zapier/django-rest-hooks

### settings.py ###

INSTALLED_APPS = (
    # other apps here...
    'rest_hooks',
)

HOOK_EVENTS = {
    # 'any.event.name': 'App.Model.Action' (created/updated/deleted)
    'book.added':       'bookstore.Book.created',
    'book.changed':     'bookstore.Book.updated+',
    'book.removed':     'bookstore.Book.deleted',
    # and custom events, no extra meta data needed
    'book.read':         'bookstore.Book.read',
    'user.logged_in':    None
}

### bookstore/models.py ###

class Book(models.Model):
    # NOTE: it is important to have a user property
    # as we use it to help find and trigger each Hook
    # which is specific to users. If you want a Hook to
    # be triggered for all users, add '+' to built-in Hooks
    # or pass user_override=False for custom_hook events
    user = models.ForeignKey('auth.User', on_delete=models.CASCADE)
    # maybe user is off a related object, so try...
    # user = property(lambda self: self.intermediary.user)

    title = models.CharField(max_length=128)
    pages = models.PositiveIntegerField()
    fiction = models.BooleanField()

    # ... other fields here ...

    def serialize_hook(self, hook):
        # optional, there are serialization defaults
        # we recommend always sending the Hook
        # metadata along for the ride as well
        return {
            'hook': hook.dict(),
            'data': {
                'id': self.id,
                'title': self.title,
                'pages': self.pages,
                'fiction': self.fiction,
                # ... other fields here ...
            }
        }

    def mark_as_read(self):
        # models can also have custom defined events
        from rest_hooks.signals import hook_event
        hook_event.send(
            sender=self.__class__,
            action='read',
            instance=self # the Book object
        )

>>> from django.contrib.auth.models import User
>>> from rest_hooks.models import Hook
>>> jrrtolkien = User.objects.create(username='jrrtolkien')
>>> hook = Hook(user=jrrtolkien,
                event='book.added',
                target='http://example.com/target.php')
>>> hook.save()     # creates the hook and stores it for later...
>>> from bookstore.models import Book
>>> book = Book(user=jrrtolkien,
                title='The Two Towers',
                pages=327,
                fiction=True)
>>> book.save()     # fires off 'bookstore.Book.created' hook automatically
...

...
>>> book.title += ': Deluxe Edition'
>>> book.pages = 352
>>> book.save()     # would fire off 'bookstore.Book.updated' hook automatically
>>> book.delete()   # would fire off 'bookstore.Book.deleted' hook automatically

from rest_hooks.signals import raw_hook_event

user = User.objects.get(id=123)
raw_hook_event.send(
    sender=None,
    event_name='user.logged_in',
    payload={
        'username': user.username,
        'email': user.email,
        'when': datetime.datetime.now().isoformat()
    },
    user=user # required: used to filter Hooks
)

### resources.py ###

from tastypie.resources import ModelResource
from tastypie.authentication import ApiKeyAuthentication
from tastypie.authorization import Authorization
from rest_hooks.models import Hook

class HookResource(ModelResource):
    def obj_create(self, bundle, request=None, **kwargs):
        return super(HookResource, self).obj_create(bundle,
                                                    request,
                                                    user=request.user)

    def apply_authorization_limits(self, request, object_list):
        return object_list.filter(user=request.user)

    class Meta:
        resource_name = 'hooks'
        queryset = Hook.objects.all()
        authentication = ApiKeyAuthentication()
        authorization = Authorization()
        allowed_methods = ['get', 'post', 'delete']
        fields = ['event', 'target']

### urls.py ###

from tastypie.api import Api

v1_api = Api(api_name='v1')
v1_api.register(HookResource())

urlpatterns = patterns('',
    (r'^api/', include(v1_api.urls)),
)

### serializers.py ###

from django.conf import settings
from rest_framework import serializers, exceptions

from rest_hooks.models import Hook


class HookSerializer(serializers.ModelSerializer):
    def validate_event(self, event):
        if event not in settings.HOOK_EVENTS:
            err_msg = "Unexpected event {}".format(event)
            raise exceptions.ValidationError(detail=err_msg, code=400)
        return event    
    
    class Meta:
        model = Hook
        fields = '__all__'
        read_only_fields = ('user',)

### views.py ###

from rest_framework import viewsets

from rest_hooks.models import Hook

from .serializers import HookSerializer


class HookViewSet(viewsets.ModelViewSet):
    """
    Retrieve, create, update or destroy webhooks.
    """
    queryset = Hook.objects.all()
    model = Hook
    serializer_class = HookSerializer

    def perform_create(self, serializer):
        serializer.save(user=self.request.user)

### urls.py ###

from rest_framework import routers

from . import views

router = routers.SimpleRouter(trailing_slash=False)
router.register(r'webhooks', views.HookViewSet, 'webhook')

urlpatterns = router.urls

### settings.py ###

HOOK_DELIVERER = 'path.to.tasks.deliver_hook_wrapper'


### tasks.py ###

from celery.task import Task

import json
import requests


class DeliverHook(Task):
    max_retries = 5

    def run(self, target, payload, instance_id=None, hook_id=None, **kwargs):
        """
        target:     the url to receive the payload.
        payload:    a python primitive data structure
        instance_id:   a possibly None "trigger" instance ID
        hook_id:       the ID of defining Hook object
        """
        try:
            response = requests.post(
                url=target,
                data=json.dumps(payload),
                headers={'Content-Type': 'application/json'}
            )
            if response.status_code >= 500:
                response.raise_for_status()
        except requests.ConnectionError:
            delay_in_seconds = 2 ** self.request.retries
            self.retry(countdown=delay_in_seconds)


def deliver_hook_wrapper(target, payload, instance, hook):
    # instance is None if using custom event, not built-in
    if instance is not None:
        instance_id = instance.id
    else:
        instance_id = None
    # pass ID's not objects because using pickle for objects is a bad thing
    kwargs = dict(target=target, payload=payload,
                  instance_id=instance_id, hook_id=hook.id)
    DeliverHook.apply_async(kwargs=kwargs)

### settings.py ###

HOOK_CUSTOM_MODEL = 'path.to.models.CustomHook'

### models.py ###

from django.db import models
from rest_hooks.models import AbstractHook

class CustomHook(AbstractHook):
    is_active = models.BooleanField(default=True)

### settings.py ###

HOOK_FINDER = 'path.to.find_and_fire_hook'

### utils.py ###

from .models import CustomHook

def find_and_fire_hook(event_name, instance, **kwargs):
    filters = {
        'event': event_name,
        'is_active': True,
    }

    hooks = CustomHook.objects.filter(**filters)
    for hook in hooks:
        hook.deliver_hook(instance)