1. Extending the CMS: Examples

From this point onwards, this tutorial assumes you have done the Django Tutorial and will show you how to integrate the tutorial’s poll app into the django CMS. Hereafter, if a poll app is mentioned, we are referring to the one you get after completing the Django Tutorial. Also, make sure the poll app is in your INSTALLED_APPS.

We assume your main urls.py looks something like this:

from django.conf.urls.defaults import *
from django.contrib import admin
admin.autodiscover()
urlpatterns = patterns('',
    (r'^admin/', include(admin.site.urls)),
    (r'^polls/', include('polls.urls')),
    (r'^', include('cms.urls')),
)

1.1. My First Plugin

A Plugin is a small bit of content that you can place on your pages.

1.1.1. The Model

For our polling app we would like to have a small poll plugin which shows a poll and lets the user vote.

In your poll application’s models.py add the following:

from cms.models import CMSPlugin
class PollPlugin(CMSPlugin):
    poll = models.ForeignKey('polls.Poll', related_name='plugins')
    def __unicode__(self):
      return self.poll.question

Note

django CMS plugins must inherit from cms.models.CMSPlugin (or a subclass thereof) and not models.Model.

Run manage.py syncdb to create the database tables for this model or see Using South with django CMS to see how to do it using South.

1.1.2. The Plugin Class

Now create a file cms_plugins.py in the same folder your models.py is in. After having followed the Django Tutorial and adding this file your polls app folder should look like this:

polls/
    __init__.py
    cms_plugins.py
    models.py
    tests.py
    views.py

The plugin class is responsible for providing the django CMS with the necessary information to render your Plugin.

For our poll plugin, write the following plugin class:

from cms.plugin_base import CMSPluginBase
from cms.plugin_pool import plugin_pool
from polls.models import PollPlugin as PollPluginModel
from django.utils.translation import ugettext as _
class PollPlugin(CMSPluginBase):
    model = PollPluginModel # Model where data about this plugin is saved
    name = _("Poll Plugin") # Name of the plugin
    render_template = "polls/plugin.html" # template to render the plugin with
    def render(self, context, instance, placeholder):
        context.update({'instance':instance})
        return context
plugin_pool.register_plugin(PollPlugin) # register the plugin

Note

All plugin classes must inherit from cms.plugin_base.CMSPluginBase and must register themselves with the cms.plugin_pool.plugin_pool.

1.1.3. The Template

You probably noticed the render_template attribute in the above plugin class. In order for our plugin to work, that template must exist and is responsible for rendering the plugin.

The template should look something like this:

<h1>{{ instance.poll.question }}</h1>
<form action="{% url polls.views.vote instance.poll.id %}" method="post">
{% csrf_token %}
{% for choice in instance.poll.choice_set.all %}
    <input type="radio" name="choice" id="choice{{ forloop.counter }}" value="{{ choice.id }}" />
    <label for="choice{{ forloop.counter }}">{{ choice.choice }}</label><br />
{% endfor %}
<input type="submit" value="Vote" />
</form>

Note

We don’t show the errors here, because when submitting the form you’re taken off this page to the actual voting page.

1.2. My First App (apphook)

Right now, external apps are statically hooked into the main urls.py. This is not the preferred approach in the django CMS. Ideally you attach your apps to CMS pages.

For that purpose you write a CMSApp. That is just a small class telling the CMS how to include that app.

CMS Apps live in a file called cms_app.py, so go ahead and create it to make your polls app look like this:

polls/
    __init__.py
    cms_app.py
    cms_plugins.py
    models.py
    tests.py
    views.py

In this file, write:

from cms.app_base import CMSApp
from cms.apphook_pool import apphook_pool
from django.utils.translation import ugettext_lazy as _
class PollsApp(CMSApp):
    name = _("Poll App") # give your app a name, this is required
    urls = ["polls.urls"] # link your app to url configuration(s)
apphook_pool.register(PollsApp) # register your app

Now remove the inclusion of the polls urls in your main urls.py so it looks like this:

from django.conf.urls.defaults import *
from django.contrib import admin
admin.autodiscover()
urlpatterns = patterns('',
    (r'^admin/', include(admin.site.urls)),
    (r'^', include('cms.urls')),
)

Now open your admin in your browser and edit a CMS Page. Open the ‘Advanced Settings’ tab and choose ‘Polls App’ for your ‘Application’.

Unfortunately, for these changes to take effect, you will have to restart your server. So do that and afterwards if you navigate to that CMS Page, you will see your polls application.

1.3. My First Menu

Now you might have noticed that the menu tree stops at the CMS Page you created in the last step. So let’s create a menu that shows a node for each poll you have active.

For this we need a file called menu.py. Create it and ensure your polls app looks like this:

polls/
    __init__.py
    cms_app.py
    cms_plugins.py
    menu.py
    models.py
    tests.py
    views.py

In your menu.py write:

from cms.menu_bases import CMSAttachMenu
from menus.base import Menu, NavigationNode
from menus.menu_pool import menu_pool
from django.core.urlresolvers import reverse
from django.utils.translation import ugettext_lazy as _
from polls.models import Poll
class PollsMenu(CMSAttachMenu):
    name = _("Polls Menu") # give the menu a name, this is required.
    def get_nodes(self, request):
        """
        This method is used to build the menu tree.
        """
        nodes = []
        for poll in Poll.objects.all():
            # the menu tree consists of NavigationNode instances
            # Each NavigationNode takes a label as its first argument, a URL as
            # its second argument and a (for this tree) unique id as its third
            # argument.
            node = NavigationNode(
                poll.question,
                reverse('polls.views.detail', args=(poll.pk,)),
                poll.pk
            )
            nodes.append(node)
        return nodes
menu_pool.register_menu(PollsMenu) # register the menu.

At this point this menu alone doesn’t do a whole lot. We have to attach it to the Apphook first.

So open your cms_apps.py and write:

from cms.app_base import CMSApp
from cms.apphook_pool import apphook_pool
from polls.menu import PollsMenu
from django.utils.translation import ugettext_lazy as _
class PollsApp(CMSApp):
    name = _("Poll App")
    urls = ["polls.urls"]
    menus = [PollsMenu] # attach a CMSAttachMenu to this apphook.
apphook_pool.register(PollsApp)