Update a widget value from another script?

[svandragt]

Hello, say I'm building an interface with a readonly MultilineTextInput. Now I want to add lines to the widget from another part of the application. Currently I do this:

app.py:

"""
test
"""
import toga

me = None


class MyApp(toga.App):
    def add_log(self, text):
        self.logbox.value += text
        self.logbox.refresh()

    def startup(self):
        box = toga.Box(style=Pack(direction=COLUMN))
        self.logbox = toga.MultilineTextInput(id='logbox', readonly=True)
        self.logbox.style.flex = 1
        box.add(self.logbox)

        self.main_window = toga.MainWindow(title=self.formal_name)
        self.main_window.content = box
        self.main_window.show()


def main():
    global me
    me = MyApp()
    return me

and in another part of the app:

from . import app

def example():
  app.me.add_log('Hello World')

Is that the best practice way? I was unable to find any example in the docs that updated a widget from outside the app class. As the widgets can all have an id should I be able to call a widget to update by their id for example? Thanks for your time.

[freakboy3742]

There will only ever be a single App instance in a running executable, and the app tracks that instance as App.app; so the following will do what you need:

import toga

def example():
    toga.App.app.add_log('Hello World')

However, generally speaking, I'd advise against relying on App.app. It works (and needs to exist for a variety of reason); but as a general matter of code style, if there's "another part of your app" that needs to know about the app, then it should be constructed and configured with a reference to the app (or, preferably, with a reference to a common data source that, when updated, is reflected in the app's GUI).