A generic object view tracking model.

This will store a "last viewed date" which says "everything that has changed" since this date, is unread. It also stores a list of primary keys, which has been read since that date.

Install

Download and install the package using distutils:

pip install objtrack

Update your settings.py and add the installed apps settings:

INSTALLED_APPS = (
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'objtrack',
)

Finally, run python manage.py syncdb to create the database tables.

Usage

Showing forums which have new posts in them:

from objtrack.models import ObjectTracker

def view_forum_list(request):
    categories = Category.objects.all()

    tracking = ObjectTracker.objects.get_for_request(request, Thread)

    # Don't forget you still need to update a date field when a new thread
    # is added to the forum.
    for category in categories:
        category.has_new_posts = tracking.has_viewed(category)

    # Maybe we want to mark all forums as "i saw this" now?
    tracking.mark_all_as_viewed()

    return render(...)

Adding a has_viewed attribute to threads in the thread listing:

def view_thread_list(request):
    threads = Thread.objects.all()

    tracking = ObjectTracker.objects.get_for_request(request, Thread)

    # This isn't the *best* approach to checking if it's been viewed, but it works
    for thread in threads:
        thread.has_viewed = tracking.has_viewed(thread)

    return render(...)

Marking the thread object as read when it's viewed:

def view_thread(request, thread_id):
    thread = Thread.objects.get(pk=thread_id)

    tracking = ObjectTracker.objects.get_for_request(request, Thread)
    tracking.mark_as_viewed(thread)

    return render(...)

You can also use it within Coffin or Django templates:

{% load tracking %}

{% for instance, has_viewed in queryset|with_tracking(request.session, "date_field") %}
        ...
{% endfor %}