Django {% regroup %} produces duplicate groups - django

Question

I've defined the following models:
class Topic(models.Model):
class Meta:
ordering = [
'title']
objects = models.Manager()
highlighted = HighlightedTopicManager()
highlight = models.BooleanField(
default=False,
help_text='Show this topic on the home page?',
db_index=True)
highlight_order = models.PositiveSmallIntegerField(
default=0,
help_text='In what order do you want this to be added on the home page?'\
' Leave blank for alphabetic order.',
db_index=True)
title = models.CharField(
max_length=2048,
db_index=True)
slug = models.SlugField(
max_length=128,
db_index=True)
excerpt = models.TextField(
null=True,
blank=True)
description = models.TextField()
def _get_content(self):
if self.excerpt:
return self.excerpt
return self.description
content = property(_get_content)
#models.permalink
def get_absolute_url(self):
return ('academic_projects_topic_detail', (), {'slug': self.slug})
def __unicode__(self):
return self.title
class Project(models.Model):
class Meta:
ordering = [
'topic',
'modified',
'created']
objects = models.Manager()
highlighted = HighlightedProjectManager()
highlight = models.BooleanField(
help_text='Highlight this in the projects\' main page?'\
' Only the most recently modified one will be displayed.')
redirect_to = models.URLField(
blank=True,
null=True,
help_text='Use this for old or extenal projects.')
short_title = models.CharField(
max_length=1024,
db_index=True)
slug = models.SlugField(
max_length=128,
db_index=True)
title = models.CharField(
max_length=2048,
db_index=True)
created = models.DateTimeField(
auto_now_add=True)
modified = models.DateTimeField(
auto_now=True)
excerpt = models.CharField(
max_length=1024,
null=True,
blank=True,
help_text='Concise description to show in the listing page.')
description = models.TextField(
null=True,
blank=True,
help_text='This content will be rendered right after the title.')
downloads = models.ManyToManyField(
Download,
null=True,
blank=True,
help_text='Downloadable files')
footer = models.TextField(
null=True,
blank=True,
help_text='This content will be rendered at the bottom of the page.')
people = models.ManyToManyField(
Person,
help_text='People involved in this project.',
related_name='projects')
organizations = models.ManyToManyField(
Organization,
help_text='Organizations involved other than the lab.',
blank=True,
null=True,
related_name='projects')
publications = models.ManyToManyField(
Publication,
blank=True,
null=True)
topic = models.ForeignKey(
Topic,
verbose_name=_('Main topic'),
help_text='This is the main topic.',
related_name='projects')
sponsors = models.ManyToManyField(
Sponsor,
blank=True,
null=True,
help_text='sponsored_projects')
related_topics = models.ManyToManyField(
Topic,
null=True,
blank=True,
help_text='Optional related topics.',
related_name='secondary_projects')
def __unicode__(self):
return self.short_title
#models.permalink
def get_absolute_url(self):
return ('academic_projects_project_detail', (), {'slug': self.slug})
And use the following template to produce this page (http://seclab.cs.ucsb.edu/academic/projects/):
{% extends "academic/project_base.html" %}
{% block content_title %}Projects{% endblock %}
{% block title %}Projects - {{block.super}}{% endblock %}
{% block content %}
{% regroup object_list|dictsort:"topic" by topic as topic_list %}
{% for topic in topic_list %}
<h2 id="{{ topic.grouper.slug }}">{{ topic.grouper }} #</h2>
{% for project in topic.list %}
<h3>{{ project }}</h3>
<p>{{ project.title }}</p>
{% endfor %}
{% endfor %}
{% endblock %}
The view behind this is a generic one, and invoked as:
url(r'^$',
cache_page(ListView.as_view(
queryset=Project.objects.order_by('topic'),
template_name='academic/project_list.html')),
name='academic_projects_project_list'),
So, Projects are already sorted by Topic. Unfortunately, this code yields to duplicate gorups and, sometimes, the groups change at each refresh (or, at least, they change when I reboot the server).
Any idea of why is this happening? The entire code, besides templates', resides here: https://bitbucket.org/phretor/django-academic/src/

Answer 1

The dictsort filter is only for lists of dicts, you don't need it at all here. Your template should read
{% regroup object_list by topic as topic_list %}