added celery documentation, switched to optional_parameter_call, minor fixes

README.md

@@ -80,6 +80,22 @@ the test module will be at:
 
     http://127.0.0.1:8000/static/index.html
 
+Running periodic tasks 
+-------------------------------------
+Periodic tasks (which are scheduled with core.decorators.cron) 
+rely on Celery for execution. It is the reponsability of the
+client django project to ensure Celery is configured and running.
+To configure, add the following to settings.py of your django
+project: 
+    from edinsights.celerysettings import * 
+
+To start celery, run from your django project 
+    python manage.py celery worker -B
+
+Only tasks located in files named "tasks.py" located in the main 
+directory of your django project or installed django app will
+be scheduled.
+
 Building on top of the framework
 --------------------------------
 

src/edinsights/core/decorators.py

@@ -21,6 +21,8 @@ from django.core.cache import cache
 from django.conf import settings
 
 from celery.task import PeriodicTask, periodic_task
+from util import optional_parameter_call
+from util import default_optional_kwargs
 
 import registry
 from registry import event_handlers, request_handlers
@@ -124,7 +126,7 @@ def memoize_query(cache_time = 60*4, timeout = 60*15, ignores = ["<class 'pymong
             # process of computing it
             cached = cache.get(key)
             if cached:
-                print "Cache hit", f.__name__, key
+                # print "Cache hit", f.__name__, key
                 # If we're already computing it, wait to finish
                 # computation
                 while cached == 'Processing':
@@ -136,7 +138,7 @@ def memoize_query(cache_time = 60*4, timeout = 60*15, ignores = ["<class 'pymong
                 results = cached
 
             if not cached:
-                print "Cache miss",f.__name__, key
+                # print "Cache miss",f.__name__, key
                 # HACK: There's a slight race condition here, where we
                 # might recompute twice.
                 cache.set(key, 'Processing', timeout)
@@ -162,14 +164,11 @@ def cron(run_every, params=None):
     python manage.py celery worker -B --loglevel=INFO
     Celery beat will automatically add tasks from files named 'tasks.py'    
     '''
-    def factory(f):
-        @periodic_task(run_every=run_every, name=f.__name__)
+    def factory(func):
+        @periodic_task(run_every=run_every, name=func.__name__)
         def run():
-            from edinsights import core
-            mongodb = core.util.get_mongo(f)
-            fs = core.util.get_filesystem(f)
-            f(fs, mongodb, params)
-        return decorator(run,f)
+            optional_parameter_call(func, default_optional_kwargs, params)
+        return decorator(run,func)
     return factory
 
 def event_property(name=None, description=None):

src/edinsights/core/tests.py

@@ -14,7 +14,7 @@ from celery.task import periodic_task
 
 
 @cron(run_every=timedelta(seconds=1))
-def test_cron_task(*args):
+def test_cron_task():
     """ Simple task that gets executed by the scheduler (celery beat).
         The test case test_cron verifies that the execution
         has taken place.
@@ -28,7 +28,7 @@ def test_cron_task(*args):
 
 @cron(run_every=timedelta(seconds=1))  # cron decorators should go on top
 @memoize_query(60)
-def test_cron_memoize_task(*args):
+def test_cron_memoize_task():
     """ Simple task that gets executed by the scheduler (celery beat).
         The test case test_cron_and_memoize verifies that the execution
         has taken place.

src/edinsights/settings.py

@@ -194,9 +194,12 @@ LOGGING = {
     }
 }
 
-##uncomment to provide full location of code that uses naive datetime
-#import warnings
-#warnings.filterwarnings(
+# # By default timezone-related warnings do not display the location in code
+# # where they occurred. The code below will turn these warnings into
+# # exceptions with stack trace so that one can identify the offending code.
+# # Uncomment to turn timezone warnings into exceptions
+# import warnings
+# warnings.filterwarnings(
 #        'error', r"DateTimeField received a naive datetime",
 #        RuntimeWarning, r'django\.db\.models\.fields')