# Overriding a single Rails core file (batches.rb) **URL:** \ **Category:** Rails\ **Created:** [September 25, 2009, 1:49am UTC](https://www.ruby-forum.com/t/overriding-a-single-rails-core-file-batches-rb/176127 "2009-09-25T01:49:36Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![Sebastian\_von\_Conra](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/da6949/32.png) [@Sebastian\_von\_Conra](https://www.ruby-forum.com/u/Sebastian_von_Conra)\ **Post date:** [September 25, 2009, 1:49am UTC](https://www.ruby-forum.com/t/overriding-a-single-rails-core-file-batches-rb/176127/1 "2009-09-25T01:49:36Z")
Hi everyone, I’m trying to find a way to implement a diff I found into my application ([Tickets - Ruby on Rails - rails](https://rails.lighthouseapp.com/projects/8994/tickets/) 2137-allow-find\_batches-to-use-order-limit-and-offset). It is imperative that I use find\_in\_batches as well as passing an :order option to the function. Certain rows need to be processed before others, and because of the size of the table I can’t do them all at once. Now, my question is, how could I do this with the least amount of fuss? I don’t want to edit the batches.rb in my Rails installation, as I then would have to do the same on servers and other workstations. I also don’t particularly want to freeze Rails. I’ve tried just slapping a new batches.rb into /vendor/rails/activerecord/lib/active\_record/, hoping that that would override just that file, but it doesn’t seem to work. Any help would be appreciated! Best regards, Sebastian ---
**Author:** ![Sebastian\_von\_Conra](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/da6949/32.png) [@Sebastian\_von\_Conra](https://www.ruby-forum.com/u/Sebastian_von_Conra)\ **Post date:** [September 25, 2009, 3:14am UTC](https://www.ruby-forum.com/t/overriding-a-single-rails-core-file-batches-rb/176127/2 "2009-09-25T03:14:29Z")
Colin, Thanks! I will most likely go with option 2. Can I just copy-paste the modified methods as per the diff into any of those directories (obviously with “module ActiveRecord” and “module Batches” at the top)? Do I need to adhere to a specific naming scheme for the file? Apologies for all the questions. I’m still (re-)learning Rails. Best regards, Sebastian ---
**Author:** ![Sebastian\_von\_Conra](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/da6949/32.png) [@Sebastian\_von\_Conra](https://www.ruby-forum.com/u/Sebastian_von_Conra)\ **Post date:** [September 25, 2009, 3:07am UTC](https://www.ruby-forum.com/t/overriding-a-single-rails-core-file-batches-rb/176127/3 "2009-09-25T03:07:28Z")
Sebastian, Since it’s an ActiveRecord module that gets included into AR::Base, you either need to: 1. (Sneaky) Load your own Batches module when AR wants to autoload it (active\_record.rb:51) - override Module#autoload to ‘listen’ for the Batches module, and substitute your version (located in /lib or something) instead. You’ll have to do this before Rails loads AR, though, so put it in /config/preinitializer.rb. 2. (More sane) Monkey-patch the changed methods into AR::B through a file you include in /lib, /config/initializers or through your own plugin. You would probably be overriding #find\_in\_batches, #sort\_batch\_rows! and #select\_batch\_ids. 3. Freeze rails, replace the file. This is the simplest, and least error-prone, though upgrading and patching Rails may be trickier. Colin On Thu, Sep 24, 2009 at 4:47 PM, Sebastian von Conrad ---
**Author:** ![Sebastian\_von\_Conra](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/da6949/32.png) [@Sebastian\_von\_Conra](https://www.ruby-forum.com/u/Sebastian_von_Conra)\ **Post date:** [September 25, 2009, 4:03am UTC](https://www.ruby-forum.com/t/overriding-a-single-rails-core-file-batches-rb/176127/4 "2009-09-25T04:03:04Z")
Nevermind, figured it out. Thanks again! - Sebastian On Sep 25, 10:12 am, Sebastian von Conrad