Drf: Getting related posts by ManyToMany category and a tags field

Question

I'm trying to get all related posts by getting the id of the current post and filtering through the DB to find posts that are either in a similar category or have similar tags.

this is the model for the posts:

class Post(models.Model):
    ....
    author = models.ForeignKey(
        "users.User", on_delete=models.CASCADE, related_name='blog_posts')
    tags = TaggableManager()
    categories = models.ManyToManyField(
        'Category')
    ....
    status = models.IntegerField(choices=blog_STATUS, default=0)

    def __str__(self):
        return self.title

this is the views.py file:

class RelatedPostsListAPIView(generics.ListAPIView):
    serializer_class = PostsSerializer
    queryset = BlogPost.objects.filter(
        status=1)[:5]
    model = BlogPost

def get_context_data(self, **kwargs):
    context = super(RelatedPostsListAPIView,
                    self).get_context_data(**kwargs)
    pk = self.kwargs['pk']
    main_post = BlogPost.objects.get(pk=pk)

    related_posts = main_post.filter(
        Q(categories__in=main_post.categories.all()) |
        Q(tags__in=main_post.tags.all())).exclude(pk=pk)[:5]

    context['related_posts'] = related_posts
    return context

this is the serializer

    class CategoriesSerializer(serializers.ModelSerializer):

    class Meta:
        model = Category
        fields = ['id', 'title', 'slug']


class PostsSerializer(TaggitSerializer, serializers.ModelSerializer):
    categories = CategoriesSerializer(many=True)
    author = UserSerializer()
    tags = TagListSerializerField()
    cover = serializers.SerializerMethodField('get_image_url')

    class Meta:
        model = BlogPost
        fields = [
            "id",
            "title",
            "slug",
            "author",
            "description",
            "content",
            "tags",
            "categories",
            "keywords",
            "cover",
            "created_on",
            "updated_on",
            "status",
        ]

    def get_image_url(self, obj):
        request = self.context.get("request")
        return request.build_absolute_uri(obj.cover.url)

url pattern:

urlpatterns = [
    path('all/', PostsListAPIView.as_view(), name="all_posts"),
    path('recent/', RecentPostsListAPIView.as_view(), name="recent_posts"),
    path('related/<int:pk>/', RelatedPostsListAPIView.as_view(), name="related_posts")
]

with this code I get a RelatedPostsListAPIView.get() got multiple values for argument 'pk' error, I don't think I am actually getting the object with the id, any help would be much appreciated.

Answer 1

You also have to capture request in get(), so change:

class RelatedPostsListAPIView(generics.ListAPIView):
    def get(self, pk):
        # ...

to:

class RelatedPostsListAPIView(generics.ListAPIView):
    def get(self, request, pk):
        #         ^^^ Add this