Django post duplicates on page refresh - django

Question

I have this view which adds replies to a topic:
#login_required
def post_reply(request, topic_id):
tform = PostForm()
topic = Topic.objects.get(pk=topic_id)
args = {}
if request.method == 'POST':
post = PostForm(request.POST)
if post.is_valid():
p = post.save(commit = False)
p.topic = topic
p.title = post.cleaned_data['title']
p.body = post.cleaned_data['body']
p.creator = request.user
p.user_ip = request.META['REMOTE_ADDR']
p.save()
tid = int(topic_id)
args['topic_id'] = tid
args['topic'] = topic
args['posts'] = Post.objects.filter(topic_id= topic_id).order_by('created')
return render_to_response("myforum/topic.html",args)
else:
args.update(csrf(request))
args['form'] = tform
args['topic'] = topic
return render_to_response('myforum/reply.html', args,
context_instance=RequestContext(request))
The problem is that when user refershes the page after posting a reply her reply is being duplicated. How to avoid this?
UPDATE:Here is the related template:
{% extends "base.html"%}
{% load static %}
{% block content%}
<div class="panel">
<div class="container">
<!-- Posts -->
<div class="col-md-12">
<h3>{{ topic.title }}</h3>
<table class="table table-striped">
<tr class="col-md-9"><td>{{ topic.description }}</td></tr>
<tr class="col-md-3"><div class="userpanel"><td>{{ topic.created }}</td></div></tr>
{% for post in posts %}
<tr class="col-md-12 userpanel"><td>{{ post.title }}</td></tr>
<tr class="">
<td>
<div class="col-md-9 userpanel">{{ post.body }} <br> {{ post.created }} </div>
</td>
<td>
<div class="col-md-3 userpanel">{{ post.creator }} <br> {{ post.created }} </div>
</td>
</tr>
{% endfor %}
</table>
<hr />
<!-- Next/Prev page links -->
{% if posts.object_list and posts.paginator.num_pages > 1 %}
<div class="pagination">
<span class="step-links">
{% if posts.has_previous %}
previous <<
{% endif %}
<span class="current">
Page {{ posts.number }} of {{ topics.paginator.num_pages }}
</span>
{% if posts.has_next %}
>> next
{% endif %}
</span>
</div>
{% endif %}
<a class="button" href="/forum/reply/{{topic.id}}"> Reply </a>
</div> <!-- End col-md-12 -->
</div> <!-- End container -->
</div>
{% endblock %}

Answer 1

Always - I repeat, always, redirect after a POST.
So instead of doing a return render_to_response("myforum/topic.html",args) when your form is valid, do a return HttpResponseRedirect(url_of_your_view) (https://docs.djangoproject.com/en/1.7/ref/request-response/#django.http.HttpResponseRedirect)
Update after OP's comments:
You should use reverse (https://docs.djangoproject.com/en/1.7/ref/urlresolvers/#reverse) to create the url to redirect to:
return HttpResponseRedirect(reverse('myforum.views.topic', args=[topic_id]))
Also, I recommend to name your views (and drop strings for defining them since they are deprecated), so change your urls.py line like this:
from myforum.views import topic
...
url(r'^topic/(\d+)/$', topic, name='view_topic'),
...
And then just do a reverse('view_topic', args=[topic_id]) to get the url of your view.