Django-Rest-Framework-CRUD-function-views.py

#VIEWS.PY
@api_view(['GET'])
@permission_classes([AllowAny])
def topics_view(request):
    topics = Topic.objects.all().prefetch_related('author')
    serializer = TopicSerializer(topics, many=True)
    return Response(serializer.data, status=status.HTTP_200_OK)


@api_view(['GET'])
@permission_classes([AllowAny])
def topic_detail_view(request, id):
    try:
        topic = Topic.objects.get(id=id)
    except Topic.DoesNotExist:
        message = {'error': 'Topic not found'}
        return Response(message, status=status.HTTP_400_BAD_REQUEST)
    serializer = TopicSerializer(topic)
    return Response(serializer.data, status=status.HTTP_200_OK)


@api_view(['POST'])
@permission_classes([IsAuthenticated])
@authentication_classes([TokenAuthentication])
@parser_classes([MultiPartParser, FormParser])
def create_topic_view(request, format=None):
    serializer = TopicSerializer(data=request.data)

    if serializer.is_valid():
        new_topic = serializer.save()
        new_topic.image_url = f'{fetch_host(request)}{new_topic.image.url}'
        new_topic.user_created_topic = True
        new_topic.save()

        message = {**serializer.data, 'message':'Successfully created'}
        return Response(message, status=status.HTTP_201_CREATED)
    return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)


@api_view(['PUT'])
@permission_classes([IsAuthenticated])
@authentication_classes([TokenAuthentication])
@parser_classes([MultiPartParser, FormParser])
def update_topic_view(request, id, format=None):
    try:
        topic = Topic.objects.get(id=id, author=request.user)
    except Topic.DoesNotExist:
        message = {'error': 'Topic not found.'}
        return Response(message, status=status.HTTP_404_NOT_FOUND)

    serializer = TopicSerializer(topic, data=request.data)

    if serializer.is_valid():
        serializer.save()
        message = {**serializer.data, 'message':'Successfully created'}
        return Response(message, status=status.HTTP_202_ACCEPTED)
    return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)


@api_view(['POST'])
@permission_classes([IsAuthenticated])
@authentication_classes([TokenAuthentication])
def delete_topic_view(request, id):
    try:
        topic = Topic.objects.get(id=id)
    except Topic.DoesNotExist:
        message = {'error': 'Topic not found.'}
        return Response(message, status=status.HTTP_404_NOT_FOUND)

    topic.delete()

    message = {'message': f'{topic.name} has been deleted successfully.'}
    return Response(message, status=status.HTTP_204_NO_CONTENT)


@api_view(['GET'])
@permission_classes([AllowAny])
def post_list_view(request):
    posts = Post.objects.all().prefetch_related('like', 'topic', 'author')
    serializer = PostSerializer(posts, many=True)
    return Response(serializer.data, status=status.HTTP_200_OK)


@api_view(['GET'])
@permission_classes([AllowAny])
def post_detail_view(request, id):
    try:
        post = Post.objects.prefetch_related('topic', 'author', 'like').get(id=id)
    except Post.DoesNotExist:
        error = {'message':'Post not found.'}
        return Response(error, status=status.HTTP_404_NOT_FOUND)

    serializer = PostSerializer(post)
    author_profile_image_url = post.author.profile.image_url
    usernames = [user.username for user in post.like.all()]

    data = {
        **serializer.data,
        'author_profile_image_url': author_profile_image_url,
        'like':usernames,
    }
    return Response(data, status=status.HTTP_200_OK)


@api_view(['POST'])
@permission_classes([IsAuthenticated])
@authentication_classes([TokenAuthentication])
@parser_classes([MultiPartParser, FormParser])
def create_post_view(request, format=None):
    try:
        topic = Topic.objects.get(name__iexact=request.data.get('topic'))
    except Topic.DoesNotExist:
        message = {'error': 'Topic not found.'}
        return Response(message, status=status.HTTP_404_NOT_FOUND)

    serializer = PostSerializer(data=request.data)
    if serializer.is_valid():
        new_post = serializer.save()
        new_post.author = request.user
        new_post.topic = topic
        new_post.image_url = f'{fetch_host(request)}{new_post.image.url}'
        new_post.save()

        new_post.topic.update_total_post()

        message = {**serializer.data, 'message':'Successfully created'}
        return Response(message, status=status.HTTP_201_CREATED)
    return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)


@api_view(['PUT'])
@permission_classes([IsAuthenticated])
@authentication_classes([TokenAuthentication])
@parser_classes([MultiPartParser, FormParser])
def update_post_view(request, id, format=None):
    user = request.user
    post = Post.objects.filter(id=id, author=user).first()

    if post == None:
        message = {'error': 'Post not found.'}
        return Response(message, status=status.HTTP_404_NOT_FOUND)

    else:
        serializer = PostSerializer(post, data=request.data)
        if serializer.is_valid():
            updated_post = serializer.save()
            if serializer.validated_data.get('image'):
                updated_post.image_url = f'{fetch_host(request)}{updated_post.image.url}'
            updated_post.save()

            message = {**serializer.data, 'message':'Successfully updated'}
            return Response(message, status=status.HTTP_202_ACCEPTED)
        return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)


@api_view(['DELETE'])
@permission_classes([IsAuthenticated])
@authentication_classes([TokenAuthentication])
def delete_post_view(request, id):
    user = request.user
    post = Post.objects.filter(id=id, author=user).first()

    if post == None:
        message = {'error':"Post not found"}
        return Response(message, status=status.HTTP_404_NOT_FOUND)

    else:
        post.delete()
        post.topic.update_total_post()
        message = {'message': f'Post has been deleted successfully.'}
    return Response(message, status=status.HTTP_200_OK)


@api_view(['POST'])
@permission_classes([IsAuthenticated])
@authentication_classes([TokenAuthentication])
def update_post_like_view(request, id):
    user = request.user

    try:
        post = Post.objects.prefetch_related('like').get(id=id)
    except Post.DoesNotExist:
        message = {'error':'Post not found'}
        return Response(message, status=status.HTTP_404_NOT_FOUND)

    if user not in post.like.all():
        post.like.add(user)
        post.save()
        message = {'message': 'Submmision was successfull.'}
        return Response(message, status=status.HTTP_200_OK)
    message = {'error': 'You have already submited.'}
    return Response(message, status=status.HTTP_400_BAD_REQUEST)