Question

I am trying to use a polymorphic comment model on the post model , upload model, etc. Ordinarily i would have a @parent resource to scope one to the other in order for Rails to build the relationship. But because this a multi-tenant subdomain styled application, where all resources will also need to be scoped to the curent_account. I am struggling with how to scope @parent resource under the current_accout.

In ApplicationController I have a current_account method, a find_parent and a parent_collection method:

#Application_controller
class ApplicationController < ActionController::Base
  before_filter :current_account

  def current_account
    unless is_root_domain?
     @current_account ||= Account.find_by_subdomain(request.subdomains.first)
    end
  @current_account
  end

 def find_parent
   params.each do |name ,value|
    @parent = $1.pluralize.classify.constantize.find(value) if name =~ /(.*?)_id/
  return if @parent
  end
 end

 def parent_collection
   @parent_collection ||= current_account.send parent.pluralize
 end

end

#comments_controller with only @parent resource without reference to current_account
class CommentsController < ApplicationController
  before_filter :find_parent

  def new
    @comment = @parent.comments.build
  end

  def create
   @comment = @parent.comments.build(params[:comment])
   .....
   .....
  end
end

#comments_controller using only current_account resource without reference to @parent
class CommentsController < ApplicationController
  before_filter :current_account

  def new
    @comment = current_account.comments.build
  end

  def create
    @comment = current_account.comments.build(params[:comment])
    .....
    .....
  end
end

Any guide on how to call current_accout in the controllers in a way that @parent is scoped to it and is there a need for the parent_collection method that i put in the applications_controller. Thanks

Answer 1

Let’s make an assumption that your @parent resource is a Post model. Then I would imagine that:
a) your Account model has_many :posts
b) your Post model belongs_to :account
c) your Post model has_many :comments, :as => :commentable
c) your Comment model belongs_to :commentable, :polymorphic => true

So with that in mind you should be able to build scopes like this:

@parent.where(:account_id => current_account.id).comments

You can also refactor it to the commentable model:

def Post < ActiveRecord::Base
  scope :by_account, lambda { |account_id| where(:account_id => account_id) }
end

and the use it in the controller like this:

@parent.by_account(current_account.id).comments