view.py

# views.py


from django.shortcuts import get_object_or_404, render_to_response
from django.http import HttpResponseRedirect, HttpResponse
from django.core.urlresolvers import reverse
from django.template import RequestContext
from polls.models import Choice, Poll

from django.contrib.auth import authenticate, login
from django.contrib.auth import logout
from polls.models import Voter


def login_view(request,poll_id=0):
	if (request.POST):
		username = request.POST['username']
		password = request.POST['password']
		user = authenticate(username=username, password=password)
		if user is not None:
			if user.is_active:
				login(request, user)
				return HttpResponseRedirect('welcome')
			else:
				return render_to_response('polls/login.html', {'error_message': "invalid user"})
		else:
			return render_to_response('polls/login.html', {'error_message': "invalid userID and password combination"},context_instance=RequestContext(request))
	else:
		return render_to_response('polls/login.html', {'error_message': "Please enter login credentials"},context_instance=RequestContext(request))



def logout_view(request,poll_id=0):
    logout(request)
    return render_to_response('/polls/login.html', {'error_message': "successfully logged out"},context_instance=RequestContext(request))



def index(request):
    latest_poll_list = Poll.objects.all().order_by('-pub_date')[:5]
    return render_to_response('polls/index.html', {'latest_poll_list': latest_poll_list})

def detail(request, poll_id):
	p = get_object_or_404(Poll, pk=poll_id)
	voters=[u.user.id for u in Voter.objects.filter(poll__id=poll_id)]

	if request.user.id in voters:
	#	return HttpResponseRedirect(reverse('polls.views.results', kwargs={'message':'You have already voted','poll_id':p.id}))
		return render_to_response('polls/results.html',{'poll':p,'error_message':"You have already voted"})

	else:
		return render_to_response('polls/detail.html', {'poll': p},context_instance=RequestContext(request))

def results(request, poll_id, message=' '):
    p = get_object_or_404(Poll, pk=poll_id)
    return render_to_response('polls/results.html', {'poll': p,'error_message':message})

def vote(request, poll_id):
	poll = get_object_or_404(Poll, pk=poll_id)

	if not request.user.is_authenticated():
		return render_to_response('polls/detail.html',RequestContext(request,{'object': poll,'error_message': "Anonymous visitors can not vote.", }))

	voters=[u.user.id for u in Voter.objects.filter(poll__id=poll_id)]
	if request.user.id in voters:
		return render_to_response('polls/results.html',RequestContext(request,{'object': poll,'error_message': "You have already voted.",  }))

	try:
		selected_choice = poll.choice_set.get(pk=request.POST['choice'])
	except (KeyError, Choice.DoesNotExist):
        # Redisplay the poll voting form.
		return render_to_response('polls/detail.html', {
            'poll': poll,
            'error_message': "You didn't select a choice.",
        }, context_instance=RequestContext(request))
	else:
		selected_choice.votes += 1
		#request.session['has_voted_poll']=voted_polls+[poll_id]
        selected_choice.save()
        # Always return an HttpResponseRedirect after successfully dealing
        # with POST data. This prevents data from being posted twice if a
        # user hits the Back button.
		        # We save the state that a given user has voted in a given poll
        v = Voter(user=request.user,poll=poll)
        v.save()
        return HttpResponseRedirect(reverse('polls.views.results', args=(poll.id,)))