I’m using the collectiveidea fork of DelayedJob. There are two ways to create a DelayedJob record. First you can use the delay method.

Second way to create DelayedJob records is custom jobs.

If you have been hacking ruby for a while you should have heard that “Everything is an object”. To understand this concept knowing what a singleton class is important. Yehuda Katz’s post is a good source for it.

My ruby version 1.9.2.

First I’m going to show you how to add methods to instances by using define_method.

You can also write an instance method to create instance methods. send must be used because define_method is private.

Write a singleton method to create instance methods.

Now it is time to add singleton methods. When we call define_method, it creates an instance method. What we have to do is call define_method on class’ singleton class.

Getting singleton class of a class:

First defining singleton method to create singleton methods.

Then defining instance method to create singleton methods.

Rails 2.3 has a good solution for multi model forms. But there is not much examples of  how to use accepts_nested_attributes_for with has_one relation.

Assume that we have a Book model which has one Author.

Controller :

View:

No special action is needed for create method of BooksController,  attr_accessible is not necessary for Book model. Just don’t forget to add the second parameter (@book) of form_for and build your nested object (@book.build_author).

If you have trouble when converting string to array, check if your string includes any line feed (\n). Check how Array("string") behaves:

irb(main):001:0> Array("izzet emre \nkutlu")
=> ["izzet emre \n", "kutlu"]

This output is not what most of the people expected. Be careful!

If you have recently updated to Rails 2.2.2, you may encounter this error when you want to start your application:

/.gem/ruby/1.8/gems/activesupport-2.2.2/lib/active_support/dependencies.rb:445:in
`load_missing_constant': uninitialized constant Inflector (NameError)

As I learned from Paul’s post usage of Inflector class is changed a bit. You can see the difference when you compare the inflections.rb files. Path of the file is yourApp/config/initializers/inflections.rb

inflections.rb (Rails 2.1.0)

 Inflector.inflections do |inflect|
  .
  .
  .
 end

inflections.rb (Rails 2.2.2)

 ActiveSupport::Inflector.inflections do |inflect|
  .
  .
  .
 end

In my situation changing Inflector to ActiveSupport::Inflector was enough to solve the problem.