Django named urls unrecognized by template url tags

Question

In projects/urls.py I have:

urlpatterns = patterns('bizteen.projects.views',
    url(r'^browse/$', 'browse', name='projects-browse-main'),
    url(r'^browse/(\d+)/$', 'browse', name='projects-browse'),
    url(r'^create/$', 'create', name='projects-create'),
    url(r'^(\d+)/$', 'view_project', name='projects-view'),
)

And in a template I have:

<a href="{% url projects-browse-main %}">Browse projects</a>

But an error shows up.

TemplateSyntaxError at /

Caught an exception while rendering: Reverse for 'bizteen.projects-browse-main' with arguments '()' and keyword arguments '{}' not found.

The most I can figure out is that the names are being treated like views instead. Why would this happen?

from bizteen.projects.views:

from django.shortcuts import render_to_response
from django.http import HttpResponse, HttpResponseRedirect
from bizteen.projects.models import Project, ProjectComment
from django.template import RequestContext

def browse(request, page=0):
    page_start = page * 25
    page_end = page_start + 25
    project_list = Project.objects.order_by('date_created').reverse([page_start:page_end]
    return render_to_response('browse_projects.html', {'project_list': project_list}, context_instance=RequestContext(request))

and the main urls.py:

from django.conf.urls.defaults import *

from django.contrib import admin
admin.autodiscover()

urlpatterns = patterns('',
    (r'^users/', include('bizteen.userthings.urls')),
    (r'^projects/', include('bizteen.projects.urls')),
    url(r'^$', 'bizteen.userthings.views.home', name='main-home'),

    url(r'^profile/$', 'bizteen.userthings.user-profile'),

    url(r'^admin/doc/', include('django.contrib.admindocs.urls')),
    url(r'^admin/(.*)', admin.site.root),

    url(r'^site_media/(?P<path>.*)$', 'django.views.static.serve',
        {'document_root': 'templates/static'}),
)

traceback:

Environment:

Request Method: GET
Request URL: http://127.0.0.1:8000/
Django Version: 1.0.2 final
Python Version: 2.5.1
Installed Applications:
['django.contrib.auth',
 'django.contrib.contenttypes',
 'django.contrib.sessions',
 'django.contrib.admin',
 'bizteen.userthings',
 'bizteen.projects']
Installed Middleware:
('django.middleware.common.CommonMiddleware',
 'django.contrib.sessions.middleware.SessionMiddleware',
 'django.contrib.auth.middleware.AuthenticationMiddleware')


Template error:
In template /Users/xenon/bizteen/trunk/web/bizteen/templates/base.html, error at line 33
   Caught an exception while rendering: Reverse for 'bizteen.main-home' with arguments '()' and keyword arguments '{}' not found.
   23 :         <div class="span-24"> 


   24 :                 <div class="span-10">&nbsp; </div>


   25 :                 <div class="span-8">


   26 :                     <div id='quick_user_menu'>


   27 :                         <b>Hi there!</b> 


   28 :                         {% if user.is_authenticated %}


   29 :                         <b><a href="{{ user.get_absolute_url }}">{{ user.username }}</a></b>


   30 :                             <a href='/user/home/' class='lightblue'>Dashboard</a> |  


   31 :                             (<a href='/user/logout/' class='anchor'>logout</a>)


   32 :                         {% else %}


   33 :                         <a href=' {% url main-home %} ' class='lightblue' rel='facebox'>Sign In</a> 


   34 :                         (<a href='/user/signup/'   class='anchor'>Don't have an account?</a>)


   35 :                         


   36 :                         {% endif %}


   37 :                     </div>


   38 :                 </div>


   39 :         </div>


   40 :         <div class="span-24"> 


   41 :             <div id='header'>


   42 :                 <div class="span-8">


   43 :                     <A href='/user/home/'><img src='http://localhost:8000/site_media/images/logo.png' alt='BizTeen logo image' align='left'/></a>


