1 from django import http

     2 from django.contrib.contenttypes.models import ContentType

     3 from django.contrib.sites.models import Site

     4 from django.core.exceptions import ObjectDoesNotExist

     5 

     6 def shortcut(request, content_type_id, object_id):

     7     "Redirect to an object's page based on a content-type ID and an object ID."

     8     # Look up the object, making sure it's got a get_absolute_url() function.

     9     try:

    10         content_type = ContentType.objects.get(pk=content_type_id)

    11         obj = content_type.get_object_for_this_type(pk=object_id)

    12     except ObjectDoesNotExist:

    13         raise http.Http404("Content type %s object %s doesn't exist" % (content_type_id, object_id))

    14     try:

    15         absurl = obj.get_absolute_url()

    16     except AttributeError:

    17         raise http.Http404("%s objects don't have get_absolute_url() methods" % content_type.name)

    18 

    19     # Try to figure out the object's domain, so we can do a cross-site redirect

    20     # if necessary.

    21 

    22     # If the object actually defines a domain, we're done.

    23     if absurl.startswith('http://') or absurl.startswith('https://'):

    24         return http.HttpResponseRedirect(absurl)

    25 

    26     # Otherwise, we need to introspect the object's relationships for a

    27     # relation to the Site object

    28     object_domain = None

    29     opts = obj._meta

    30 

    31     # First, look for an many-to-many relationship to Site.

    32     for field in opts.many_to_many:

    33         if field.rel.to is Site:

    34             try:

    35                 # Caveat: In the case of multiple related Sites, this just

    36                 # selects the *first* one, which is arbitrary.

    37                 object_domain = getattr(obj, field.name).all()[0].domain

    38             except IndexError:

    39                 pass

    40             if object_domain is not None:

    41                 break

    42 

    43     # Next, look for a many-to-one relationship to Site.

    44     if object_domain is None:

    45         for field in obj._meta.fields:

    46             if field.rel and field.rel.to is Site:

    47                 try:

    48                     object_domain = getattr(obj, field.name).domain

    49                 except Site.DoesNotExist:

    50                     pass

    51                 if object_domain is not None:

    52                     break

    53 

    54     # Fall back to the current site (if possible).

    55     if object_domain is None:

    56         try:

    57             object_domain = Site.objects.get_current().domain

    58         except Site.DoesNotExist:

    59             pass

    60 

    61     # If all that malarkey found an object domain, use it. Otherwise, fall back

    62     # to whatever get_absolute_url() returned.

    63     if object_domain is not None:

    64         protocol = request.is_secure() and 'https' or 'http'

    65         return http.HttpResponseRedirect('%s://%s%s' % (protocol, object_domain, absurl))

    66     else:

    67         return http.HttpResponseRedirect(absurl)