Django REST framework basic components

1. Serialization components

Simple use

The first thing to develop our Web API is to provide a way for our Web API to serialize and deserialize code snippet instances into representations such as json.We can do this by declaring serializers that are very similar to Django forms.

models section:

from django.db import models

# Create your models here.


class Book(models.Model):
    title=models.CharField(max_length=32)
    price=models.IntegerField()
    pub_date=models.DateField()
    publish=models.ForeignKey("Publish")
    authors=models.ManyToManyField("Author")
    def __str__(self):
        return self.title

class Publish(models.Model):
    name=models.CharField(max_length=32)
    email=models.EmailField()
    def __str__(self):
        return self.name

class Author(models.Model):
    name=models.CharField(max_length=32)
    age=models.IntegerField()
    def __str__(self):
        return self.name

views section:

from rest_framework.views import APIView
from rest_framework.response import Response
from .models import *
from django.shortcuts import HttpResponse
from django.core import serializers


from rest_framework import serializers

class BookSerializers(serializers.Serializer):
    title=serializers.CharField(max_length=32)
    price=serializers.IntegerField()
    pub_date=serializers.DateField()
    publish=serializers.CharField(source="publish.name")
    #authors=serializers.CharField(source="authors.all")
    authors=serializers.SerializerMethodField()
    def get_authors(self,obj):
        temp=[]
        for author in obj.authors.all():
            temp.append(author.name)
        return temp


class BookViewSet(APIView):

    def get(self,request,*args,**kwargs):
        book_list=Book.objects.all()
        # Serialization method 1:
        # from django.forms.models import model_to_dict
        # import json
        # data=[]
        # for obj in book_list:
        #     data.append(model_to_dict(obj))
        # print(data)
        # return HttpResponse("ok")

        # Serialization mode 2:
        # data=serializers.serialize("json",book_list)
        # return HttpResponse(data)

        # Serialization mode 3:
        bs=BookSerializers(book_list,many=True)
        return Response(bs.data)

ModelSerializer

class BookSerializers(serializers.ModelSerializer):
      class Meta:
          model=Book
          fields="__all__"
          depth=1

Submit post request

  def post(self,request,*args,**kwargs):
       
        bs=BookSerializers(data=request.data,many=False)
        if bs.is_valid():
            # print(bs.validated_data)
            bs.save()
            return Response(bs.data)
        else:
            return HttpResponse(bs.errors)

Override create method in save

class BookSerializers(serializers.ModelSerializer):

      class Meta:
          model=Book
          fields="__all__"
          # exclude = ['authors',]
          # depth=1

      def create(self, validated_data):
        
          authors = validated_data.pop('authors')
          obj = Book.objects.create(**validated_data)
          obj.authors.add(*authors)
          return obj

get and put requests for single data

class BookDetailViewSet(APIView):

    def get(self,request,pk):
        book_obj=Book.objects.filter(pk=pk).first()
        bs=BookSerializers(book_obj)
        return Response(bs.data)

    def put(self,request,pk):
        book_obj=Book.objects.filter(pk=pk).first()
        bs=BookSerializers(book_obj,data=request.data)
        if bs.is_valid():
            bs.save()
            return Response(bs.data)
        else:
            return HttpResponse(bs.errors)

Hyperlink API:Hyperlink

class BookSerializers(serializers.ModelSerializer):
      publish= serializers.HyperlinkedIdentityField(
                     view_name='publish_detail',
                     lookup_field="publish_id",
                     lookup_url_kwarg="pk")
      class Meta:
          model=Book
          fields="__all__"
          #depth=1

The urls section:

`urlpatterns ``=` `[``    ``url(r``'^books/$'``, views.BookViewSet.as_view(),name``=``"book_list"``),``    ``url(r``'^books/(?P<pk>\d+)$'``, views.BookDetailViewSet.as_view(),name``=``"book_detail"``),``    ``url(r``'^publishers/$'``, views.PublishViewSet.as_view(),name``=``"publish_list"``),``    ``url(r``'^publishers/(?P<pk>\d+)$'``, views.PublishDetailViewSet.as_view(),name``=``"publish_detail"``),``]`

