How does routers and viewsets configure their urls? - django

I was reading through a long piece of code. And was stuck at how routers and viewsets automatically configure their URLs.
For eg.
the views.py file is:
class UserViewSet(viewsets.ModelViewSet):
authentication_classes = (BasicAuthentication,SessionAuthentication)
permission_classes = (IsAuthenticated,)
serializer_class = UserSerializer
queryset = User.objects.all()
The corresponding urls with router is:
router = DefaultRouter()
router.register(r'users',views.UserViewSet,basename='user')
urlpatterns = router.urls
In the above case, what will be the respective urls for the different actions in viewsets, ie list, create, retrieve, update, partial_update and destroy as mentioned in the djangorestframework documentation on viewsets: http://www.tomchristie.com/rest-framework-2-docs/api-guide/viewsets

When you register the viewset it will generate the following url patterns for above case.
router.register(prefix='users', viewset=views.UserViewSet, basename='user')
It follows the below regex patterns
# Regex for list
r'^{prefix}{trailing_slash}$'
# Regex for detail
r'^{prefix}/{lookup}{trailing_slash}$'
1. List router allows http methods like get to retrieve the resource and post to create the resource.
2. Detail router allows http methods like get to retrieve the data of a a resource,put to update the data of a resource, patch to partial update of resource and delete to delete the resource.
We can also pass a extra keyword argument format while using reverse to generate the dynamic url.
URL patterns for above case
[<URLPattern '^users/$' [name='user-list']>,
<URLPattern '^users\.(?P<format>[a-z0-9]+)/?$' [name='user-list']>,
<URLPattern '^users/(?P<pk>[^/.]+)/$' [name='user-detail']>,
<URLPattern '^users/(?P<pk>[^/.]+)\.(?P<format>[a-z0-9]+)/?$' [name='user-detail']>,
<URLPattern '^$' [name='api-root']>,
<URLPattern '^\.(?P<format>[a-z0-9]+)/?$' [name='api-root']>]
Reference: https://github.com/encode/django-rest-framework/blob/master/rest_framework/routers.py

Related

Django rest_framework DefaultRouter() class vs normal url

I'm using REST in Django, And I couldn't understand what is the main difference between classic URL and instantiating DefaultRouter() for registering URL by ViewSet.
I have a model:
class Article(models.Model):
title = models.CharField()
body = models.TextField()
author = models.ForeignKey()
Serializing model like this:
from blog.models import Article
class ArticleSerializer(serializers.ModelSerializer):
class Meta:
model = Article
fields = ['title', 'body', 'author']
View Class:
from blog.models import Article
from rest_framework import viewsets
from .serializers import ArticleSerializer
class ArticleViewSet(viewsets.ModelViewSet):
serializer_class = ArticleSerializer
queryset = Article.objects.all()
and URLS:
router = DefaultRouter()
router.register(r'articles', ArticleViewSet)
urlpatterns = [
path('', include(router.urls)),
]
Is it possible to use classic URL in URLS.py instead of instantiating the object for a ViewSet like this:
urlpatterns = [
path('api/', 'views.someAPI'),
]
I just know HTTP method in ViewSet translate methods to retrieve, list and etc...
The Question is can we use traditional(Classic) URL style in this situation, Should we ?
Thanks for your help.
Well, in a nutshell as a django developer it is notorious how it is hard to deal with normal urls in django in some cases. Every now and again we get confused with the id type of the detail page that in some case are strings or integers with its regex, and so on.
For example:
urlpatterns = [
url(r'^(?P<content_type_name>[a-zA-z-_]+)$', views.content_type, name = 'content_type'),
]
# or
urlpatterns = [
url(r'^(?P<content_type_name>comics|articles|videos)$', views.content_type, name='content_type'),
]
Not mentioning that in almost every case its needed to have two urls like:
URL pattern: ^users/$ Name: 'user-list'
URL pattern: ^users/{pk}/$ Name: 'user-detail'
THE MAIN DIFFERENCE
However, using DRF routers the example above is done automatically:
# using routers -- myapp/urls.py
router.register(r"store", StoreViewSet, basename="store")
How django will understand it:
^store/$ [name='store-list']
^store\.(?P<format>[a-z0-9]+)/?$ [name='store-list']
^store/(?P<pk>[^/.]+)/$ [name='store-detail']
^store/(?P<pk>[^/.]+)\.(?P<format>[a-z0-9]+)/?$ [name='store-detail']
See how much job and headache you have saved with a line of code only?
To contrast, according to DRF documentation the routers is a type of standard to make it easy to declare urls. A pattern brought from ruby-on-rails.
Here is what the documentation details:
Resource routing allows you to quickly declare all of the common
routes for a given resourceful controller. Instead of declaring
separate routes for your index... a resourceful route declares them in
a single line of code.
— Ruby on Rails Documentation
Django rest framework documentation:
Some Web frameworks such as Rails provide functionality for
automatically determining how the URLs for an application should be
mapped to the logic that deals with handling incoming requests.
REST framework adds support for automatic URL routing to Django, and
provides you with a simple, quick and consistent way of wiring your
view logic to a set of URLs.
For more details follow the django rest framework documentation.

