Rails - Sanitize Ordering Params

example_controller.rb

class ExampleController
  include OrderingHelpers
  
  def index
    @clients = Clients.order(sanitized_ordering).where(user_id: current_user.id)
  end

end

ordering_helpers.rb

module OrderingHelpers
  extend ActiveSupport::Concern
  def sanitized_ordering
    "#{sanitize_column(params[:order_by])} #{sanitize_column_direction(params[:sort_direction])}"
  end

  private
  def sanitize_column(column)
    resource.column_names.include?(column) ? column : "created_at"
  end

  def sanitize_column_direction(direction)
    direction = direction.upcase
    ['DESC', 'ASC'].include?(direction) ? direction : "DESC"
  end

  def resource
    controller_name.camelize.singularize.safe_constantize
  end
end

FYI, I ended up extending ActiveRecord::Relation in order to create a sanitized_order() method that accepts the column and direction to sort on. It can be improved to work with other class column names, etc. but it does the job for now:

config/initializers/sanitized_order.rb

class ActiveRecord::Relation

  # This will sanitize the column and direction of the order. Should always be used when taking these params from GET.
  #
  def sanitized_order( column, direction = nil )
    direction ||= "ASC"

    raise "Column value of #{column} not permitted."       unless self.klass.column_names.include?( column.to_s ) 
    raise "Direction value of #{direction} not permitted." unless [ "ASC", "DESC" ].include?( direction.upcase ) 

    self.order( "#{column} #{direction}" )
  end

end

And then you simply call it in the query chain like:

Client.sanitized_order( params[:order_by], params[:sort_direction] ).where(user_id: current_user.id)