Django Rest Framework return True if relation exist

Question

I have two questions. How i can just return true if relation exist? For example I have post model and comment model also, comment have foreginKey to post. Now after post serialization i wanna have something like this

{
id: 2
content: "My first post!"
has-comments: True
}

And my second question is how rename field name in model relation? Again we have post and comment. In comment model i have foregin key to post like

post = models.ForeignKey(Post)

Now when i add new comment i send JSON data with {post: postIdHere}. Is possible to change post to postId only in drf not in django model?

I hope you understand me :) Best Redgards, Sierran.

Brian · Accepted Answer · 2016-09-21 13:37:55Z

1

The closest thing I can come up with is a custom has_comments field (rather than has-comments) with this in the serializer:

from rest_framework import serializers

class YourSerializer(Either Serializer or ModelSerializer...):
    has_comments = serializers.SerializerMethodField()
    @staticmethod
    def get_has_comments(instance):
        # Choose whichever one works for you.
        # You did not specify some model names, so I am just making stuff up.
        return instance.post_set.exists()
        return Comment.objects.filter(post_id=instance.id).exists()

You may also have to specify the field in the serializer's Meta class. When first run, the framework will tell you exactly how.

answered Sep 21, 2016 at 13:37

Brian

7,6733 gold badges30 silver badges48 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

Sierran Over a year ago

Thank you! Works like a charm! Only i get resposne for my second question and I can sleep peacefully :)

Brian Over a year ago

You can override the create() in your Comment's viewset. Pretty easy in the docs. Let me know if you run into any undocumented problems.

Sierran Over a year ago

Then i can save postId to post but api would return still {post: 1} not postId.. i try use Charfield with source = post but then I lost possibility to select related post from dropdown.

Collectives™ on Stack Overflow

Django Rest Framework return True if relation exist

1 Answer 1

3 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

3 Comments

Your Answer

Sign up or log in

Post as a guest

Related