Adds wait option to result() and fetch()

README.rst

@@ -127,7 +127,10 @@ Use `async` from your code to quickly offload tasks:
     task_result = result(task_id)
 
     # result returns None if the task has not been executed yet
-    # so in most cases you will want to use a hook:
+    # you can wait for it
+    task_result = result(task_id, 200)
+
+    # but in most cases you will want to use a hook:
 
     async('math.modf', 2.5, hook='hooks.print_result')
 

django_q/tasks.py

@@ -5,6 +5,7 @@ from multiprocessing import Queue, Value
 from django.utils import timezone
 
 # local
+import time
 import signing
 import cluster
 from django_q.conf import Conf, logger
@@ -82,16 +83,25 @@ def schedule(func, *args, **kwargs):
                                    )
 
 
-def result(task_id):
+def result(task_id, wait=0):
     """
     Return the result of the named task.
 
     :type task_id: str or uuid
     :param task_id: the task name or uuid
+    :type wait: int
+    :param wait: number of milliseconds to wait for a result
     :return: the result object of this task
     :rtype: object
     """
-    return Task.get_result(task_id)
+    start = time.time()
+    while True:
+        r = Task.get_result(task_id)
+        if r:
+            return r
+        if (time.time() - start) * 1000 >= wait:
+            break
+        time.sleep(0.01)
 
 
 def result_group(group_id, failures=False):
@@ -105,16 +115,25 @@ def result_group(group_id, failures=False):
     return Task.get_result_group(group_id, failures)
 
 
-def fetch(task_id):
+def fetch(task_id, wait=0):
     """
     Return the processed task.
 
     :param task_id: the task name or uuid
     :type task_id: str or uuid
+    :param wait: the number of milliseconds to wait for a result
+    :type wait: int
     :return: the full task object
     :rtype: Task
     """
-    return Task.get_task(task_id)
+    start = time.time()
+    while True:
+        t = Task.get_task(task_id)
+        if t:
+            return t
+        if (time.time() - start) * 1000 >= wait:
+            break
+        time.sleep(0.01)
 
 
 def fetch_group(group_id, failures=True):

django_q/tests/test_cluster.py

@@ -230,6 +230,8 @@ def test_async(broker, admin_user):
     assert result_j.group_delete(tasks=True) is None
     # task k should not have been saved
     assert fetch(k) is None
+    assert fetch(k, 100) is None
+    assert result(k, 100) is None
     broker.delete_queue()
 
 

docs/tasks.rst

@@ -25,7 +25,10 @@ Use :func:`async` from your code to quickly offload tasks to the :class:`Cluster
     task_result = result(task_id)
 
     # result returns None if the task has not been executed yet
-    # so in most cases you will want to use a hook:
+    # you can wait for it
+    task_result = result(task_id, 200)
+
+    # but in most cases you will want to use a hook:
 
     async('math.modf', 2.5, hook='hooks.print_result')
 
@@ -208,19 +211,21 @@ Reference
    :returns: The uuid of the task
    :rtype: str
 
-.. py:function:: result(task_id)
+.. py:function:: result(task_id, wait=0)
 
     Gets the result of a previously executed task
 
     :param str task_id: the uuid or name of the task
+    :param int wait: optional milliseconds to wait for a result
     :returns: The result of the executed task
 
-.. py:function:: fetch(task_id)
+.. py:function:: fetch(task_id, wait=0)
 
     Returns a previously executed task
 
     :param str name: the uuid or name of the task
-    :returns: The task if any
+    :param in wait: optional milliseconds to wait for a result
+    :returns: A task object
     :rtype: Task
 
     .. versionchanged:: 0.2.0