2dc_jqgrid + rails3

users_controller.rb

class UsersController < ApplicationController
  extend ActiveSupport::Memoizable
  ...

  def index
    @@index_columns ||= ['username', 'email', 'comments']

    @users = User.scoped
    if params[:_search] == "true"
      @@index_columns.each do |param|
        if params[param].present?
          @users = @users.where(param.matches("%#{params[param]}%"))
        end
      end
    end
    if order_by
      @users = @users.order(order_by)
    end

    @users = @users.paginate(:page => params[:page], :per_page => params[:rows] || 10)

    respond_to do |format|
      format.html
      format.json do
        render :json => @users.to_jqgrid_json(
          @@index_columns,
          params[:page], params[:rows], @users.total_entries
        )
      end
    end
  end

  private

    def order_by
      if sort_index and sort_order
        sort_index + " " + sort_order
      else
        nil
      end
    end

    def sort_index
      if @@index_columns.include?(params[:sidx])
        params[:sidx]
      else
        nil
      end
    end

    def sort_order
      if %w[asc desc].include?(params[:sord])
        params[:sord]
      else
        nil
      end
    end

    memoize :order_by, :sort_index, :sort_order
end