Comments for pluginaweek's state_machine  

Re-opened #28 at Lighthouse, this has some unintended side effects: http://pluginaweek.lighthouseapp.com/projects/13288-state_machine/tickets/28-loopback-transitions-dont-appear-to-update-rails-record#ticket-28-4

Thanks. Fixed: http://github.com/pluginaweek/state_machine/commit/e8bd70499c573d667101cecc72548f1516c8f14c

s/unqalified/unqualified/

I think I see what is going on here, there is a special case for initialize such that it does not appear as an instance method, and alias_method does not respect the special case.

I was surprised because I often use define_method to define instance methods. i see now the issue has to do with aliasing.

Thanks!

p.s. Have you seen this alternative to alias_method?

Also, the reason behind this change is that Rails will spit out warnings when reloading in development mode because it sees “initialize” as an instance method and removes it from the class.

It’s very subtle, indeed, even though the comment is out of date.

Using class_eval/define_method techniques:

class A
  def initialize
  end
end

A.class_eval do
  alias_method :initialize_without_something, :initialize
  define_method(:initialize) do
    initialize_without_something
  end
end
A.instance_methods.include?(‘initialize’) # => false

Using aliasing:

class A
  def initialize
  end
end

A.class_eval do
  alias_method :initialize_without_something, :initialize
  def initialize_with_something
  end
  alias_method :initialize, :initialize_with_something
end
A.instance_methods.include?(‘initialize’) # => true

That comment was meant as a reminder for why define_method was being used instead of an alias technique.

define_method is used to prevent it from showing up in #instance_methods: Perhaps I do not understand what you mean. When I use #define_method in Ruby 1.8.7, the name of the method I define shows up when I call #instance_methods on the class.

Is there some subtlety I am missing here with respect to 1.8.6? Or to calling #define_method in a module? Or something else?

Awesome! Looks like a great predicates implementation.

Keep up the good work!

This patch is a real nipple rubber. You rule, Nate!

I think I said I was going to do this three days ago. I love GitHub…

Brilliant change. I used this to implement fine gained cache expiry for comments in Shopify and it fit like a glove.