Handle many ViewSets with one URL in the Django rest framework?

What I want is to handle three ViewSet with one URL respect to the provided request.data.
Let's make it more clear by diving into code:
Here is my router.py
# vim: ts=4 sw=4 et
from django.conf.urls import url, include
from rest_framework.routers import DefaultRouter
from . import viewsets
router = DefaultRouter()
router.register(r'endpoint', viewsets.MyViewSet, 'my-viewset')
notification_urls = [
url(r'^', include(router.urls)),
]
Question1:
Is it possible to handle three ViewSet with one URL?
For example, according to the data that has been sent, I want to select dynamically a different ViewSet instead of assigned MyViewSet.
---> /endpoint/ ---- | request.data['platform'] == 1 ----> ViewSet1
| request.data['platform'] == 2 ----> ViewSet2
| request.data['platform'] == 3 ----> ViewSet3
and I know that I can call other ViewSet's methods in a MyViewSet something like this Question but this is really a messy one.
Question2:
Is it possible to dynamically pass extra params respect to the data that has been sent to a ViewSet?
For example, according to the data that has been sent, I want to pass an extra param into MyViewSet.
I know that I can do all this stuff in ViewSet initial method, Like this:
def initial(self, request, *args, **kwargs):
self.set_platform()
super(NotificationViewSet, self).initial(request, *args, **kwargs)
But what I want is to handle this stuff during the MyViewSet instantiation.
NOTE: Maybe I can handle this by Writing a Middleware but if there are other options I would really be appreciated for sharing them with me.

Django-Rest-Framework router register

i'm having a issue when i try to register more than 2 routers using Django-REST-FRAMEWORK. Please take a look on my example:
urls.py
from rest_framework import routers
from collaborativeAPP import views
router = routers.DefaultRouter()
router.register(r'get_vocab', views.VocabViewSet)
router.register(r'get_term', views.TermViewSet)
router.register(r'get_discipline', views.DisciplineViewSet)
urlpatterns = patterns(
...
url(r'^service/', include(router.urls))
)
views.py
class VocabViewSet(viewsets.ModelViewSet):
queryset = Vocab.objects.all()
serializer_class = VocabSerializer
class TermViewSet(viewsets.ModelViewSet):
queryset = Term.objects.all()
serializer_class = TermSerializer
class DisciplineViewSet(viewsets.ModelViewSet):
queryset = Vocab.objects.filter(kwdGroup=4)
serializer_class = DisciplineSerializer
the result in my localhost is the following:
http://localhost:8000/service/
HTTP 200 OK
Content-Type: application/json
Vary: Accept
Allow: GET, HEAD, OPTIONS
{
"get_vocab": "http://127.0.0.1:8000/service/get_discipline/",
"get_term": "http://127.0.0.1:8000/service/get_term/",
"get_discipline": "http://127.0.0.1:8000/service/get_discipline/"
}
As you can see i have registered 3 routers expecting that they will display 3 urls for each methodname(get_vocab, get_term, get_discipline). The final result is get_discipline is occuring two times and get_vocab url is missing.
Notice that for methods that uses different models it works fine, but in case of get_discipline and get_vocab they use the same model which will create this mess. Should i use a viewset for each model? If so, how can a define different methods in a viewset?
It should occur the following result:
HTTP 200 OK
Content-Type: application/json
Vary: Accept
Allow: GET, HEAD, OPTIONS
{
"get_vocab": "http://127.0.0.1:8000/service/get_vocab/",
"get_term": "http://127.0.0.1:8000/service/get_term/",
"get_discipline": "http://127.0.0.1:8000/service/get_discipline/"
}
What am i missing? I supposed that i could register as many routers as i want. It is supposed to have one router per model? Why doesn't seem to work for viewsets that share a same model?
Try explicitly adding a base_name to each registered viewset:
router = routers.DefaultRouter()
router.register(r'vocabs', views.VocabViewSet, 'vocabs')
router.register(r'terms', views.TermViewSet, 'terms')
router.register(r'disciplines', views.DisciplineViewSet, 'disciplines')
As a side note, your should probably exclude get_ prefix in your urls since that is not RESTful. Each URL should specify a resource, not an action on the resource. Thats what HTTP verbs are used for:
GET http://127.0.0.1:8000/service/vocabs/
# or this to create resource
POST http://127.0.0.1:8000/service/vocabs/
...
Here some more information about router:
router = routers.SimpleRouter()
router.register(r'users', UserViewSet)
router.register(r'accounts', AccountViewSet)
urlpatterns = router.urls
Here exist two mandatory arguments for register() method:
prefix : The URL prefix to use for this set of routes.
viewset : The viewset class.
And what abut base_name?
The base to use for the URL names that are created. if you don't set the base_name, it will be automatically generated according to the model or queryset attribute on the viewset.
Here is the URL patterns generated by example above:
URL pattern: ^users/$ Name: 'user-list'
URL pattern: ^users/{pk}/$ Name: 'user-detail'
URL pattern: ^accounts/$ Name: 'account-list'
URL pattern: ^accounts/{pk}/$ Name: 'account-detail'
Now if you want create custome route you should write methods on the viewset decorated with #link or #action like this:
#action(permission_classes=[IsAdminOrIsSelf])
def set_password(self, request, pk=None):
...
The following URL generated:
URL pattern: ^users/{pk}/set_password/$ Name: 'user-set-password'
You used the DefaultRouter and this router is similar to SimpleRouter, but additionally includes a default API root view, that returns a response containing hyperlinks to all the list views. It also generates routes for optional .json style format suffixes.
See this picture of detail table
In previous answer you got the right answer .. me just have given you some more information about router
I am not sure if this is an answer or comment (or a question).
In my case I have two endpoints to a single model and #miki725 answer was not help for me. I was forced to use separated views and separated serializers.
In urls.py I have the 3rd parameter (like #miki725 suggests)
router.register(r'doc_v1', views.DocV1ViewSet, basename='doc_v1')
router.register(r'doc_v2', views.DocV2ViewSet, basename='doc_v2')
But this is not enough. I must use a separated serializers and connect them to the proper detail view via explicitly defined url field:
url = serializers.HyperlinkedIdentityField(view_name='doc_v1-detail')
This is a pain, because (sometimes) both views differ in really minor details like access permissions are. And I have to make almost identical duplicates of view and serializer.
Not good behavior but I have no other solution for now.

