Django Vote Up/Down method

Question

I am making a small app that lets users vote items either up or down. I'm using Django (and new to it!).

I am just wondering, what is the best way to present the upvote link to the user. As a link, button or something else?

I have already done something like this in php with a different framework but I'm not sure if I can do it the same way. Should I have a method for up/down vote and then display a link to the user to click. When they click it, it performs the method and refreshes the page?

Answer 1

Whatever you do, make sure that it's submitted by POST and not GET; GET requests should never alter database information.

Answer 2

Just plug and play:

RedditStyleVoting  
Implementing reddit style voting for any Model with django-voting
http://code.google.com/p/django-voting/wiki/RedditStyleVoting

Answer 3

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')