Traceback:
File "/Library/Python/2.5/site-packages/django/core/handlers/base.py" in get_response
  86.                 response = callback(request, *callback_args, **callback_kwargs)
File "/Users/xenon/bizteen/trunk/web/bizteen/../bizteen/userthings/views.py" in home
  29.     return render_to_response('home.html', context_instance=RequestContext(request))
File "/Library/Python/2.5/site-packages/django/shortcuts/__init__.py" in render_to_response
  18.     return HttpResponse(loader.render_to_string(*args, **kwargs), **httpresponse_kwargs)
File "/Library/Python/2.5/site-packages/django/template/loader.py" in render_to_string
  107.     return t.render(context_instance)
File "/Library/Python/2.5/site-packages/django/template/__init__.py" in render
  176.         return self.nodelist.render(context)
File "/Library/Python/2.5/site-packages/django/template/__init__.py" in render
  768.                 bits.append(self.render_node(node, context))
File "/Library/Python/2.5/site-packages/django/template/debug.py" in render_node
  71.             result = node.render(context)
File "/Library/Python/2.5/site-packages/django/template/loader_tags.py" in render
  97.         return compiled_parent.render(context)
File "/Library/Python/2.5/site-packages/django/template/__init__.py" in render
  176.         return self.nodelist.render(context)
File "/Library/Python/2.5/site-packages/django/template/__init__.py" in render
  768.                 bits.append(self.render_node(node, context))
File "/Library/Python/2.5/site-packages/django/template/debug.py" in render_node
  71.             result = node.render(context)
File "/Library/Python/2.5/site-packages/django/template/defaulttags.py" in render
  246.             return self.nodelist_false.render(context)
File "/Library/Python/2.5/site-packages/django/template/__init__.py" in render
  768.                 bits.append(self.render_node(node, context))
File "/Library/Python/2.5/site-packages/django/template/debug.py" in render_node
  81.             raise wrapped

Exception Type: TemplateSyntaxError at /
Exception Value: Caught an exception while rendering: Reverse for 'bizteen.main-home' with arguments '()' and keyword arguments '{}' not found.

Original Traceback (most recent call last):
  File "/Library/Python/2.5/site-packages/django/template/debug.py", line 71, in render_node
    result = node.render(context)
  File "/Library/Python/2.5/site-packages/django/template/defaulttags.py", line 378, in render
    args=args, kwargs=kwargs)
  File "/Library/Python/2.5/site-packages/django/core/urlresolvers.py", line 254, in reverse
    *args, **kwargs)))
  File "/Library/Python/2.5/site-packages/django/core/urlresolvers.py", line 243, in reverse
    "arguments '%s' not found." % (lookup_view, args, kwargs))
NoReverseMatch: Reverse for 'bizteen.main-home' with arguments '()' and keyword arguments '{}' not found.

Answer 1

I think it might be because

url(r'^browse/$', 'browse', name='projects-browse-main'),
url(r'^browse/(\d+)/$', 'browse', name='projects-browse'),

both refer to the same function 'browse' in 'bizteen.projects.views' but one of them takes an argument (\d+) and the other one doesn't. Have you specified a default parameter for the function? Like so

def browse(request, project="1"):

If not that, there might be a problem in your project-wide urls.py (your example looks like an excerpt from an application urls.py). Do you have something like this in your project-wide urls.py?

urlpatterns = patterns('',
    (r'^project/', include('bizteen.project.urls))
)

Answer 2

From my urls.py:

url(r'^profile/$', 'bizteen.userthings.user-profile'),

That view didn't exist. I feel dumb.

Answer 3

I personnaly import my view in my urls.py and give them as second argument of url() fonctions:

from myapp import views as myapp_views

urlpatterns = patterns('',   
   url("^myapp/blah/$", myapp_views.blah, name="myapp_blah"),
)

It avoids getting runtime errors, and allows you to add decorators like 'login_required' :

from myapp import views as myapp_views

urlpatterns = patterns('',   
   url("^myapp/blah/$", login_required(myapp_views.blah), name="myapp_blah"),
)