Tastypie is a django app that lets you quickly expose RESTful web services from your existing Django models

1. Build and Customize RESTful Web
Services with Django-Tastypie
@gauravtoshniwal
Gaurav Toshniwal
Co-founder, WireddIn Interactive Pvt. Ltd.
(Mobile and Web App development)

2. Outline of the Talk
 Why REST?
 Why Tastypie?
 Why not Tastypie?
 Basic API setup from a model
 DEMO
 Related Models/ Exclude/ Include/ Serializers
 Ordering/Filtering/Bulk Operations
 Authentication
 Authorization
 Customization (Complex Filters/Hydrate/Dehydrate)
 O & A

3. About REST
 Client-Server
 Stateless
 Cacheable
 Layered System
 Uniform Interface

4. About REST: Vocabulary
 GET
 POST
 PUT
 PATCH
 DELETE

5. About REST: RESTful Web APIs
 A RESTful web API (also called a RESTful web service) is a
web API implemented using HTTP and REST principles. It is
a collection of resources, with four defined aspects:
 the base URI for the web API, such as
http://example.com/resources/
 the Internet media type of the data supported by the web
API. This is often JSON but can be any other valid Internet
media type provided that it is a valid hypertext standard.
 the set of operations supported by the web API using HTTP
methods (e.g., GET, PUT, POST, or DELETE).
 The API must be hypertext driven.

6. What Is Tastypie?
 "Tastypie is an webservice API framework for Django. It
provides a convenient, yet powerful and highly
customizable, abstraction for creating REST-style
interfaces.”
 Ranked high in Django-Packages ranking algorithm

7. Why not Tastypie?

8. Why Tastypie?
 Makes Sense – quick and feature-rich
 Well Tested
 Good features and support, fits well into existing ORM
thinking
 Totally Extensible
 Serialization methods
 Authentication and authorization in-built
 Other features: Throttling

9. Basic API setup: Define model
from django.db import models
class Todo(models.Model):
todo = models.CharField(max_length=100, blank=False)
done = models.BooleanField("Done",blank=True,
default=False)
def __unicode__(self):
return "%s" % self.todo

10. Basic API setup: Define Resources
from tastypie.resources import ModelResource
from tastypie import fields
from tastypie.serializers import Serializer
from tastypie.constants import ALL, ALL_WITH_RELATIONS
from todo.models import Todo
class TodoResource(ModelResource):
class Meta:
queryset = Todo.objects.all()
resource_name = 'todo’

11. Basic API setup: Hook up URLs
from django.conf.urls import patterns, include, url
from django.contrib import admin
admin.autodiscover()
from tastypie.api import Api
api = Api(api_name='v1')
from todo.api.resources import TodoResource
api.register(TodoResource())
urlpatterns = patterns('',
url(r'^admin/', include(admin.site.urls)),
(r'^api/', include(api.urls)),
)

12. Basic API setup: DEMO
 Schema
 POST demo (create data)
 View data in Admin
 GET demo (retrieve data)
 without format=json
 with format=json
 with format=xml, yaml
 /set/1;5/?format=json
 DELETE demo

13. Related Models/ Exclude/ Include/
Serializers
class UserTodo(models.Model):
todo = models.CharField(max_length=100, blank=False)
done = models.BooleanField("Done",blank=True,
default=False)
due = models.DateField(blank=True)
created = models.DateField(auto_now_add=True)
user = models.ForeignKey(User)
def __unicode__(self):
return "%s" % self.todo

14. Related Models/ Exclude/ Include/
Serializers
class UserResource(ModelResource):
class Meta:
queryset = User.objects.all()
resource_name = 'user'
excludes = ['email',
'password',
'is_superuser']
serializer = Serializer(formats=['json'])
class UserTodoResource(ModelResource):
user = fields.ForeignKey(UserResource, 'user')
class Meta:
queryset = UserTodo.objects.all()
resource_name = 'user_todo'
fields = ['todo', 'user','due']
serializer = Serializer(formats=['json'])
authorization = Authorization()
Exclude fields from API output
Include only these fields
Built-in Authorize everyone for
everything option
Foreign key

15. To be added:
 Request-response cycle
 Filtering
 Advanced Data preparation (customized logic):
 The Dehydrate Cycle (customize output)
 The Hydrate Cycle (customize input)
 Authentication
 Authorization

16. Request Response Cycle
Request
• Resource.wrap_view(‘dispatch_list’)
Dispatch_list
dispatch
• Checks
• Allowed methods
• If the class has a method that can handle the request (get_list)
• Is_authenticated
• Is_authorized
• Throttle_check
Get_list
• Obj_get_list
• Build_filters
• Get_objects_list (gets the queryset)
• apply_authorization_limits (to limit the set the user can work with)
• sorting
• pagination
• Full_dehydrate raw data to objects)
Create_response
• Serialization
• Return httpResponse