Fixes #314 - Convert func to string before saving task in databse so …

…that resubmitting failed task works (#554)

django_q/cluster.py

@@ -1,6 +1,7 @@
 # Standard
 import ast
-import importlib
+import inspect
+import pydoc
 import signal
 import socket
 import traceback
@@ -416,31 +417,22 @@ def worker(
         f = task["func"]
         # if it's not an instance try to get it from the string
         if not callable(task["func"]):
-            try:
-                module, func = f.rsplit(".", 1)
-                m = importlib.import_module(module)
-                f = getattr(m, func)
-            except (ValueError, ImportError, AttributeError) as e:
-                result = (e, False)
-                if error_reporter:
-                    error_reporter.report()
-        # We're still going
-        if not result:
-            close_old_django_connections()
-            timer_value = task.pop("timeout", timeout)
-            # signal execution
-            pre_execute.send(sender="django_q", func=f, task=task)
-            # execute the payload
-            timer.value = timer_value  # Busy
-            try:
-                res = f(*task["args"], **task["kwargs"])
-                result = (res, True)
-            except Exception as e:
-                result = (f"{e} : {traceback.format_exc()}", False)
-                if error_reporter:
-                    error_reporter.report()
-                if task.get("sync", False):
-                    raise
+            f = pydoc.locate(f)
+        close_old_django_connections()
+        timer_value = task.pop("timeout", timeout)
+        # signal execution
+        pre_execute.send(sender="django_q", func=f, task=task)
+        # execute the payload
+        timer.value = timer_value  # Busy
+        try:
+            res = f(*task["args"], **task["kwargs"])
+            result = (res, True)
+        except Exception as e:
+            result = (f"{e} : {traceback.format_exc()}", False)
+            if error_reporter:
+                error_reporter.report()
+            if task.get("sync", False):
+                raise
         with timer.get_lock():
             # Process result
             task["result"] = result[0]
@@ -495,10 +487,19 @@ def save_task(task, broker: Broker):
                 broker.acknowledge(task['ack_id'])
 
         else:
+            func = task["func"]
+            # convert func to string
+            if inspect.isfunction(func):
+                func = f"{func.__module__}.{func.__name__}"
+            elif inspect.ismethod(func):
+                func = (
+                    f'{func.__self__.__module__}.'
+                    f'{func.__self__.__name__}.{func.__name__}'
+                )
             Task.objects.create(
                 id=task["id"],
                 name=task["name"],
-                func=task["func"],
+                func=func,
                 hook=task.get("hook"),
                 args=task["args"],
                 kwargs=task["kwargs"],