Rails helper method with external classes -

i going try , explain best way can...so here go...

here old(working) controller truck. sorts columns , asc/desc orders works intended.

class truckscontroller < applicationcontroller   # /trucks   # /trucks.json   require 'sort_methods'   helper_method :sort_column, :sort_direction   def index     @trucks = truck.search(params[:search]).order(sortmethods.sort_column(truck, "truck_no", params[:sort]) + " " + sortmethods.sort_direction(params[:direction]))      respond_to |format|       format.html # index.html.erb       format.json { render json: @trucks }     end   end  private    def sort_column     truck.column_names.include?(params[:sort]) ? params[:sort] : "truck_no"   end    def sort_direction     %w[asc desc].include?(params[:direction]) ? params[:direction] : "asc"   end end 

from understand helper_method here called when page passed no arguments, has default can revert , sort methods below methods cause default behavior. works intended, can load pages , sort.

now @ trucks calling class in lib has identical methods sort_methods because call methods multiple times , i'm trying dry code this. works, still because i've done class in way:

class sortmethods   def self.sort_column(table, field, sort)     table.column_names.include?(sort) ? sort : field   end    def self.sort_direction(direction)     %w[asc desc].include?(direction) ? direction : "asc"   end end 

alright code works intended, problem repeating sort methods twice, in controller , in sortmethods class. set default helper class using sortmethods if try call using code:

helper_method :sortmethods.sort_column(truck, "truck_no", params[:sort]), sortmethods.sort_direction(params[:direction]) 

i receive following message:

undefined local variable or method `sort_column' #<#<class:0x1a3a780>:0x1852f08> 

my assumption 1 of variables passing in nil, can't figure out 1 , how go avoid problem? there way can default if no parameters set in place. tried moving helper in index gives me error:

undefined method `sort_column' :sortmethods:symbol 

helper_method makes given method accessible inside controller views. hence, don't need specify sortmethods methods helper, because not part of controller. should able call them in view like

sortmethods.sort_column(blah) 

also, keep definition of sortmethods class? if in file sort_methods.rb anywhere in app folder, can skip require on top, rails automatically search (it part of constant_missing method)