Django REST API

17. Django REST API#

A RESTful API is an architectural style for an application programming interface that uses HTTP requests to access and use data.
That data can be used to GET , PUT , POST and DELETE data types, which refers to reading, updating, creating and deleting operations related to resources.
Django Rest API Documentation
Video Tutorial

17.1. Basic Construction#

17.1.1. Setting Up Your Django REST Framework (DRF)#

First, install Django REST Framework if you haven’t already:
```
pip install djangorestframework
```

Add rest_framework to your INSTALLED_APPS in django_project/settings.py:

INSTALLED_APPS = [
    ...
    'rest_framework',
    ...
]

17.1.2. Serializers#

Serializers define how the model instances are converted to JSON.

Create a new file serializers.py in your app directory, in our case, under blog folder

# blog/serializers.py

from .models import Post,Comment
from rest_framework import serializers

class PostSerializer(serializers.ModelSerializer):
    class Meta:
        model = Post
        fields = ["id","title","author","content","date_posted"]
        
class PostUpdateSerializer(serializers.ModelSerializer):
    class Meta:
        model = Post
        fields = ["id","title","author","content","date_posted"]
        read_only_fields  = ["id","author"]
        
        
class CommentSerializer(serializers.ModelSerializer):
    class Meta:
        model = Comment
        fields = ["id","post","author","content","date_posted"]
        
class CommentUpdateSerializer(serializers.ModelSerializer):
    class Meta:
        model = Comment
        fields = ["id","post","author","content","date_posted"]
        read_only_fields  = ["id","post","author"]

17.1.3. Create views for Post (Generic Views)#

Use Django REST Framework’s generic views for Post to handle common actions like create, retrieve, update, and delete.
queryset: This attribute defines the set of data that the view will operate on.
serializer_class: This attribute specifies the serializer class that will be used to convert the queryset into JSON format.

    # blog/views.py
    ...
    from rest_framework import generics
    from .models import Post
    from .serializers import PostSerializer

    ...
    class PostListCreateAPIView(generics.ListCreateAPIView):
        queryset = []
        serializer_class = PostSerializer
        
    class PostRetrieveDestroyAPIView(generics.RetrieveDestroyAPIView):
        queryset = Post.objects.all()
        lookup_field = 'pk'
        serializer_class = PostSerializer
        
    class PostUpdateAPIView(generics.UpdateAPIView):
        queryset = Post.objects.all()
        lookup_field = 'pk'
        serializer_class = PostUpdateSerializer

17.1.4. Views for Comment (Customized APIView)#

Add the following code to blog/views.py to handle Comment retrieval with APIView.

class CommentAPIView(views.APIView):
    def get(self,request,format = None):
        content = request.query_params.get("content", "")
        date_posted = request.query_params.get("date_posted", "")
        date_posted_after = request.query_params.get("date_posted_after", "")
        date_posted_before = request.query_params.get("date_posted_before", "")
        
        comments = Comment.objects.all()
        
        if content:
            comments = comments.filter(content__icontains=content)
        
        if date_posted:
            comments = comments.filter(date_posted__date=date_posted)
        
        if date_posted_after:
            comments = comments.filter(date_posted__date__gt=date_posted_after)
        
        if date_posted_before:
            comments = comments.filter(date_posted__date__lt=date_posted_before)
            
        comments = comments.order_by('date_posted')[:5]
            
        serializer = CommentSerializer(comments,many = True)
        return response.Response(serializer.data,status=status.HTTP_200_OK)
        

    def post(self, request, format=None):
        serializer = CommentSerializer(data=request.data)
        if serializer.is_valid():
            serializer.save()
            return response.Response(serializer.data, status=status.HTTP_201_CREATED)
        return response.Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)

17.1.5. URL Configuration#

Set up the URL Pattern

urlpatterns = [
    ...
    path('api/post/create', PostListCreateAPIView.as_view(), name='api-post-create'),
    path('api/post/<int:pk>', PostRetrieveDestroyAPIView.as_view(), name='api-post-qd'),
    path('api/post/<int:pk>/update/', PostUpdateAPIView.as_view(), name='api-post-update'),
    path('api/comment/', CommentAPIView.as_view(), name='api-comment')
]

Test API functionality

curl -X POST http://localhost:8000/api/post/create
{"title":["This field is required."],"author":["This field is required."],"content":["This field is required."]}

curl -X GET http://localhost:8000/api/post/1
{"id":1,"title":"First Post","author":2,"content":"This is the content of the first post1","date_posted":"2024-07-01T13:40:17.920961Z"}

curl -X GET http://localhost:8000/api/comment/?content=insights
[{"id":13,"post":9,"author":3,"content":"Great insights, thank you!","date_posted":"2024-07-01T10:40:00Z"},{"id":36,"post":4,"author":3,"content":"Thanks for the insights!","date_posted":"2024-07-01T12:40:00Z"}]

17.2. Advanced Querying and Filtering#

For more advanced querying, such as searching with wildcards, consider using Django Filters or adding custom query parameters.

17.2.1. Setting Up Your Django REST Filter Framework#

First, install the required Framework if you haven’t already:
```
pip install django-filter
```

Add django-filter to your INSTALLED_APPS in django_project/settings.py:

INSTALLED_APPS = [
    ...
    'django-filter',
    ...
]

17.2.2. Set another Post List View for content query#

filter_backends: This attribute lists the filter backends that will be used to apply filtering, searching, and ordering to the queryset.
- DjangoFilterBackend: Provides filtering based on specified fields. It is part of the django-filter package.
- filters.SearchFilter: Allows searching across specified fields using a query parameter.
- filters.OrderingFilter: Enables ordering of the results based on specified fields.
filterset_fields: This attribute defines the fields that can be used for filtering the queryset.

ordering_fields: This attribute defines the fields that can be used for ordering the results.

class PostListAPIView(generics.ListAPIView):
    queryset = Post.objects.all()
    serializer_class = PostSerializer
    filter_backends = [DjangoFilterBackend, filters.SearchFilter, filters.OrderingFilter]
    filterset_fields = ['author']
    search_fields = ['title', 'content']
    ordering_fields = ['date_posted']

17.2.3. URL Configuration#