kivy How to get text in TextInput?

Question

Login System; i have a this error.How to get text in txt1 and how to change via button ?

File "/home/hypermesh/Desktop/main.py", line 11, in messageShow if self.txt1.text == "stock": AttributeError: 'Button' object has no attribute 'txt1'

#-*- coding: utf-8 -*-
from kivy.app import App
from kivy.uix.label import Label
from kivy.uix.button import Button
from kivy.uix.popup import Popup
from kivy.uix.textinput import TextInput
from kivy.uix.gridlayout import GridLayout
from kivy.uix.widget import Widget

def messageShow(self):
    if self.txt1.text == "stock":
        pop=Popup(text="yes")
    else:
        pop=Popup(text="error")

class SimpleKivy(App):

    def build(self):
        grid=GridLayout(rows=3, cols=2)
        lbl1=Label(text="ID :",italic=True, bold=True)
        lbl2=Label(text="Password :",italic=True, bold=True)
        txt1=TextInput(multiline=False, font_size=50)
        txt2=TextInput(multiline=False, password=True)
        btn1=Button(text="Exit",italic=True)
        btn2=Button(text="OK",italic=True)

        btn2.bind(on_press=messageShow)

        grid.add_widget(lbl1)
        grid.add_widget(txt1)
        grid.add_widget(lbl2)
        grid.add_widget(txt2)
        grid.add_widget(btn1)
        grid.add_widget(btn2)
        return grid

if __name__ == "__main__":
    SimpleKivy().run() 

Answer 1

you did it right ... but you must save a reference to anthing you want to access later (usually attaching it to self)

def __init__(...):
    ...
    self.txt1=TextInput(multiline=False, font_size=50)
    ...

then your other function should work fine (except the method should be part of the class..)

class SimpleKivy(App):
    def messageShow(self,evt):
        if self.txt1.text == "stock":
            pop=Popup(text="yes")
        else:
            pop=Popup(text="error")

    def build(self):
        grid=GridLayout(rows=3, cols=2)
        lbl1=Label(text="ID :",italic=True, bold=True)

another alternative is to use lambdas to call it

def messageShow(message):
     print "GOT MESSAGE:",message

class SimpleKivy(App):
     def __init__(self,...):
         txt1 = TextInput(...)
         ...
         btn.bind(on_press=lambda *a:messageShow(txt1.text))

in this case txt1 is in the variable scope and able to pass its string to messageShow