Tumblelog
This is how to create a tumblelog with Django. It consist of display chrnologicaly the last things that happened on your blog : articles, photos, music, every thing you desire !
The mechanism is based on Django’s content types, we are going to associate a generic object call LogItem with an other object less generic like a article (Post) or a photo (Photo) for example.
Here, we are only going to display the latest articles and photos created.
Models
The LogItem object is a simple and generic object that point to an article or a photo. See for yourself :
- content_type : this will help us find out the class of the linked object.
- object_id : the id of the linked object.
- pub_date : the publication date to ease the sorting.
It easy to understand that if we have the class and the id of the linked object, we can easily instanciate it. This is what our get_content_object method is here to do :
def get_content_object(self):
from django.core.exceptions import ObjectDoesNotExist
try:
return self.content_type.get_object_for_this_type(pk=self.object_id)
except ObjectDoesNotExist:
return None
You will need to change the delete method of the object you link to delete the LogItem that are associated to them :
def delete(self):
from cyberdelia.tumblelog.models import LogItem
try:
log = LogItem.objects.get(object_id=self.id, content_type=ContentType.objects.get_for_model(self))
log.delete()
except LogItem.DoesNotExist:
pass
super(Post, self).delete()
Download the models.
Views
Nothing to complicated here, a simple generic view to display the latest 15 elements, for the details see the recommendations tutorial.
Download the urls.py.
Templates
The template receive a list of LogItem object call object_list, we just need to display them now. To find out the type of the object, we juste need to make a comparison :
{% ifequal item.content_type.name "post" %}
Then, we just need to display the specific informatiosn for the article or the photo associated. We access to the object via the get_content_object method.
Download the template.
And now ?!
We just need to feed the monster with fresh data ! We can’t update data at each load of the page, that will cost you a lot of ressources and will be pretty much useless, we are jsut going to use a goold old script that cron with launch every 15 minutes…
Our cron configuration will look like that (if you want to launch it every 15 minutes) :
*/15 * * * * www-data python /var/www/cyberdelia/tumblelog/bin/update.py --settings="cyberdelia.settings"
This script will serach for last articles and photos published and will create LogItem that link to them if they didn’t already exists.
Download this script.
