def choose_next_task():
""" Calculate the next task to work on.
Starting at the top of the tree, we choose the top-level task to work
on, based on the default strategy stored in our preferences. If the
selected task has children, we then repeat the process for the child
task, using the selected task's strategy, continuing until we reach a
task with no children, which is the task to work on next.
Upon completion, we return the Task object to work on next, or None if
there are no task objects that we can work on.
"""
parent = None
strategy = preferences.get_int("TOP_LEVEL_STRATEGY",
Task.STRATEGY_PROPORTIONAL)
while True:
task = _calc_next_task_for_parent(parent, strategy)
if task == None:
return None
if task.children.filter(status=Task.STATUS_ACTIVE).exists():
# This task has at least one active child -> choose the task from
# among this task's children.
parent = task
strategy = task.strategy
continue
else:
# We've reached a leaf node task -> this is the one to work on.
return task
def prefs(request):
""" Respond to the "/prefs" URL.
This is the main view for the "prefs" mode.
"""
if request.method == "GET":
# We're displaying the form for the first time. Set up our defaults.
err_msg = None
strategy = preferences.get_int("TOP_LEVEL_STRATEGY")
elif request.method == "POST":
# Get the entered form values.
if request.POST.get("cancel") != None:
# The user cancelled -> return to the main page.
return HttpResponseRedirect("/")
err_msg = None # initially.
strategy = request.POST.get("strategy")
if strategy == None:
err_msg = "You must select a strategy."
if err_msg == None:
preferences.set_int("TOP_LEVEL_STRATEGY", strategy)
return HttpResponseRedirect("/")
# If we get here, display the preferences form.
return render(request, "prefs.html",
{'strategy_choices' : Task.STRATEGY_CHOICES,
'err_msg' : err_msg,
'strategy' : strategy})