JWT authentication doesn't work for custom controller in Django

I am using the Django Rest Framework in my Python app, and am using JSON Web Token Authentication (DRF JWT) for the api authentication.
My problem comes when I am building a custom controller. I pointed a specific URL to a function in my calculations.py file that I created. Following are how they look.
urls.py
from django.conf.urls import patterns, include, url
from django.contrib import admin
from rest_framework import routers
from app.serializers import xxxViewSet, yyyViewSet
from app.calculations import getReturns
router = routers.DefaultRouter()
router.register(r"xxx", xxxViewSet)
router.register(r"yyy", yyyViewSet)
urlpatterns = patterns('',
url(r'^admin/', include(admin.site.urls)),
url(r'^api/auth/token/$', 'rest_framework_jwt.views.obtain_jwt_token'),
url(r'^api/auth/', include('rest_framework.urls', namespace='rest_framework')),
url(r'^api-token-verify/', 'rest_framework_jwt.views.verify_jwt_token'),
url(r'^api/', include(router.urls)),
**url(r'^getReturns/', getReturns),**
)
calculations.py
from django.http import HttpResponse
from .models import xxx, yyy, zzz, aaa
def getReturns(request):
data = request.GET('data')
**running calculations here on data and giving out response**
return HttpResponse(response)
serializers.py
from rest_framework.authentication import SessionAuthentication, BasicAuthentication
from rest_framework import routers, serializers, viewsets, permissions
from rest_framework_jwt.authentication import JSONWebTokenAuthentication
from .models import xxx, yyy, zzz, aaa
class xxxSerializer(serializers.HyperlinkedModelSerializer):
class Meta:
model = xxx
fields = ('id', 'name')
class xxxViewSet(viewsets.ModelViewSet):
authentication_classes = [SessionAuthentication, BasicAuthentication, JSONWebTokenAuthentication]
permission_classes = [permissions.IsAuthenticated, permissions.IsAdminUser]
queryset = xxx.objects.all()
serializer_class = xxxSerializer
The above serializers.py file contains serializer classes for all my models, and also viewsets for the same. I haven't yet transferred the viewsets into views.py, so that file is empty for now.
Anyway, my calculations.pyis separate from these files, and the function defined in this file is directly being called by the '/getReturns/' URL without going through a view. How do I incorporate the functions defined in my calculations file into a viewset so that my authorization classes are called before the function gets executed?
I started doing this in comments and it was too long. Generally, you haven't really provided enough code to assist properly, but here's my crack anyway. It's not obvious which version/implementation of Django JWT you're using (there are a few), how you're authorising your views, or whether your calculations.py file is a view or something else. (If it's something else, I'd authorise in the view, and call it from there.)
Why are you unable to send a POST? Generally, Once you have the token in your front end, you can use from rest_framework.decorators import authentication_classes and #authentication_classes([JSONWebTokenAuthentication,]) wrapper on any function that needs authorisation.
That looks like this:
#authentication_classes([JSONWebTokenAuthentication,])
def function_here(arguments):
#function does stuff
How are you passing/trying to send the web token back to the application?
Presumably in CURL your initial auth to get a token looks something like:
curl -X POST -d "username=admin&password=abc123
after that you get (if you're using rest_framework_jwt) the token back:
{JWTAuthorization: YourTokenHere}.
After that, to return it to DRF protected pages (assuming they're wrapped, as above, or have a similar protection) - you haven't outlined how you're authorisation - then from the docs you do:
curl -H "Authorization: JWT <your_token>" http://localhost:8000/protected-url/
If you're generating the call in Angular or similar, then it's the same - you need to pass it in the headers.
Edit: I'd also note you've drastically increased the amount of code here since my original answer. Fundamentally though, you need to check the auth classes you're declaring; the easiest way is as specified above.

