How to pass url parameter to reverse_lazy in Django urls.py

Question

Consider that I have 1 resource and 2 urls (let's say new one and old one) connected to that resourse. So, i want to setup HTTP redirection for one of urls.

In myapp/urls.py I have:

urlpatterns = patterns('',     url(r'^(?P<param>\d+)/resource$',                        'myapp.views.resource',                         name='resource-view'     ), ) 

In mycoolapp/urls.py I want to specify:

from django.views.generic.simple import redirect_to from django.core.urlresolvers import reverse_lazy  urlpatterns = patterns('',     url(r'^coolresource/(?P<param>\d+)/$',                         redirect_to,                         {                           'url': reverse_lazy('resourse-view',                                           kwargs={'param': <???>},                                           current_app='myapp'                                  ),                        }    ), ) 

The question is how to pass <param> to the reverse_lazy kwargs (so, what to put instead of <???> in the example above)?

Answer 1

I wouldn't do this directly in the urls.py, I'd instead use the class-based RedirectView to calculate the view to redirect to:

from django.views.generic.base import RedirectView from django.core.urlresolvers import reverse_lazy  class RedirectSomewhere(RedirectView):     def get_redirect_url(self, param):         return reverse_lazy('resource-view',                             kwargs={'param': param},                             current_app='myapp') 

Then, in your urls.py you can do this:

urlpatterns = patterns('',     url(r'^coolresource/(?P<param>\d+)/$',          RedirectSomewhere.as_view()), ) 

Answer 2

Redirect View is great if you are using a hard coded url, it replaced redirect_to which is now deprecated. I don't think you can use it when redirecting and reversing from urls.py. Here is my solution, x is the response object in this case:

from django.core.urlresolvers import reverse from django.http import HttpResponseRedirect urlpatterns = patterns('',     ....     url(r'^coolresource/(?P<param>\d+)/$',                          lambda x, param: HttpResponseRedirect(                              reverse('myapp.views.resource', args=[param])                          ),                          name='resource-view-redirect'),     .... ) 

You can still use the name of the url pattern instead of a hard coded url with this solution. The location_id parameter from the url is passed down to the lambda function.