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.

To create an apphook place a cms_app.py in your application. And in it write the following:

from cms.app_base import CMSApp
from cms.apphook_pool import apphook_pool
from django.utils.translation import ugettext_lazy as _
class MyApphook(CMSApp):
    name = _("My Apphook")
    urls = ["myapp.urls"]
apphook_pool.register(MyApphook)

Replace myapp.urls with the path to your applications urls.py. Now edit a page and open the advanced settings tab. Select your new apphook under “Application”. Save the page.

Warning

Whenever you add or remove an apphook, change the slug of a page containing an apphook or the slug if a page which has a descendant with an apphook, you have to restart your server to re-load the URL caches.

An apphook won’t appear until it is published. Take note that this also means all parent pages must also be published.

Note

If at some point you want to remove this apphook after deleting the cms_app.py there is a cms management command called uninstall apphooks that removes the specified apphook(s) from all pages by name. eg. manage.py cms uninstall apphooks MyApphook. To find all names for uninstallable apphooks there is a command for this as well manage.py cms list apphooks.

If you attached the app to a page with the url /hello/world/ and the app has a urls.py that looks like this:

from django.conf.urls import *
urlpatterns = patterns('sampleapp.views',
    url(r'^$', 'main_view', name='app_main'),
    url(r'^sublevel/$', 'sample_view', name='app_sublevel'),
)

The main_view should now be available at /hello/world/ and the sample_view has the url /hello/world/sublevel/.

Note

CMS pages below the page to which the apphook is attached to, can be visible, provided that the apphook urlconf regexps are not too greedy. From a URL resolution perspective, attaching an apphook works in same way than inserting the apphook urlconf in the root urlconf at the same path as the page is attached to.

Note

All views that are attached like this must return a RequestContext instance instead of the default Context instance.

Apphook menus

If you want to add a menu to that page as well that may represent some views in your app add it to your apphook like this:

from myapp.menu import MyAppMenu
class MyApphook(CMSApp):
    name = _("My Apphook")
    urls = ["myapp.urls"]
    menus = [MyAppMenu]
apphook_pool.register(MyApphook)

For an example if your app has a Category model and you want this category model to be displayed in the menu when you attach the app to a page. We assume the following model:

from django.db import models
from django.core.urlresolvers import reverse
import mptt
class Category(models.Model):
    parent = models.ForeignKey('self', blank=True, null=True)
    name = models.CharField(max_length=20)
    def __unicode__(self):
        return self.name
    def get_absolute_url(self):
        return reverse('category_view', args=[self.pk])
try:
    mptt.register(Category)
except mptt.AlreadyRegistered:
    pass

We would now create a menu out of these categories:

from menus.base import NavigationNode
from menus.menu_pool import menu_pool
from django.utils.translation import ugettext_lazy as _
from cms.menu_bases import CMSAttachMenu
from myapp.models import Category
class CategoryMenu(CMSAttachMenu):
    name = _("test menu")
    def get_nodes(self, request):
        nodes = []
        for category in Category.objects.all().order_by("tree_id", "lft"):
            node = NavigationNode(
                category.name,
                category.get_absolute_url(),
                category.pk,
                category.parent_id
            )
            nodes.append(node)
        return nodes
menu_pool.register_menu(CategoryMenu)

If you add this menu now to your apphook:

from myapp.menus import CategoryMenu
class MyApphook(CMSApp):
    name = _("My Apphook")
    urls = ["myapp.urls"]
    menus = [MyAppMenu, CategoryMenu]

You get the static entries of MyAppMenu and the dynamic entries of CategoryMenu both attached to the same page.

Attaching an application multiple times

If you want to attach an application multiple times to different pages you have 2 possibilities.

1. Give every application its own namespace in the advanced settings of a page.
2. Define an app_name attribute on the CMSApp class.

The problem is that if you only define a namespace you need to have multiple templates per attached app.

For example:

{% url 'my_view' %}

Will not work anymore when you namespace an app. You will need to do something like:

{% url 'my_namespace:my_view' %}

The problem is now if you attach apps to multiple pages your namespace will change. The solution for this problem are application namespaces.

If you’d like to use application namespaces to reverse the URLs related to your app, you can assign a value to the app_name attribute of your app hook like this:

class MyNamespacedApphook(CMSApp):
    name = _("My Namespaced Apphook")
    urls = ["myapp.urls"]
    app_name = "myapp_namespace"
apphook_pool.register(MyNamespacedApphook)

Note

If you do provide an app_label, then you will need to also give the app a unique namespace in the advanced settings of the page. If you do not, and no other instance of the app exists using it, then the ‘default instance namespace’ will be automatically set for you. You can then either reverse for the namespace(to target different apps) or the app_name (to target links inside the same app).

If you use app namespace you will need to give all your view context a current_app:

def my_view(request):
    current_app = resolve(request.path_info).namespace
    context = RequestContext(request, current_app=current_app)
    return render_to_response("my_templace.html", context_instance=context)

Note

You need to set the current_app explicitly in all your view contexts as django does not allow an other way of doing this.

You can reverse namespaced apps similarly and it “knows” in which app instance it is:

{% url myapp_namespace:app_main %}

If you want to access the same url but in a different language use the language template tag:

{% load i18n %}
{% language "de" %}
    {% url myapp_namespace:app_main %}
{% endlanguage %}

Note

The official Django documentation has more details about application and instance namespaces, the current_app scope and the reversing of such URLs. You can look it up at https://docs.djangoproject.com/en/dev/topics/http/urls/#url-namespaces

When using the reverse function, the current_app has to be explicitly passed as an argument. You can do so by looking up the current_app attribute of the request instance:

def myviews(request):
    current_app = resolve(request.path_info).namespace
    reversed_url = reverse('myapp_namespace:app_main',
            current_app=current_app)
    ...

Or, if you are rendering a plugin, of the context instance:

class MyPlugin(CMSPluginBase):
    def render(self, context, instance, placeholder):
        # ...
        current_app = resolve(request.path_info).namespace
        reversed_url = reverse('myapp_namespace:app_main',
                current_app=current_app)
        # ...

Apphook permissions

By default all apphooks have the same permissions set as the page they are assigned to. So if you set login required on page the attached apphook and all it’s urls have the same requirements.

To disable this behavior set permissions = False on your apphook:

class SampleApp(CMSApp):
    name = _("Sample App")
    urls = ["project.sampleapp.urls"]
    permissions = False

If you still want some of your views to have permission checks you can enable them via a decorator:

cms.utils.decorators.cms_perms

Here is a simple example:

from cms.utils.decorators import cms_perms
@cms_perms
def my_view(request, **kw):
    ...

If you have your own permission check in your app, or just don’t want to wrap some nested apps with CMS permission decorator, then use exclude_permissions property of apphook:

class SampleApp(CMSApp):
    name = _("Sample App")
    urls = ["project.sampleapp.urls"]
    permissions = True
    exclude_permissions = ["some_nested_app"]

For example, django-oscar apphook integration needs to be used with exclude permissions of dashboard app, because it use customizable access function. So, your apphook in this case will looks like this:

class OscarApp(CMSApp):
    name = _("Oscar")
    urls = [
        patterns('', *application.urls[0])
    ]
    exclude_permissions = ['dashboard']

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 or the slug if a page which has a descendant with an apphook, you have to restart your server to re-load the URL caches. To allow you to automate this process, the django CMS provides a signal cms.signals.urls_need_reloading which you can listen on to detect when your server needs restarting. When you run manage.py runserver a restart should not be needed.

Warning

This signal does not actually do anything. To get 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.

Warning

The signal is fired after a request. If you change something via API you need a request for the signal to fire.