django-rest defaultRouter doesn't add #action

I am reading http://www.django-rest-framework.org/api-guide/routers#usage and can't understand what a base_name is. Also i try to add a custom action and the router won't pick it up
I have this views.py
#authentication_classes((SessionAuthentication, TokenAuthentication))
#permission_classes((IsAuthenticated,))
class utente(CreateModelMixin, RetrieveAPIView, GenericViewSet, ViewSet):
model = MyUser
serializer_class = MyUserSerializer
def retrieve(self, request, *args, **kwargs):
self.object = MyUser.objects.get(
pk = request.user.pk
)
serializer = MyUserSerializerGET(self.object)
return Response(serializer.data)
#action(permission_classes=[IsAuthenticated])#POST action
def customaction(self, request):
return Response( None )
pass
and this urls.py
admin.autodiscover()
router_v1 = routers.DefaultRouter(trailing_slash=True)
router_v1.register(r'register', my_register, 'wtf' )
router_v1.register(r'utente', utente, 'wtf2' )
#router_v1.register(r'utente/customaction', utente.as_view({'post' : 'customaction'}) )
api_urls_v1 = router_v1.urls
api_urls = patterns('',
url(r'^v1/', include(api_urls_v1)),
)
urlpatterns = patterns('',
# Examples:
# url(r'^$', 'wecup.views.home', name='home'),
# url(r'^blog/', include('blog.urls')),
url(r'^admin/', include(admin.site.urls)),
url(r'^login/', 'rest_framework.authtoken.views.obtain_auth_token'),
url(r'^logout/', my_logout ),
url(r'^api/', include(api_urls)),
)
when i open http://127.0.0.1:8000/api/v1/
HTTP 200 OK Content-Type: application/json Vary: Accept Allow: GET, HEAD, OPTIONS
{
"register": "http://127.0.0.1:8000/api/v1/register/",
"utente": "http://127.0.0.1:8000/api/v1/utente/"
where is customaction?
}
You've got two different questions here, so I'll address them each separately.
Base Name
First, a base_name is simply the name the ViewSet will use when generating your named urls. By default, this will simply be your model or perhaps your queryset, though you may need to set it automatically if you've played with your ViewSet's get_queryset method.
If you don't implement your own url names, then the base_name will be used to implement them for you. For example, given that your Model is MyUser, your named urls would be something like 'myuser-list' or 'myuser-detail'.
Documentation, if interested, is here.
#action and custom methods
You're using a DefaultRouter, which allows you to access the API root view at http://127.0.0.1:8000/api/v1/, as you've shown. This root view only shows list views. Using #action creates a detail view. In your case, your customaction view can be found at ^utente/{pk}/customaction/$. It will not show up in the API root because it is not a list view.
General information on #action and custom methods can be found here.
Also, if for some reason you do want to make customaction a list-level view, you'll need to make some modifications. You could either string up a custom route yourself, without using the #action decorator (which is specifically for detail views). An example of that can be found here.
Your other option is to use the new-ish drf-extensions package. A discussion of using the package to implement collection level controllers in ViewSets can be found here.