open_file_dialog return object instead path string

[matteotanghe]

Describe the bug
If I want to have a path with the function open_file_dialog or select_folder_dialog it returns to me, the object.

To Reproduce
When I call open_file_dialog(), in my case, it return something like <toga_gtk.dialogs.OpenFileDialog object at 0x7f5e96c373c8>
Do I made something wrong ?
I make the function call like that :
self.filename = self.main_window.open_file_dialog("title", initial_directory=None, multiselect=True, file_types=['png', 'jpg']) print(self.filename)

Expected behavior
If I read the doc, normally the function open_file_dialog(title, initial_directory=None, file_types=None, multiselect=False, on_result=None)returns a string, in this case, the path. And this is what I need.

Environment:

• Operating System: Linux Ubuntu
• Python version: Python 3.6.9
• Software versions:
  • Briefcase: 0.3.6

It's little bit strange, maybe I made something wrong, but normally I easy the retrieve a path and I don't understand why it doesn't return me the same thing that the documentation.

[samschott]

@matteotanghe, you are not doing anything wrong, this is a shortcoming of the current documentation. The dialog methods all create the dialog and then immediately return a dialog object, such as <toga_gtk.dialogs.OpenFileDialog object ...> on Gtk. This means: they return before the user actual interacts with the dialog to select a file, click a button, etc., so that the method does not block the execution of the program.

You can await the returned object to get the actual result, in your case a string -- if you created the dialog inside a function defined with async def. For example:

async def select_file(self):
    path = await self.open_file_dialog()
    print("User selected:", path)

See https://docs.python.org/3/library/asyncio.html if you're not yet familiar with async programming in Python.

Alternatively, you can provide a function which will be called with the resulting path once the user has selected a file:

def print_path(window, path):
    print("User selected:", path)

def select_file(self):
    self.open_file_dialog(on_return= print_path)

@freakboy3742, I was expecting exactly such reports to come up after reading through #1464 :)

[matteotanghe]

Thank you, @samschott, I understand better now, how it's works and why :) .
Have a good day

[freakboy3742]

@samschott Yeah - it was somewhat inevitable; but also an unavoidable consequence of moving to async dialogs.

@matteotanghe Thanks for the report; I'll leave this ticket open as a marker that the docstrings need to be updated.