Django: Issue with url conf

Question

I'm trying to change my project to use class based views, and I'm running into a strange error with my url conf

I have a classed based view:

class GroupOrTeamCreate(AjaxableResponseMixin, CreateView):
    model = GroupOrTeam
    fields = ['name', 'description']
    #success_url = reverse('home_page')  # redirect to self

I have the last line commented out because if I don't, django complains that there are no patterns in my url conf.

To start, here's my base urls.py

urlpatterns = patterns('',
    url(r'^$', TemplateView.as_view(template_name='core/home.html'), name='home_page'),
    url(r'^administration/', include('administration.urls', app_name='administration')),
    url(r'^reports/', include('reports.urls', app_name='reports')),
    url(r'^admin/doc/', include('django.contrib.admindocs.urls')),
    url(r'^admin/', include(admin.site.urls)),
)

Clearly there are patterns in there. If I comment out the administration urls, it works. So I assume the problem is in there somewhere.

administration urls.py

from django.conf.urls import patterns, url
from .views import ActiveTabTemplateView, GroupOrTeamCreate, GroupOrTeamUpdate


urlpatterns = patterns('',

    # Add page
    url(r'^add/$', ActiveTabTemplateView.as_view(template_name='administration/add.html'), name='add_page'),
    url(r'^add/(?P<active_tab>\w+)/$', ActiveTabTemplateView.as_view(template_name='administration/add.html'),
    name='add_page'),

    # Seach page
    url(r'^search/$', ActiveTabTemplateView.as_view(template_name='administration/search.html'), name='search_page'),
    url(r'^search/(?P<active_tab>\w+)/$', ActiveTabTemplateView.as_view(template_name='administration/search.html'),
    name='search_page'),

    #--------------------------------------------------------------------------
    # Forms
    #--------------------------------------------------------------------------

    # Groups and teams
    url(r'^group-or-team-form/$', GroupOrTeamCreate.as_view(template_name='administration/forms/groups_form.html'),
        name='group_or_team_form'),
    url(r'^group-or-team-form/(?P<pk>\d+)/$',
        GroupOrTeamUpdate.as_view(template_name='administration/forms/groups_form.html'),
        name='group_or_team_form'),

)

I'm not seeing the problem.. these pages load just fine without that reverse statement in, it appears to be the introduction of the reverse statement that breaks everything but I can't for the life of me work out what the cause is.

Answer 1

You get the error because the URL conf has not been loaded yet when the class is defined.

Use reverse_lazy instead of reverse.

from django.core.urlresolvers import reverse_lazy

success_url = reverse_lazy('home_page')