cyan':
color_code = '00eeee'
my_color_data = '{"color":"%s"}'%color_code
requests.patch("https://uniquedatabase-c4647-default-rtdb.firebaseio.com/" + self.user_table + "/" + self.my_user_id + ".json",
data=my_color_data)
elif color == 'green':
color_code = '008000'
my_color_data = '{"color":"%s"}'%color_code
requests.patch("https://uniquedatabase-c4647-default-rtdb.firebaseio.com/" + self.user_table + "/" + self.my_user_id + ".json",
data=my_color_data)
elif color == 'yellow':
color_code = 'ffff00'
my_color_data = '{"color":"%s"}'%color_code
requests.patch("https://uniquedatabase-c4647-default-rtdb.firebaseio.com/" + self.user_table + "/" + self.my_user_id + ".json",
data=my_color_data)
elif color == 'purple':
color_code = '9b30ff'
my_color_data = '{"color":"%s"}'%color_code
requests.patch("https://uniquedatabase-c4647-default-rtdb.firebaseio.com/" + self.user_table + "/" + self.my_user_id + ".json",
data=my_color_data)
#Fill HomeScreen feed
def change_screen(self,screen_name):
screen_manager = self.root.ids["screen_manager"]
screen_manager.current = screen_name
#mainthread
def on_correct_info(self, users):
self.my_user_id = users
self.change_screen('home_screen')
#mainthread
def on_incorrect_info(self):
self.root.ids['signin_screen'].ids['login_message'].text = 'invalid username or password'
MainApp().run()

Answer 1

I think there's an easier way to do this.
First of all, I noticed you're not using fstring, I highly recommend using it, in my code example, I've added it there for the requests.get function as an example.
As well, it seems you can have self.my_firebase = MyFirebase() under the Build function of the app and it should work with the code below
regarding the id "login_message" - You need to add the label also under SignInScreen, so all other widgets under SigninScreen can access it, finally, I passed login_message in the app.firebase_sigin function, and change its value from there.
<SigninScreen>
login_message: login_message
Please take a look, and let me know if you have any further questions:
myfirebase.py
from kivy.app import App
import requests
import json
class MyFirebase():
BASE_URL = 'https://uniquedatabase-c4647-default-rtdb.firebaseio.com'
def sign_in(self, username, password):
result_users = requests.get(f"{self.BASE_URL}/users.json")
data_users = json.loads(result_users.content.decode())
for users in data_users.values():
if username == users['username']:
passcode = users['password']
if password == passcode:
return True
else:
return False
kv
<SigninScreen>:
login_message: login_message
FloatLayout:
GridLayout:
rows: 1
pos_hint: {"top": 1, "right": 1}
size_hint: 1, .2
Label:
id: login_message
text: ''
size_hint: .8,.1
pos_hint: {"top": .3, "right": .9}
color: 1,0,0,1
TextInput:
id:login_username
hint_text: "username"
size_hint: .8,.1
pos_hint: {"top": .7, "right": .9}
TextInput:
id:login_password
hint_text: "password"
size_hint: .8,.1
pos_hint: {"top": .5, "right": .9}
Button:
pos_hint: {"top": .2, "right": 0.75}
size_hint: 0.5, 0.25
text: 'Sign In'
color: 0,0,0,1
on_release:
app.firebase_signin(login_username.text, login_password.text, login_message)
main.py
from kivy.app import App
from kivy.uix.screenmanager import Screen
from myfirebase import MyFirebase
from kivy.lang import Builder
...
class SigninScreen(Screen):
pass
....
class MainApp(App):
def firebase_signin(self, username, password, login_message):
succeeded = self.my_firebase.sign_in(username, password)
if succeeded:
# here you implement changing screens, etc..
do_something = "doing something.."
else:
login_message.text = "invalid username or password"
def build(self):
self.my_user_id = 'user1'
self.my_firebase = MyFirebase()
GUI = Builder.load_file("main.kv")
return GUI
MainApp().run()
Before pressing the signin button
After pressing the signin button