2. View Trilogy of View Components

Use mixins

View section of the previous section:

from rest_framework.views import APIView
from rest_framework.response import Response
from .models import *
from django.shortcuts import HttpResponse
from django.core import serializers
from rest_framework import serializers


class BookSerializers(serializers.ModelSerializer):
      class Meta:
          model=Book
          fields="__all__"
          #depth=1


class PublshSerializers(serializers.ModelSerializer):

      class Meta:
          model=Publish
          fields="__all__"
          depth=1


class BookViewSet(APIView):

    def get(self,request,*args,**kwargs):
        book_list=Book.objects.all()
        bs=BookSerializers(book_list,many=True,context={'request': request})
        return Response(bs.data)


    def post(self,request,*args,**kwargs):
        print(request.data)
        bs=BookSerializers(data=request.data,many=False)
        if bs.is_valid():
            print(bs.validated_data)
            bs.save()
            return Response(bs.data)
        else:
            return HttpResponse(bs.errors)


class BookDetailViewSet(APIView):

    def get(self,request,pk):
        book_obj=Book.objects.filter(pk=pk).first()
        bs=BookSerializers(book_obj,context={'request': request})
        return Response(bs.data)

    def put(self,request,pk):
        book_obj=Book.objects.filter(pk=pk).first()
        bs=BookSerializers(book_obj,data=request.data,context={'request': request})
        if bs.is_valid():
            bs.save()
            return Response(bs.data)
        else:
            return HttpResponse(bs.errors)


class PublishViewSet(APIView):

    def get(self,request,*args,**kwargs):
        publish_list=Publish.objects.all()
        bs=PublshSerializers(publish_list,many=True,context={'request': request})
        return Response(bs.data)


    def post(self,request,*args,**kwargs):

        bs=PublshSerializers(data=request.data,many=False)
        if bs.is_valid():
            # print(bs.validated_data)
            bs.save()
            return Response(bs.data)
        else:
            return HttpResponse(bs.errors)


class PublishDetailViewSet(APIView):

    def get(self,request,pk):

        publish_obj=Publish.objects.filter(pk=pk).first()
        bs=PublshSerializers(publish_obj,context={'request': request})
        return Response(bs.data)

    def put(self,request,pk):
        publish_obj=Publish.objects.filter(pk=pk).first()
        bs=PublshSerializers(publish_obj,data=request.data,context={'request': request})
        if bs.is_valid():
            bs.save()
            return Response(bs.data)
        else:
            return HttpResponse(bs.errors)

mixin class authoring view

from rest_framework import mixins
from rest_framework import generics

class BookViewSet(mixins.ListModelMixin,
                  mixins.CreateModelMixin,
                  generics.GenericAPIView):

    queryset = Book.objects.all()
    serializer_class = BookSerializers

    def get(self, request, *args, **kwargs):
        return self.list(request, *args, **kwargs)

    def post(self, request, *args, **kwargs):
        return self.create(request, *args, **kwargs)



class BookDetailViewSet(mixins.RetrieveModelMixin,
                    mixins.UpdateModelMixin,
                    mixins.DestroyModelMixin,
                    generics.GenericAPIView):
    queryset = Book.objects.all()
    serializer_class = BookSerializers

    def get(self, request, *args, **kwargs):
        return self.retrieve(request, *args, **kwargs)

    def put(self, request, *args, **kwargs):
        return self.update(request, *args, **kwargs)

    def delete(self, request, *args, **kwargs):
        return self.destroy(request, *args, **kwargs)

Use a generic class-based view

By using the mixin class, we override these views with less code, but we can go further.The REST framework provides a set of mixed-in common views that we can use to simplify our views.py module.

