`Using` cause circular dependency

[larryzhao]

I have two simple models:

class User < ActiveRecord::Base
  has_many :notebooks, dependent: :destroy
  has_many :notes, :through => :notebooks
end

class Note < ActiveRecord::Base
  belongs_to :notebook
  has_one :user, :through => :notebook
end

module Entities
class Note < Grape::Entity
  expose :id, :title, :views_count, :slug

  expose :user, :using => Entities::User
end
end

And have two simple Entity for them. And in Entities::Note, I'd like to present user model using Entities::User with the syntax :using . But I found that it only works if I require the Entities::User file before the Entities::Note file. Other wise I will get an error saying: [:error, "undefined method `represent' for #Class:0x007fde9cecc4d0"]

Is there a good way to solve this? since I am also gonna present notes inside user.

Thank you very much.

[joelvh]

You could create base classes without the association on them and inherit those in the other classes....

module Entities
  class User < Grape::Entity
    expose :id, :name, :email
  end
  class Note < Grape::Entity
    expose :id, :title, :views_count, :slug
  end
end

module Entities
  class UserWithNotes < User
    expose :notes, :using => Entities::Note
  end

  class NoteWithUser < Note
    expose :user, :using => Entities::User
  end
end

Would that solve it for you?

[larryzhao]

@joelvh I don't think so. If there's a third Entity that want to use UserWithNotes and also need to be included in UserWithNotes, the problem is there again.

[dblock]

I think one possible way to fix this is to support symbol or string notation on the right-hand-side. For example

expose :user, :using => "Entities::User"
expose :user, :using => :user

I would take a PR for that.

[dblock]

Fixed in 856c9d0.