Call Django Class based view function with Django-Q's async_task

[ghost]

I can't call async_task on a Django class based view function. Considering following case, where I have a DRF view:

class Greeter(generics.GenericAPIView)

    def greet(self, name):
        print("Hello: ")
        sleep(5)
        print(name)

    def post(self, request, *args, **kwargs):
        # enqueue the task
        async_task(self.greet, "world")

        return Response(
            {"message": "you should see this right away"}, status=status.HTTP_200_OK
        )

When trying to call async_task on a Django class based view function, following errors occur:

• async_task(self.greet) returns an cannot pickle '_io.BufferedReader' object error
• async_task("self.greet") returns an No module named 'self' error

I have no issues when putting the greet function outside de class.

edit: correcting function names

[Koed00]

As a quick fix you could try to async the import path i.e. "Greeter.greet"

…

On Mon, 3 Aug 2020, 09:54 Alexis Richter, ***@***.***> wrote: I can't call async_task on a Django class based view function. Considering following case, where I have a DRF view: class Greeting(generics.GenericAPIView) def greet(self, name): print("Hello: ") sleep(5) print(name) def post(self, request, *args, **kwargs): # enqueue the task async_task(self.greet, "world") return Response( {"message": "you should see this right away"}, status=status.HTTP_200_OK ) When trying to call async_task on a Django class based view function, following errors occur: - async_task(self.greeting) returns an cannot pickle '_io.BufferedReader' object error - async_task("self.greet") returns an No module named 'self' error I have no issues when putting the greet function outside de class. — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#463>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AA6AQNOKJGHJJ5SODZTIITTR6ZUMJANCNFSM4PTCGLVA> .

[ghost]

As a quick fix you could try to async the import path i.e. "Greeter.greet"

I tried that as well, but then I have a No module named Greeter error.

[Koed00]

That probably means you are not giving it the full import parth ie: "myapp.Greeter.greet"

[mosi-kha]

hi
how in case that we need to create an instance of an object then pass that function from the instance, set that function to async_task?
ex: async_task(Test().print_test) but raise some pickle error

[Koed00]

Just create a separate task for this: ie def print_test(test: Test): return test.print_test() and then async this function with the Test() instance async_task(my_module.tasks.print_test, Test()) Only the arguments can be instances and will be serialized.

…

On Wed, Aug 12, 2020 at 10:25 AM mostafa khaki ***@***.***> wrote: hi how in case that we need to create an instance of an object then pass that function from the instance, set that function to async_task? ex: async_task(Test().print_test) but error some pickle error — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#463 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AA6AQNPHESQ2AS5UZ74X7OTSAJGWHANCNFSM4PTCGLVA> .

[rafael-h-ferreira]

I too have a class with many static methods and I wish to call the class functions. Instead of creating one separate task for each class function, I created one task that will run the class functions:

from my_proj import ProjClass
def run_task(class_static_method: str, *args, **kwargs):
    func = getattr(ProjClass, class_static_method)
    return func(*args, **kwargs)

Then you may call it like:

async_task("my_proj.run_task", "class_static_function", arg1)

Of course, if you need a class instance you need to instantiate it first in the run_task. If you also need to pass class args, you probably need a dict arg for the class args and other for the function args.