How to create apphooks¶
An apphook allows you to attach a Django application to a page. For example, you might have a news application that you’d like integrated with django CMS. In this case, you can create a normal django CMS page without any content of its own, and attach the news application to the page; the news application’s content will be delivered at the page’s URL.
All URLs in that URL path will be passed to the attached application’s URL configs.
The basics of apphook creation¶
To create an apphook, create a
cms_apps.py file in your application.
The file needs to contain a
CMSApp sub-class. For example:
from cms.app_base import CMSApp from cms.apphook_pool import apphook_pool @apphook_pool.register class MyApphook(CMSApp): app_name = "myapp" # must match the application namespace name = "My Apphook" def get_urls(self, page=None, language=None, **kwargs): return ["myapp.urls"] # replace this with the path to your application's URLs module
Changed in version 3.3:
urls was removed
in version 3.5.
Apphooks for namespaced applications¶
Your application should use namespaced URLs.
In the example above, the application uses the
myapp namespace. Your
sub-class must reflect the application’s namespace in the
The application may specify a namespace by supplying an
app_name in its
urls.py, or its
documentation might advise that you when include its URLs, you do it thus:
re_path(r'^myapp/', include('myapp.urls', app_name='myapp'))
If you fail to do this, then any templates in the application that invoke URLs using the form
'myapp:index' %} or views that call (for example)
reverse('myapp:index') will throw a
Apphooks for non-namespaced applications¶
If you are writing apphooks for third-party applications, you may find one that in fact does not have an application namespace for its URLs. Such an application is liable to tun into namespace conflicts, and doesn’t represent good practice.
However if you do encounter such an application, your own apphook for it will need in turn to forgo the
Note that unlike apphooks without
app_name attributes can be attached only to one page at a
time; attempting to apply them a second time will cause an error. Only one instance of these
apphooks can exist.
See Attaching an application multiple times for more on having multiple apphook instances.
Returning apphook URLs manually¶
Instead of defining the URL patterns in another file
myapp/urls.py, it also is possible
to return them manually, for example if you need to override the set provided. An example:
from django.urls import re_path from myapp.views import SomeListView, SomeDetailView class MyApphook(CMSApp): # ... def get_urls(self, page=None, language=None, **kwargs): return [ re_path(r'^$', SomeListView.as_view()), re_path(r'^(?P<slug>[\w-]+)/?$', SomeDetailView.as_view()), ]
However, it’s much neater to keep them in the application’s
urls.py, where they can easily be
Loading new and re-configured apphooks¶
Certain apphook-related changes require server restarts in order to be loaded.
add or remove an apphook
change the slug of a page containing an apphook or the slug of a page which has a descendant with an apphook
the URL caches must be reloaded.
If you have the cms.middleware.utils.ApphookReloadMiddleware installed, which is recommended, the server will do it for you by re-initialising the URL patterns automatically.
Otherwise, you will need to restart the server manually.
Using an apphook¶
Once your apphook has been set up and loaded, you’ll now be able to select the Application that’s hooked into that page from its Advanced settings.
An apphook won’t actually do anything until the page it belongs to is published. Take note that this also means all parent pages must also be published.
The apphook attaches all of the apphooked application’s URLs to the page; its root URL will be the page’s own URL, and any lower-level URLs will be on the same URL path.
So, given an application with the
urls.py for the views
urlpatterns = [ re_path(r'^$', index_view), re_path(r'^archive/$', archive_view), ]
attached to a page whose URL path is
/hello/world/, the views will be exposed as follows:
Sub-pages of an apphooked page¶
Don’t add child pages to a page with an apphook.
The apphook “swallows” all URLs below that of the page, handing them over to the attached application. If you have any child pages of the apphooked page, django CMS will not be able to serve them reliably.
Uninstalling an apphook with applied instances¶
If you remove an apphook class from your system (in effect uninstalling it) that still has instances applied to pages, django CMS tries to handle this as gracefully as possible:
Affected pages still maintain a record of the applied apphook; if the apphook class is subsequently reinstated, it will work as before.
The page list will show apphook indicators where appropriate.
The page will otherwise behave like a normal django CMS page, and display its placeholders in the usual way.
If you save the page’s Advanced settings, the apphook will be removed.
You can clear uninstalled apphook instances using the CMS management command
uninstall apphooks. For example:
manage.py cms uninstall apphooks MyApphook MyOtherApphook
You can get a list of installed apphooks using the cms list; in this case:
manage.py cms list apphooks
See the Management commands reference for more information.
Managing permissions on apphooks¶
By default the content represented by an apphook has the same permissions set as the page it is assigned to. So if for example a page requires the user to be logged in, then the attached apphook and all its URLs will have the same requirements.
To disable this behaviour set
permissions = False on your apphook:
class MyApphook(CMSApp): [...] permissions = False
If you still want some of your views to use the CMS’s permission checks you can enable them via a decorator,
Here is a simple example:
from cms.utils.decorators import cms_perms @cms_perms def my_view(request, **kw): ...
If you make your own permission checks in your application, then use the
exclude_permissions property of the apphook:
class MyApphook(CMSApp): [...] permissions = True exclude_permissions = ["some_nested_app"]
where you provide the name of the application in question
Automatically restart server on apphook changes¶
As mentioned above, whenever you:
add or remove an apphook
change the slug of a page containing an apphook
change the slug of a page with a descendant with an apphook
The CMS the server will reload its URL caches. It does this by listening for
This signal does not actually do anything itself. For automated server restarting you need to implement logic in your project that gets executed whenever this signal is fired. Because there are many ways of deploying Django applications, there is no way we can provide a generic solution for this problem that will always work.
The signal is fired after a request - for example, upon saving a page’s settings. If you change and apphook’s setting via an API the signal won’t fire until a subsequent request.