Rails posting to a custom action on a nested polymorphic resource

I am unable to get the "like" action to work.

I am basing my action on the Raiscast no 364:

http://ift.tt/NbOPyK

I believe my problem lies with the route:

resources :polls do
  resources :likes, only: [], defaults => { :likeable => 'poll' } do
    member { post :like }
  end    
end

Has defined the following route:

like_poll_like POST   /polls/:poll_id/likes/:id/like(.:format)             likes#like {:likeable=>"poll"}

I see here that the route is looking for an id for both the poll and the like however the controller action is to create a new row for in the likes table for the poll so there is no id for the like.

My like controller is:

class LikesController < ApplicationController
  before_filter :load_likeable

  def like
    like = @likeable.likes.new(value: params[:value], user_id: current_user)
    if like.save
      redirect_to :back, notice: "Thank you for voting."
    else
      redirect_to :back, alert: "Unable to vote, perhaps you already did."
    end
  end

  private

    def like_params
      params.require(:like).permit(:value)
    end

    def load_likeable
      resource, id = request.path.split('/')[3,4]
      @likeable = resource.singularize.classify.constantize.find(id)
    end

    def likeable_id
      params[(params[:likeable].singularize + "_id").to_sym]
    end

  end

Here is the helper I am unable to get to work:

<%= link_to "Click here", polymorphic_url(poll, action: :like, value: 1), method: "post" %> to vote for <%= poll.option %>

This returns the following error:

undefined method `like_poll_url' for #<#<Class:0x007f4dbf3d4668>:0x007f4dbf308ba8>

I do not want to move the like action into the polls controller as likes is polymorphic and the same functionality will be reused.