django-follow

django-follow enables your users to follow any model in your Django application.

Installation:

pip install django-follow

Usage:

• Add follow to your INSTALLED_APPS

• Include follow.urls into your URLs if you plan on using the views:

  urlpatterns = patterns('',
      url('^', include('follow.urls')),
  )
  

• Register the models you want to be able to follow in your models.py files:

  from django.db import models
  from follow import utils
  
  class MyModel(models.Model):
      field = models.CharField(max_length = 255)
  
  
  utils.register(MyModel)
  

NOTE You must register your models before running syncdb or you will run into the issue described in django-follow/issues/16

Test

The repository includes a sample project and application that is configured to test django-follow.

Clone the repository and cd into the project folder:

cd example/
python manage.py test follow

API

Manager

• Follow.objects.create(user, obj, **kwargs):
  Makes user follow obj

• Follow.objects.get_or_create(user, obj, **kwargs):
  Returns a tuple (Follow, bool)

• Follow.objects.is_following(user, obj):
  Returns bool

• Follow.objects.get_follows(model_or_object_or_queryset):
  Returns all the Follow objects associated with a certain model, object or queryset.

Note on performance

I advise against against using Follow.objects.is_following too often in one request / response cycle on single objects. Use it on querysets to avoid stacking up too many queries.

Utils

• follow.utils.register(model, field_name, related_name, lookup_method_name):
  Registers model to django-follow.

• follow.utils.follow(user, object):
  Makes user follow object

• follow.utils.unfollow(user, object):
  Makes user unfollow object

• follow.utils.toggle(user, object):
  Toggles user's follow status of object

• follow.utils.follow_url(user, object):
  Returns the right follow/unfollow URL for user and object

• follow.utils.follow_link(object):
  Returns the following URL for object

• follow.utils.unfollow_link(object):
  Returns the unfollowing URL for object

Template Tags

django-follow ships a template tag that creates urls, a filter to check if a user follows an object and a template tag to render the follow form.

{% load follow_tags %}
{% follow_url object %}
{% request.user|is_following:object %}
{% follow_form object %}
{% follow_form object "your/custom/template.html" %}

• {% follow_url object %}:
  Returns the URL to either follow or unfollow the object, depending on whether request.user is already following the object.

• {% follow_url object other_user %}:
  Same as above - but instead of resolving for request.user it resolves for any user you pass in.

• {% request.user|is_following:object %}:
  Returns True/False if the user follows / does not follow the object.

• {% follow_form object %}:
  Renders a form to follow a given object.

• `{% follow_form object "your/custom/template.html" %}:
  Renders the form with a custom template.

Signals

django-follow provides two signals:

• follow.signals.followed(sender, user, target, instance)
• follow.signals.unfollowed(sender, user, target, instance)

To invoke a handler every time a User or Group object is followed, do something along these lines:

from django.contrib.auth.models import User
from follow import signals

def user_follow_handler(user, target, instance, **kwargs):
    send_mail("You were followed", "You have been followed", "no-reply@localhost", [target.email])

def group_follow_handler(user, target, instance, **kwargs):
    send_mail("Group followed", "%s has followed your group" % user, "no-reply@localhost", [[u.email for u in target.user_set.all()]])

signals.followed.connect(user_follow_handler, sender = User, dispatch_uid = 'follow.user')
signals.followed.connect(group_follow_handler, sender = Group, dispatch_uid = 'follow.group')

This works vica versa with the unfollowed handler too.

NOTE

When handling follow.signals.unfollowed both user and/or target can be None. Django's admin for example will first delete the user resulting in instance.user to throw DoesNotExist. Beware.

Release Notes

v0.5 - BACKWARDS INCOMPATIBLE

• The follow and unfollow views now only accept POST requests

v0.4 - BACKWARDS INCOMPATIBLE

• Made the manager a lot lighter.
• Removed Model.followers method
• Added Model.get_follows method returning all the Follow objects
• Moved Follow.follower to Follow.user
• Replaced Follow.get_object method with read/writable Follow.target property
• follow.util moved to follow.utils
• No more M2M following

@flashingpumpkin