Active_model_serializers: Filtering fields on included associations

[typhoon2099]

I have a serializer which includes a belongs_to to another serializer. In my controller I want to specify the fields that the associated serializer returns. How do I do this? I have the following serializers:

class ProductSerializer < ActiveModel::Serializer
  belongs_to :user
  attributes :id, :name, :locked, :visible
end

class UserSerializer < ActiveModel::Serializer
  attributes :id, :email, :name, :locked, :phone, :show_welcome
end

The following in my controller does not seem to work:

render json: @product, include: [:user], fields: [
  :id, :name, :locked, :visible,
  user: [:name, :email],
]

This does not work, however, and my user field returns back all of its fields.

[typhoon2099]

My current workaround is to add a new attribute to ProductSerializer:

  attribute :user do
    {
      name: object.user.name,
      email: object.user.email,
    }
  end

But this feel like a hack to get around something I'm not fully grasping.

[wasifhossain]

can you please make sure you are using the 0-10-stable HEAD

[wasifhossain]

@typhoon2099 do you have any further updates on this? thanks

[typhoon2099]

Not yet, I've been working on other things. I'll give this a go and report back soon.

[typhoon2099]

I've just added 0-10-stable to my project and the situation seems to be the same as before. I can't seem to find much in the way of documentation around it but is it possible to limit the fields in the serializer? Eg:

class ProductSerializer < ActiveModel::Serializer
  belongs_to :user, fields: [:name, :email]
  attributes :id, :name, :locked, :visible
end

That kind of thing?

[wasifhossain]

@typhoon2099 0-10-stable HEAD should support this feature. You can take a look at the test here: https://github.com/rails-api/active_model_serializers/blob/0-10-stable/test/adapter/json/fields_test.rb#L55

It should work for both :json and :attributes adapter in the same way, and for :json_api adapter in its own way.

Fields doc: https://github.com/rails-api/active_model_serializers/blob/0-10-stable/docs/general/fields.md

Let me know how it goes.

[typhoon2099]

No, it doesn't seem to work, all the fields defined in UserSerializer are still being included. The tested code is the same as in my first comment.

[wasifhossain]

closing the issue due to lack of further data related to debugging the case. Reiterating that the feature is now supported as mentioned in this issue.

the main comment: https://github.com/rails-api/active_model_serializers/issues/2330#issuecomment-490095465

[wasifhossain]

feel free to open the issue again with necessary data that would help in debugging the case.

[duyetpt]

I encounted the bug in version 0.10.6 with adapter attributes.

[wasifhossain]

@duyetpt can you please follow https://github.com/rails-api/active_model_serializers/issues/2330#issuecomment-489741918 and see if you still find the issue.

If yes, we would appreciate detailed info to help us debugging the case. Thanks!

[duyetpt]

When use version 0.10.6 or 0.10.9, i still encounter the bugs. I check code and see that, code in tag 0.10.6 and 0.10.9 is out date. After that, i try use gem with follow define:

gem 'active_model_serializers', git: 'https://github.com/rails-api/active_model_serializers', branch: '0-10-stable'

It worked for me.

[wasifhossain]

yes because the issue was fixed recently after 0.10.9 was released.

[duyetpt]

yeah, thanks @wasifhossain.

[wasifhossain]

you're welcome! @duyetpt