Here's the gist of my solution. I use images with jQuery/AJAX to handle clicks. Strongly influenced by this site. There's some stuff that could use some work (error handling in the client, for example -- and much of it could probably be refactored) but hopefully the code is useful to you.
The HTML:
<div class="vote-buttons">
{% ifequal thisUserUpVote 0 %}
<img class="vote-up" src = "images/vote-up-off.png" title="Vote this thread UP. (click again to undo)" />
{% else %}
<img class="vote-up selected" src = "images/vote-up-on.png" title="Vote this thread UP. (click again to undo)" />
{% endifequal %}
{% ifequal thisUserDownVote 0 %}
<img class="vote-down" src = "images/vote-down-off.png" title="Vote this thread DOWN if it is innapropriate or incorrect. (click again to undo)" />
{% else %}
<img class="vote-down selected" src = "images/vote-down-on.png" title="Vote this thread DOWN if it is innapropriate or incorrect. (click again to undo)" />
{% endifequal %}
</div> <!-- .votebuttons -->
The jQuery:
$(document).ready(function() {
$('div.vote-buttons img.vote-up').click(function() {
var id = {{ thread.id }};
var vote_type = 'up';
if ($(this).hasClass('selected')) {
var vote_action = 'recall-vote'
$.post('/ajax/thread/vote', {id:id, type:vote_type, action:vote_action}, function(response) {
if (isInt(response)) {
$('img.vote-up').removeAttr('src')
.attr('src', 'images/vote-up-off.png')
.removeClass('selected');
$('div.vote-tally span.num').html(response);
}
});
} else {
var vote_action = 'vote'
$.post('/ajax/thread/vote', {id:id, type:vote_type, action:vote_action}, function(response) {
if (isInt(response)) {
$('img.vote-up').removeAttr('src')
.attr('src', 'images/vote-up-on.png')
.addClass('selected');
$('div.vote-tally span.num').html(response);
}
});
}
});
The Django view that handles the AJAX request:
def vote(request):
thread_id = int(request.POST.get('id'))
vote_type = request.POST.get('type')
vote_action = request.POST.get('action')
thread = get_object_or_404(Thread, pk=thread_id)
thisUserUpVote = thread.userUpVotes.filter(id = request.user.id).count()
thisUserDownVote = thread.userDownVotes.filter(id = request.user.id).count()
if (vote_action == 'vote'):
if (thisUserUpVote == 0) and (thisUserDownVote == 0):
if (vote_type == 'up'):
thread.userUpVotes.add(request.user)
elif (vote_type == 'down'):
thread.userDownVotes.add(request.user)
else:
return HttpResponse('error-unknown vote type')
else:
return HttpResponse('error - already voted', thisUserUpVote, thisUserDownVote)
elif (vote_action == 'recall-vote'):
if (vote_type == 'up') and (thisUserUpVote == 1):
thread.userUpVotes.remove(request.user)
elif (vote_type == 'down') and (thisUserDownVote ==1):
thread.userDownVotes.remove(request.user)
else:
return HttpResponse('error - unknown vote type or no vote to recall')
else:
return HttpResponse('error - bad action')
num_votes = thread.userUpVotes.count() - thread.userDownVotes.count()
return HttpResponse(num_votes)
And the relevant parts of the Thread model:
class Thread(models.Model):
# ...
userUpVotes = models.ManyToManyField(User, blank=True, related_name='threadUpVotes')
userDownVotes = models.ManyToManyField(User, blank=True, related_name='threadDownVotes')
