Question

I have the following models:

class Post < ActiveRecord::Base
   has_many :responses, as: :responseable, dependent: :destroy
end

class Call < ActiveRecord::Base
   has_many :responses, as: :responseable, dependent: :destroy
end

class Meeting < ActiveRecord::Base
   has_many :responses, as: :responseable, dependent: :destroy
end

class Response < ActiveRecord::Base
   belongs_to :responseable, polymorphic: true # Tested
end

In CanCan I am trying to define the abilities on a specific custom Responses action via attributes in the polymorphic association. The action looks like this:

class ResponsesController < ApplicationController

  before_filter :authenticate_user!
  load_and_authorize_resource

  respond_to :html, :xml, :js, :json, :pdf


  # GET /responses/polling
  # GET /responses/polling.json
  def polling
    responseable_type = params[:responseable_type]
    klass = [Post, Call, Meeting].detect { |c| responseable_type}
    @responseable = klass.find(params[:responseable_id])
    undivided_millisecond_epoch_time_in_integer = params[:after]
    undivided_millisecond_epoch_time_in_decimal = (undivided_millisecond_epoch_time_in_integer).to_d
    divided_millisecond_epoch_time_in_decimal = (undivided_millisecond_epoch_time_in_decimal / 1000000).to_d
    @responses = @responseable.responses.where("created_at > ?", Time.at(divided_millisecond_epoch_time_in_decimal))
  end
...

This action is run via a javascript function that polls for new responses every 5 seconds. However, when this runs I get the following errors in the log:

A NameError occurred in responses#polling:

  uninitialized constant Responseable
  activesupport (3.2.8) lib/active_support/inflector/methods.rb:230:in `block in constantize'

Any idea the right way to define these types of abilities?

Answer 1

You made quite a mess in that controller, try to follow REST (or CRUD for that matter).

Anyway, Cancan wont be able to detect which resource you are trying to authorize. Try something like this:

load_resource :post
load_resource :call
load_resource :meeting
load_and_authorize_resource :response, :through => [:post, :call, :meeting]