Python Gio.Task binding missing

[ondrej (Ondřej Kolín)]

I can’t find GTask interface for Python in either Fedora 31 builds and in flatpak org.gnome.Platform builds. This makes building async based application really hard to do. Am I missing something here? Or it is just a bad state of python bindings? Should I create bug report for this issue?

I want to use Gio.Task for async calls with Python and Gtk Widgets.

Regards Ondrej

[ebassi (Emmanuele Bassi)]

You haven’t told us how you’re trying to use GTask.

Anyway, GTask is part of GIO, so you need something like this (WARNING: untested code):

class Foo (GObject.Object):
    def __init__(self):
          GObject.Object.__init__(self)

    def bar(self, question):
        '''
        @question: the question to ask

        Computes the answer synchronously.
        '''
        # long running computation
        return 42

    def bar_async(self, question, cancellable, callback):
        '''
        @question: the question to ask
        @cancellable: a Gio.Cancellable, or None
        @callback: (callable): a function to be called when the result is
          available; takes two arguments: callback(self, result)

        Runs bar() asynchronously.
        '''
        def bar_in_thread(task, self, data, cancellable):
            res = self.bar(data.get('question'))
            task.return_int(res)

        # Pass the arguments for bar as data to the task
        task_data = { 'question': question }

        task = Gio.Task.new(self, cancellable, callback)
        task.set_task_data(task_data)
        task.run_in_thread(bar_in_thread)

    def bar_finish(self, result):
        """
        To be called in the callback passed to bar_async(); result
        is the asynchronous result of the callback
        """
        return result.propagate_int()

[ondrej (Ondřej Kolín)]

Thanks! What a bad question. Maybe it will at least help some Googler. Thanks