{% url %} gives me NoReverseMatch error while reverse() returns the url just fine. Why?

Question

I don't know if this SO question is of the same problem that I am about to describe, but it does share the same symptoms. Unfortunately, it still remains unresolved as I am writing.

So here is my problem. I am trying to add James Bennett's django-registration app to my django project. I have pretty much finished configuring it to my needs - custom templates and urls. Just when I thought everything was good to go. I got NoReverseMatch error from using {% url 'testing' item_id=123 %} (I also tried using the view name, myapp.views.test, instead but no luck) in one of the custom templates required by django-registration. Interestingly, I tried reverse('testing', kwargs={'item_id':123}) in the shell and the url was returned just fine. I thought {% url %} uses reverse() in the back-end but why did I get different outcomes?

urls.py: (the URLconf of my site)

urlpatterns = patterns('myapp.views',
    url(r'^test/(?P<item_id>\d+)/$', 'test', name='testing'),
)

activation_email.txt: (the said template. Note it's intentionally in .txt extension as required by django-registration and that shouldn't be the cause of the problem.)

{% comment %}Used to generate the body of the activation email.{% endcomment %}
Welcome to {{ site }}! Please activate your account by clicking on the following link:

{% url 'testing' item_id=123 %}

Note the activation link/code will be expired in {{ expiration_days }} days.

I don't know if it matters but just thought I should mention activation_email.txt is stored in the templates directory of myapp though it is used by django-registration.

Also, I am using django 1.4

I have a feeling that the problem has something to do with the url namespaces, a topic that I have never understood, but it's just a naive guess. (IMO, the django documentation is great in explaining everything about django, except when it comes to url namespaces)

Answer 1

I'm no expert here, but in a Django project I'm working on at the moment I use the name of the url without quotes. I just added quotes around a similar line in one of my templates and it produced the same error as your error.

Try:

{% url testing item_id=123 %}