Create route helpers for your controllers. Helpful for nested controllers.

gistfile1.rb

module RouteHelpers
  extend ActiveSupport::Concern

  module ClassMethods
    def create_resource_helpers(*params)
      @resource_params = params
      @resource_classes = params.select{|t| t.kind_of?(Class)}
      define_resource
      define_resource_class
      
      define_resource_params
      define_resource_path
      define_collection_path
      define_new_resource_path
      define_edit_resource_path
      helper_method :resource, :resource_class, :resource_params
      helper_method :resource_path, :collection_path, :new_resource_path, :edit_resource_path
      
      if @resource_classes.size >= 2
        define_parent_class
        define_parent
        define_parent_path
        
        helper_method :parent_class, :parent, :parent_path
      end
    end
    def set_resource_params(parms)
      @resource_params = parms
    end
    
    def define_resource_params
      params = @resource_params.map{|t| t.kind_of?(Symbol) ? t.inspect : "@#{t.name.underscore}"}
      class_eval "
      def resource_params
        [#{params.join(', ')}]
      end
      "
    end
    
    def define_resource
      class_eval "
      def resource
        @#{@resource_classes[-1].name.underscore}
      end
      "
    end
    
    def define_resource_class
      class_eval "
      def resource_class
        #{@resource_classes[-1]}
      end
      "
    end
    
    def define_parent_class
      class_eval "
      def parent_class
        #{@resource_classes[-2]}
      end
      "
    end
    
    def define_parent
      class_eval "
      def parent
        @#{@resource_classes[-2].name.underscore}
      end
      "
    end
    
    def define_parent_path
      @params = @resource_params.dup
      @params.pop
      @params.pop if @params.last.kind_of?(Symbol)
      
      class_eval "
      def parent_path(params={})
        #{@params.map{|t| t.to_s.underscore}.join('_')}_path(parent, params)
      end
      "
    end
    
    def define_collection_path
      @params = @resource_params.dup
      # @params.pop
      # @params.pop if @params.last.kind_of?(Symbol)
      
      class_eval "
      def collection_path(params={})
        #{@params.map{|t| t.to_s.underscore}.join('_')}_path(parent, params)
      end
      "
    end

    def define_resource_path
      @params = @resource_params.dup
      method_name = "#{@params.map{|t| t.to_s.underscore}.join('_')}_path"
      
      class_eval "
      def resource_path(*args)
        if args[0].kind_of?(resource_class)
          #{method_name}(parent, args[0], args[1])
        else
          #{method_name}(parent, resource, args[0])
        end
      end
      "
    end

    def define_edit_resource_path
      @params = @resource_params.dup
      method_name = "edit_#{@params.map{|t| t.to_s.underscore}.join('_')}_path"
      
      class_eval "
      def edit_resource_path(*args)
        if args[0].kind_of?(resource_class)
          #{method_name}(parent, args[0], args[1])
        else
          #{method_name}(parent, resource, args[0])
        end
      end
      "
    end

    def define_new_resource_path
      @params = @resource_params.dup
      
      class_eval "
      def new_resource_path(params={})
        new_#{@params.map{|t| t.to_s.underscore}.join('_')}_path(parent, resource, params)
      end
      "
    end
  end
end