from rest_framework import mixins
from rest_framework import generics

class BookViewSet(generics.ListCreateAPIView):

    queryset = Book.objects.all()
    serializer_class = BookSerializers

class BookDetailViewSet(generics.RetrieveUpdateDestroyAPIView):
    queryset = Book.objects.all()
    serializer_class = BookSerializers

class PublishViewSet(generics.ListCreateAPIView):

    queryset = Publish.objects.all()
    serializer_class = PublshSerializers

class PublishDetailViewSet(generics.RetrieveUpdateDestroyAPIView):
    queryset = Publish.objects.all()
    serializer_class = PublshSerializers

viewsets.ModelViewSet

urls.py:

    url(r'^books/$', views.BookViewSet.as_view({"get":"list","post":"create"}),name="book_list"),
    url(r'^books/(?P<pk>\d+)$', views.BookViewSet.as_view({
                'get': 'retrieve',
                'put': 'update',
                'patch': 'partial_update',
                'delete': 'destroy'
            }),name="book_detail"),

views.py:

class BookViewSet(viewsets.ModelViewSet):
    queryset = Book.objects.all()
    serializer_class = BookSerializers

3. Authentication components

Local View Authentication

In app01.service.auth.py:

class Authentication(BaseAuthentication):

    def authenticate(self,request):
        token=request._request.GET.get("token")
        token_obj=UserToken.objects.filter(token=token).first()
        if not token_obj:
            raise exceptions.AuthenticationFailed("Validation failed!")
        return (token_obj.user,token_obj)

In views.py:

def get_random_str(user):
    import hashlib,time
    ctime=str(time.time())

    md5=hashlib.md5(bytes(user,encoding="utf8"))
    md5.update(bytes(ctime,encoding="utf8"))

    return md5.hexdigest()


from app01.service.auth import *

from django.http import JsonResponse
class LoginViewSet(APIView):
    authentication_classes = [Authentication,]
    def post(self,request,*args,**kwargs):
        res={"code":1000,"msg":None}
        try:
            user=request._request.POST.get("user")
            pwd=request._request.POST.get("pwd")
            user_obj=UserInfo.objects.filter(user=user,pwd=pwd).first()
            print(user,pwd,user_obj)
            if not user_obj:
                res["code"]=1001
                res["msg"]="User name or password error"
            else:
                token=get_random_str(user)
                UserToken.objects.update_or_create(user=user_obj,defaults={"token":token})
                res["token"]=token

        except Exception as e:
            res["code"]=1002
            res["msg"]=e

        return JsonResponse(res,json_dumps_params={"ensure_ascii":False})

Global View Authentication Component

The settings.py configuration is as follows:

`REST_FRAMEWORK``=``{``    ``"DEFAULT_AUTHENTICATION_CLASSES"``:[``"app01.service.auth.Authentication"``,]``}`

IV. Permission Components

Local View Permissions

In app01.service.permissions.py:

from rest_framework.permissions import BasePermission
class SVIPPermission(BasePermission):
    message="SVIP Can access!"
    def has_permission(self, request, view):
        if request.user.user_type==3:
            return True
        return False

In views.py:

from app01.service.permissions import *

class BookViewSet(generics.ListCreateAPIView):
    permission_classes = [SVIPPermission,]
    queryset = Book.objects.all()
    serializer_class = BookSerializers

Global View Permissions

The settings.py configuration is as follows:

`REST_FRAMEWORK``=``{``    ``"DEFAULT_AUTHENTICATION_CLASSES"``:[``"app01.service.auth.Authentication"``,],``    ``"DEFAULT_PERMISSION_CLASSES"``:[``"app01.service.permissions.SVIPPermission"``,]``}`

5. throttle components

Local view throttle

In app01.service.throttles.py:

from rest_framework.throttling import BaseThrottle

VISIT_RECORD={}
class VisitThrottle(BaseThrottle):

    def __init__(self):
        self.history=None

    def allow_request(self,request,view):
        remote_addr = request.META.get('REMOTE_ADDR')
        print(remote_addr)
        import time
        ctime=time.time()

        if remote_addr not in VISIT_RECORD:
            VISIT_RECORD[remote_addr]=[ctime,]
            return True

        history=VISIT_RECORD.get(remote_addr)
        self.history=history

        while history and history[-1]<ctime-60:
            history.pop()

        if len(history)<3:
            history.insert(0,ctime)
            return True
        else:
            return False

    def wait(self):
        import time
        ctime=time.time()
        return 60-(ctime-self.history[-1])

