/django/contrib/contenttypes/views.py

 1from django import http
 2from django.contrib.contenttypes.models import ContentType
 3from django.contrib.sites.models import Site, get_current_site
 4from django.core.exceptions import ObjectDoesNotExist
 5
 6def 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        if not content_type.model_class():
12            raise http.Http404("Content type %s object has no associated model" % content_type_id)
13        obj = content_type.get_object_for_this_type(pk=object_id)
14    except (ObjectDoesNotExist, ValueError):
15        raise http.Http404("Content type %s object %s doesn't exist" % (content_type_id, object_id))
16    try:
17        absurl = obj.get_absolute_url()
18    except AttributeError:
19        raise http.Http404("%s objects don't have get_absolute_url() methods" % content_type.name)
20
21    # Try to figure out the object's domain, so we can do a cross-site redirect
22    # if necessary.
23
24    # If the object actually defines a domain, we're done.
25    if absurl.startswith('http://') or absurl.startswith('https://'):
26        return http.HttpResponseRedirect(absurl)
27
28    # Otherwise, we need to introspect the object's relationships for a
29    # relation to the Site object
30    object_domain = None
31
32    if Site._meta.installed:
33        opts = obj._meta
34
35        # First, look for an many-to-many relationship to Site.
36        for field in opts.many_to_many:
37            if field.rel.to is Site:
38                try:
39                    # Caveat: In the case of multiple related Sites, this just
40                    # selects the *first* one, which is arbitrary.
41                    object_domain = getattr(obj, field.name).all()[0].domain
42                except IndexError:
43                    pass
44                if object_domain is not None:
45                    break
46
47        # Next, look for a many-to-one relationship to Site.
48        if object_domain is None:
49            for field in obj._meta.fields:
50                if field.rel and field.rel.to is Site:
51                    try:
52                        object_domain = getattr(obj, field.name).domain
53                    except Site.DoesNotExist:
54                        pass
55                    if object_domain is not None:
56                        break
57
58    # Fall back to the current site (if possible).
59    if object_domain is None:
60        try:
61            object_domain = get_current_site(request).domain
62        except Site.DoesNotExist:
63            pass
64
65    # If all that malarkey found an object domain, use it. Otherwise, fall back
66    # to whatever get_absolute_url() returned.
67    if object_domain is not None:
68        protocol = request.is_secure() and 'https' or 'http'
69        return http.HttpResponseRedirect('%s://%s%s' % (protocol, object_domain, absurl))
70    else:
71        return http.HttpResponseRedirect(absurl)