What it's really like building RESTful Web APIs with Django

Experiences building RESTful web services using Django REST Framework, from EuroPython 2015

Transcript

1. 1 Paul Hallett 23.07.2015 What it’s really like building RESTful APIs with Django.
2. 2 Paul Hallett Writing software for ~7 years Working at Lyst @phalt_ Me ! API Fanatic
3. 3 http://pokeapi.co
4. 4 https://swapi.co
8. 8 curl -s -X POST -d ' { "jsonrpc": "2.0", "method": "product.get", "params": { "username":"USERNAME", "password":"PASSWORD", "product":"PRODUCT_SLUG" }, "id": 1}' https://api.lyst.com/rpc/v1/
9. 9 curl -s -X POST -d ' { "jsonrpc": "2.0", "method": "product.get", "params": { "username":"USERNAME", "password":"PASSWORD", "product":"PRODUCT_SLUG" }, "id": 1}' https://api.lyst.com/rpc/v1/
10. 10 curl -s -X POST -d ' { "jsonrpc": "2.0", "method": "user.register", "params": { "email":"dummy@lyst.com", "username":"dummy", "password":"p123456", "gender":"M" }, "id": 1}' https://api.lyst.com/rpc/v1/
11. 11 curl -s -X POST -d ' { "jsonrpc": "2.0", "method": "user.register", "params": { "email":"dummy@lyst.com", "username":"dummy", "password":"p123456", "gender":"M" }, "id": 1}' https://api.lyst.com/rpc/v1/
12. 12 curl -s -X POST -d ' { "jsonrpc": "2.0", "method": "product.get", "params": { "username":"USERNAME", "password":"PASSWORD", "product":"PRODUCT_SLUG" }, "id": 1}' https://api.lyst.com/rpc/v1/
13. 13 RPC for HTTP is bad 13
14. 14 Don’t use it 14
15. 15 Rebuilding with Django Rest Framework 15
16. 16 Why Django Rest Framework? 16
17. 17 Batteries Included Web Framework
18. 18 Batteries Included API Framework Batteries Included Web Framework
19. 19 Batteries Included Web Framework Batteries Included API Framework
20. 20 What we learned 20
21. 21 21 A chance to rebuild
22. 22 22 Design first. Code second.
23. 23 23 Resources
24. 24 24 Resources != Models
25. 25 Creating resources - Cart - state - country - cart_type - user - shipping_title - shipping_firstname - shipping_lastname - shipping_email - shipping_phone - shipping_address_1 - shipping_address_2 - billing_title - billing_firstname - billing_lastname - billing_email - billing_phone - billing_address_1 - billing_address_2
26. 26 26 Serializers
27. 27 class CartSerializer(serializers.ModelSerializer): def get_item_count(self, instance): return instance.items.count() item_count = serializers.SerializerMethodField() class Meta: model = Cart fields = ( 'state', 'country', 'cart_type', 'user_type', 'date_added', 'date_updated', 'item_count', 'shipping_price', 'currency', 'resource_url’, )
28. 28 - Cart - state - country - cart_type - user - shipping_title - shipping_firstname - shipping_lastname - shipping_email - shipping_phone - shipping_address_1 - shipping_address_2 - billing_title - billing_firstname - billing_lastname - billing_email - billing_phone - billing_address_1 - billing_address_2 - Cart - state - country - cart_type - user - item_count - shipping - shipping_title - shipping_firstname - shipping_lastname - shipping_email - shipping_phone - shipping_address_1 - shipping_address_2 - billing - billing_title - billing_firstname - billing_lastname - billing_email - billing_phone - billing_address_1 - billing_address_2 Creating resources
29. 29 - Cart - state - country - cart_type - user - shipping_title - shipping_firstname - shipping_lastname - shipping_email - shipping_phone - shipping_address_1 - shipping_address_2 - billing_title - billing_firstname - billing_lastname - billing_email - billing_phone - billing_address_1 - billing_address_2 - Cart - state - country - type - user - item_count - shipping - title - firstname - lastname - email - phone - address_1 - address_2 - billing - title - firstname - lastname - email - phone - address_1 - address_2 Creating resources
30. 30 30 Routers
31. 31 31 Write your own URLconf
32. 32 32 Permissions
33. 33 'DEFAULT_PERMISSION_CLASSES': ( 'rest_framework.permissions.AllowAny', )
34. 34 'DEFAULT_PERMISSION_CLASSES': ( 'rest_framework.permissions.AdminOnly', )
35. 35 class CheckoutAPIView(BaseAPIView): """ Common methods for all Checkout resources. """ permission_classes = (IsAuthenticated,)
36. 36 36 Authentication
37. 37 pip install django-oauth-toolkit
38. 38 INSTALLED_APPS = ( . . . 'ouath2_toolkit', . . . )
39. 39 'DEFAULT_AUTHENTICATION_CLASSES': ( 'oauth2_provide.ext.rest_framework.OAuth2Authentication', )
40. 40 request.user
41. 41 41
42. 42 42 HTTP only provides so much
43. 43 43 HTTP CHECKOUT?
44. 44 44 HTTP POST api.lyst.com/cart/checkout/
45. 45 45 Asynchronous?
46. 46 46 HTTP POST api.lyst.com/cart/checkout/ { callback_url : ‘mywebsite.com/checkout_complete/' }
47. 47 47 HTTP 202 ACCEPTED { . . . }
48. 48 48 Documentation
49. Django REST Framework has so many cool things, use them. Design before you build. Use this opportunity to redesign your data model and services. Go off the beaten track only when you have to. Document well. Don’t use RPC 49 Wrap up
50. thank you Paul Hallett @phalt_