(I'm new to python and django so please bear with me for a second. I apologise if this has been answered elsewhere and couldn't find it)
Let's say I have a Link model and through the django-voting application users can vote on link instances. How can I order those link instances according to their score, eg. display those with the higher score first.
I assume I could use the get_top manager of django-voting, but that would only give me the top scoring link instances and wouldn't take into consideration other parameters I would like to add (for example, those links that belong to a specific user or paging or whatever).
My guess would be to write a custom manager for my Link model where by I can filter a queryset according to each item's score. If I understand correctly that will require me to loop through each item, check its score, and then place it a list (or dictionary) which will th开发者_Go百科en be sorted according to the score of each item. That wouldn't return a queryset but a dictionary with each item.
Am I missing something here?
edit:
Here's a stripped-down version of the Link model:
class Link(models.Model):
user = models.ForeignKey('auth.User')
category = models.ForeignKey(Category)
date = models.DateTimeField( auto_now_add=True, null=True, blank=True )
is_deleted = models.BooleanField(default=False, blank=True)
links = ValidLinkManager()
objects = models.Manager()
and when a user votes I have this in my view:
Vote.objects.record_vote(link, user, vote)
where link is the Link instance, user is an instance of auth.User and vote is either 1, 0, or -1. The ValidLinkManager just filters out those links that have is_deleted set to True.
The get_top
method in VoteManager isn't that complicated. Look at its code (in managers.py:122). You can easily create a version of it that accepts a filter as another parameter and applies it to the "objects" queryset after it creates it, in line 158 - this way you can add other filters like the ones you're missing.
Maybe you can also offer that as a patch back to the jonathan, and he'll put it in django-voting :)
I chose to use a generic relation in my model:
votes = generic.GenericRelation(Vote)
and then to aggregate it:
my_model.objects.annotate(num_votes=Count('votes'))
In this case I am just counting the number of votes received by the objects, but you can switch Count
with Avg
to get an average.
Since this does not work with Django by default, I installed django-generic-aggregation
.
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