Django NoReverseMatch and Blank Page - django

Question

I am using Django 1.4.5.
I get an error when I access the detail of entry via admin's page.
"NoReverseMatch at /admin/r/12/1/": Reverse for 'detail' with
arguments '()' and keyword arguments '{'category': u'category',
'slug': u'entry-test'}' not found
And get nothing/blank page when access the detail of entry on front's page (/category/entry-test/).
And what's the right of models & URLname pattern if I want to access the entry detail via sub-category (/category/subcategory/entry-test/)?
Model snippet:
class Entry (models.Model):
title = models.CharField()
slug = models.SlugField()
category = models.ForeignKey('entry.Category')
def __unicode__(self):
return self.title
#models.permalink
def get_absolute_url(self):
return ('entry.views.detail', (), {'category': self.category.slug, 'slug': self.slug})
def save(self, *args, **kwargs):
if not self.slug:
self.slug = slugify(self.title)
return super(Entry, self).save(*args, **kwargs)
class Category(models.Model):
title = models.CharField()
slug = models.SlugField()
parent = models.ForeignKey('self', blank=True, null=True, related_name='children')
def __unicode__(self):
if self.parent:
return self.parent.title, self.title
return self.title
#permalink
def get_absolute_url(self):
return ('entry.views.category', (), {'slug': self.slug})
Views snippet:
def category(request):
category = Category.objects.all()
return render_to_response('category.html', locals(), context_instance=RequestContext(request))
def list(request, slug_id):
category = get_object_or_404(Category, slug=slug_id)
list = Entry.objects.filter(category=category)
return render_to_response("list.html", locals(), context_instance=RequestContext(request))
def detail(request, category_id, slug_id):
entry = Entry.objects.filter(slug=slug_id)
category = Category.objects.filter(slug=category_id)
return render_to_response('detail.html', locals(), context_instance=RequestContext(request))
URLs snippet:
urlpatterns = patterns('entry.views',
(r'^$', 'category', name='entry-category'),
url(r'^(?P<slug_id>[-\w]+)/$', 'list', name='entry-list'),
url(r'^(?P<category_id>[-\w]+)/(?P<slug_id>[-\w]+)/$', 'detail', name='entry-detail'),
Template snippet:
category.html
<ul>
{% for category in category %}
<li>{{ category.title }} ({{ category.entry_set.all.count }})</li>
{% endfor %}
</ul>
list.html
<ul>
{% for entry in list %}
<li>{{ entry.title }}</li>
{% endfor %}
</ul>
detail.html
<ul>
{% for entry in entry.category %}
<li>{{ entry.title }}
<br />{{ entry.description }}</li>
{% endfor %}
</ul>
Where and what I could be doing wrong?
If any one can help I'd appreciate it! Please help me.

Answer 1

Your keyword arguments for the url are category_id and slug_id, but you are passing in category and slug in your get_absolute_url method. This version should work:
#models.permalink
def get_absolute_url(self):
return ('entry.views.detail',
(), {'category_id': self.category.slug, 'slug_id': self.slug})
Also consider renaming your arguments. id is generally numeric and slug is alphanumeric.
For your blank page problem (from your comment):
Your URL /category/entry-test/ - this will map to your detail view if the snippet your pasted in your question is in your main urls.py. If you have no matching results (the .filter() call has no results), you'll see a "blank" page, because the <ul> will not have any li elements.
If in your main urls.py, you have something like url('^category/', include(some.other.urls)), then the URL will map to your list view, and you have the same issue - the .filter() is not returning any results, and hence you see a "blank" page.

Answer 2

I do little mistake on detail template:
<ul>
{% for entry in entry %}
<li>
{{ entry.title }}
<br />
{{ entry.description }}
</li>
{% endfor %}
</ul>
The problem is solved now.