Nested _destroy attribute with Mongoid and strong_parameters

Question

I'd like to destroy documents from an embeds_many relationship using a request attribute.

class Experience
  include Mongoid::Document

  embeds_many :variations, class_name: 'ExperienceVariation'
  accepts_nested_attributes_for :variations, allow_destroy: true
end

class ExperiencesController < ApplicationController
  def update
    if @experience.update_attributes(experience_params)
      show
    else
      render json: @experience.andand.errors, status: :unprocessable_entity
    end
  end

  def experience_params
    params.require(:experience).permit(
      ...
      variations: [
        :id, :delete, ...
      ]
    )
  end
end

When making a request with _destroy , I get the error:

Mongoid::Errors::UnknownAttribute - 
Problem:
  Attempted to set a value for '_destroy' which is not allowed on the model ExperienceVariation.

How can I get nested _destroy to work?

Answer 1

Everything turned out to be fine on the Rails side. It was in the front-end (AngularJS) that the request was sending variations rather than variations_attributes .