pickling a gridlayout using python and kivy-CodePudding

i have been trying to save the state of my application using python pickle module without success. my application works fine on mobile but whenever i close it, it loses all data. i want this application to be like a table notepad so that i can resume from where i left after closing the app. here is a part of my code to explain the problem. example.py

import pickle


class MyGrid(BoxLayout):
    pass


if os.path.isfile("notepad"):
    load = pickle.load(open("notepad", "rb"))
    print(load)
    textinput = StringProperty(load)
else:
    textinput = StringProperty()


class Goat(App):
    def build(self):
        return MyGrid()

    def save(self):
        rectangle1 = [self.root.ids.a2.text, self.root.ids.a2.text]
        pickle.dump(rectangle1, open("notepad", "wb"))


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

here is my .kv file

<MyGrid>:
    orientation: 'vertical'
    ScrollView:
        bar_width: 10
        GridLayout:
            id:gridlayout
            cols :3
            row_default_height: 90
            height: self.minimum_height
            size: 600, 500
            padding: 5
            pos: 0, -200
            size_hint_y: None
##############################################box1
            Label:
                text : "A"
                background_color: (1, 5, 0, 1)
                font_size: 30
            TextInput:
                id : a1
                multiline : False
                font_size: 30
            TextInput:
                id : a2
                multiline : False
                font_size: 30
            Button:
                text: 'SUBMIT'
                id : submit1
                background_color: (1, 0, 0, 1)
                on_release: app.save()
                font_size: 39

when i type on the input field and press submit, a notepad.dat file is formed on the directory and the contents typed on the input field are saved.( i know this by print(load) on my .py file) my problem is bringing the contents of the dart file on the gui and making them stay there. i dont know how to do that. please help!

CodePudding user response：

You need to load the pickled data after the App starts so that you can assign the pickled data to the widgets. Like this:

class Goat(App):
    def on_start(self):
        if os.path.isfile("notepad"):
            load = pickle.load(open("notepad", "rb"))
            self.root.ids.a1.text = load[0]
            self.root.ids.a2.text = load[1]