Filterable

filterable.rb

# Call scopes directly from your URL params:
#
#     @products = Product.filter(params.slice(:status, :location, :starts_with))
module Filterable
  extend ActiveSupport::Concern

  module ClassMethods
    
    # Call the class methods with names based on the keys in <tt>filtering_params</tt>
    # with their associated values. For example, "{ status: 'delayed' }" would call 
    # `filter_by_status('delayed')`. Most useful for calling named scopes from 
    # URL params. Make sure you don't pass stuff directly from the web without 
    # whitelisting only the params you care about first!
    def filter(filtering_params)
      filtering_params.reject {|key, value| value.blank? }.reduce(self.where(nil)) {|scope, (key, value)| scope.public_send("filter_by_#{key}", value) }
    end
  end
end