In views.py:

from app01.service.throttles import *

class BookViewSet(generics.ListCreateAPIView):
    throttle_classes = [VisitThrottle,]
    queryset = Book.objects.all()
    serializer_class = BookSerializers

Global view throttle

REST_FRAMEWORK={
    "DEFAULT_AUTHENTICATION_CLASSES":["app01.service.auth.Authentication",],
    "DEFAULT_PERMISSION_CLASSES":["app01.service.permissions.SVIPPermission",],
    "DEFAULT_THROTTLE_CLASSES":["app01.service.throttles.VisitThrottle",]
}

Built-in throttle class

In app01.service.throttles.py, change to:

class VisitThrottle(SimpleRateThrottle):

    scope="visit_rate"
    def get_cache_key(self, request, view):

        return self.get_ident(request)

settings.py settings:

REST_FRAMEWORK={
    "DEFAULT_AUTHENTICATION_CLASSES":["app01.service.auth.Authentication",],
    "DEFAULT_PERMISSION_CLASSES":["app01.service.permissions.SVIPPermission",],
    "DEFAULT_THROTTLE_CLASSES":["app01.service.throttles.VisitThrottle",],
    "DEFAULT_THROTTLE_RATES":{
        "visit_rate":"5/m",
    }
}

6. Parser

request class

Source code resolution for django's request class and rest-framework's request class

Local View

from rest_framework.parsers import JSONParser,FormParser
class PublishViewSet(generics.ListCreateAPIView):
    parser_classes = [FormParser,JSONParser]
    queryset = Publish.objects.all()
    serializer_class = PublshSerializers
    def post(self, request, *args, **kwargs):
        print("request.data",request.data)
        return self.create(request, *args, **kwargs)

Global View

REST_FRAMEWORK={
    "DEFAULT_AUTHENTICATION_CLASSES":["app01.service.auth.Authentication",],
    "DEFAULT_PERMISSION_CLASSES":["app01.service.permissions.SVIPPermission",],
    "DEFAULT_THROTTLE_CLASSES":["app01.service.throttles.VisitThrottle",],
    "DEFAULT_THROTTLE_RATES":{
        "visit_rate":"5/m",
    },
    "DEFAULT_PARSER_CLASSES":['rest_framework.parsers.FormParser',]
}

7. Paging

Simple Paging

from rest_framework.pagination import PageNumberPagination,LimitOffsetPagination

class PNPagination(PageNumberPagination):
        page_size = 1
        page_query_param = 'page'
        page_size_query_param = "size"
        max_page_size = 5

class BookViewSet(viewsets.ModelViewSet):

    queryset = Book.objects.all()
    serializer_class = BookSerializers
    def list(self,request,*args,**kwargs):

        book_list=Book.objects.all()
        pp=LimitOffsetPagination()
        pager_books=pp.paginate_queryset(queryset=book_list,request=request,view=self)
        print(pager_books)
        bs=BookSerializers(pager_books,many=True)

        #return Response(bs.data)
        return pp.get_paginated_response(bs.data)

Offset Paging

from rest_framework.pagination import LimitOffsetPagination

Keywords: Python Django JSON REST encoding

Added by ztealmax on Thu, 12 Sep 2019 19:40:26 +0300

Programming VIP

Django REST framework basic components

1. Serialization components

Simple use

ModelSerializer

Submit post request

Override create method in save

get and put requests for single data

Hyperlink API:Hyperlink

2. View Trilogy of View Components

Use mixins

mixin class authoring view

Use a generic class-based view

viewsets.ModelViewSet

3. Authentication components

Local View Authentication

Global View Authentication Component

IV. Permission Components

Local View Permissions

Global View Permissions

5. throttle components

Local view throttle

Global view throttle

Built-in throttle class

6. Parser

request class

Local View

Global View

7. Paging

Simple Paging

Offset Paging

Popular Keywords