active_model_serializers: JSONAPI - Wrong "type" for belongs_to polymorphic relationships

Expected behavior vs actual behavior

For JSONAPI, after this pr is merged: #1857, type parameter returns the relation type, instead of resource type.

Steps to reproduce

serializer:

class CommentSerializer < ActiveModel::Serializer
  # ....
  belongs_to :commentable # post, image etc.
end

request: /comments?include=commentable

expected:

//...
"relationships": {
  "commentable": {
    "data": {
      "id": "1",
      "type": "posts"
    }
  }
}
//...

result:

//...
"relationships": {
  "commentable": {
    "data": {
      "id": "1",
      "type": "commentables"
    }
  }
}
//...

Environment

ActiveModelSerializers Version, after this: #1857

About this issue

Original URL
State: closed
Created 7 years ago
Reactions: 8
Comments: 23 (8 by maintainers)

Most upvoted comments

This do not solve the problem but as a workaround in your application you could change your belong_to :field, polymorphic: true to has_one :field, polymorphic: true and the type returned will be ok.

I tried to solve the problem… it seems like we should access attribute #{name}_type on polymorphic relationships on parent object, but on ::ActiveModel::Serializer::Reflection initialize method parent object is not initialized.

j-arnaiz on Jul 6, 2017

I cannot envision a single way OJ might change this behavior 🤔

beauby on Jun 30, 2017

@andyhite

I get the feeling the maintainers of active_model_serializers don’t care that it’s broken. It’s been busted for at least 5 months, and no activity on the repo since.

More of just that maintainers tend to scratch their own itch, and I’ve been busy doing other things and no one has fixed it yet. Maybe part of the problem is ego because I worked really hard on the code in between 0.10.5 and 0.10.6 and don’t really want to yank it. I’d rather fix it. But I need help.

bf4 on Oct 4, 2017

@bf4 sorry, I didn’t mean to come across as rude as I did. It’s just a pretty big issue and makes 0.10.6 unusable for a lot of people. I understand you worked hard on the code between 0.10.5 and 0.10.6, which should be good reason to fix it so we can all reap the benefits of 0.10.6, haha.

I spent about a day trying to figure it out, and came up with the band-aid I mentioned in a comment back in June (which I’m unfortunately running in production via my fork), but it unfortunately isn’t a complete solution and breaks something that I’m not currently using (can’t remember what, off the top of my head) - so it’s fine for my case, but not something that can be merged upstream.

andyhite on Oct 4, 2017

Having same issue. Downgraded to 0.10.5

leadingproperties on Jul 25, 2017

having same issue, passing custom type: :versions but it still as model.table_name

ajahongir on Jul 17, 2017

My temporary hack to fix this is the following:

# lib/active_model_serializers/adapter/json_api/relationship.rb:49
type = association.reflection.type ? association.reflection.type.to_s : association.lazy_association.serializer.json_key

# lib/active_model/serializer/reflection.rb:59-60
options[:class_name] ? options[:class_name].underscore.pluralize.to_sym : nil

I haven’t tested anything other than my case though, so I’m not comfortable pull requesting it yet.

andyhite on Jun 30, 2017