mgreenly

    #------------------------------------------------------------------------------------------------------------------
    #  type       name                  description
    #------------------------------------------------------------------------------------------------------------------
    #  int        iTotalRecords         Total records, before filtering (i.e. the total number of records in
    #                                   the database)
    #
    #  int        iTotalDisplayRecords  Total records, after filtering (i.e. the total number of records after
    #                                   filtering has been applied - not just the number of records being returned
    #                                   in this result set)
    #

mgreenly

    def render(object)
      receiver = object
      accessors = accessor.split(".")
      while accessor = accessors.shift
        if receiver.class.reflect_on_association(accessor.to_sym)
          receiver = receiver.send(accessor)
        else
          return receiver.send(accessor)
        end
      end

mgreenly

# 1. data table subclass is initialized
#   class methods are going to be called on the class instance, and the class will store table data
#
# 2. instantiate an instance of the data table subclass ( OrdersIndex.new)
#
# 3. query the instance w/ pagination and sorting params
#    a query gets executed w/ params -> ARel
#    results get stored  -> AR
#    results get passed back as json
class DataTable

mgreenly

class Foo
  # create class instance variables
  class << self; 
    attr_accessor :bar; 
  end

  #initialize class instance variables
  @bar = 42

  # use class instance variables in class methods

mgreenly

require 'spec_helper'

describe 'Data tables subclasses' do

  # it 'should work' do
  #   Order.create!(:order_number => 32)
  #   data_table = OrdersIndex.new
  #   params = {}
  #   json = data_table.query(params).json
  #   json['aaRecords'][0][0].should == 32

mgreenly

# apps/data_tables/orders_index.rb
class OrdersIndex < DataTable
  model Order
  column :order_number, :width => 300
  joins :customer
    column :first_name
    column :last_name
  end
  column :memo
  order [:memo, :first_name]

mgreenly

# undefine the class if it's defined
Object.send(:remove_const, :OrderExample) rescue nil

# define the class
class OrderExample < DataTable
  set_model Order
  column :id
  column :order_number
  joins :customer do
    column :first_name

mgreenly

dealers = Dealer.arel_table
sales_reps = SalesRep.arel_table
dealer_counts = dealers.
                group(dealers[:sales_rep_id]).
                where(dealers[:deleted_at].eq(nil)).
                where(dealers[:ended].eq(nil)).
                project(dealers[:sales_rep_id], dealers[:id].count.as('value'))

def left_outer_join(subselect,as,on)
 result = Arel.sql("")

mgreenly

def next
  loop do 
    if cache.empty?
      cache.concat(next_block)
      if cache.empty?
        nil
      else
        redo
      end
    else

mgreenly

class Datatable::Base
  #....
    include ActionView::Helpers::UrlHelper
    include ActionView::Helpers::TagHelper
    def method_missing(symbol, *args, &block)
      if symbol.to_s =~ /(path|url)$/
        return Rails.application.routes.url_helpers.send(symbol, *args)
      end
      super(symbol, *args, &block)
    end