Rails 3.2 Extending String Core Classe as per Rails doc

[Erwin]

As per Rails doc ( http://guides.rubyonrails.org/plugins.html#extending-core-classes )

my app being yoodle

I  added in yoodle/lib

yoodle.rb

    require "yoodle/core_ext"

    module Yoodle

    end

in yoodle/lib/my_app/core_ext

  String.class_eval do

    def to_squawk

      "squawk! #{self}".strip

    end

  end

and I have added in yoodle/config/application.rb

    config.autoload_paths += Dir["#{config.root}/lib", "#{config.root}/lib/**/"]

but running in console

> "AAA".to_squawk   raises an error

NoMethodError: undefined method `to_squawk' for "AAA":String

Is there anything else not mentionned in the Rails doc ?

[Jordon Bedwell]

On Tue, Nov 20, 2012 at 10:46 AM, Erwin <yves_...@mac.com> wrote:
> in yoodle/lib/my_app/core_ext
> String.class_eval do
> def to_squawk
> "squawk! #{self}".strip
> end
> end
>
> and I have added in yoodle/config/application.rb
> config.autoload_paths += Dir["#{config.root}/lib",
> "#{config.root}/lib/**/"]
>
> but running in console
>> "AAA".to_squawk raises an error
> NoMethodError: undefined method `to_squawk' for "AAA":String
>
> Is there anything else not mentionned in the Rails doc ?

1.) Autloading is for constants not for anything else and it's
preferable you use autoload_once_paths instead of autoload_paths (at
least from my experience, others may differ on opinion and I don't
have any evidence to back up my claims other than what the name
implies and threading and what not.)

2.) Do not class_eval directly onto String, that's bad business,
monkey patching that way is a dirty dirty game and to most it's an
eternal sin... make your own module and do `String.send(:include,
MyModule)` because at least then there is a clear path back to where
it comes from, in your case nobody has any damn idea where the code
comes from therefore they have no real idea how to path it out at all.

__OPINION__

Normally what I do is one method per file patching and one include
file per patch w/ a generic all called patches.rb in the root of lib
that will load all the patches at once, but the former allows people
who take my code to pull specific code without having to dig, I am a
big fan of easy to follow code and code that is designed to be
decoupled (meaning my patches should not rely on each other and I
should be able to include a single and only a single patch if that's
what I want.) This means that I would do:

lib/my_app/core_ext/string/to_squawk.rb < The Patch.
lib/patches/stdlib/string/to_squawk.rb < The file that Patches String.
Here is an example: https://gist.github.com/5984753b60573f416820

__OPINION__

Now, most probably won't like the way I work with my patches some
people love to patch up STDLib like it's their day job and sole job
description so if you don't then what you need to do is just require
the file (lib is included in your load path by default in Rails) and
the patch will work but I think you should still fix that whole dirty
dirty way of patching in your method.

[Erwin]

Thanks Jordon for your comments .. I appreciate your feedback

just to mention that all this stuff is from Rails latest doc ...  that's why I needed some clarification before going further

so I just duplicated the Rails doc code into my app for testing ... and 

1- it doesn't run 

2- seems to be bad way as per your comment

can you clarify your comment # 2  taking this sample core_ext ?

are the created files correct ?  if yes , why the core_ext doesn't get loaded at all ?

[Frederick Cheung]

On Tuesday, November 20, 2012 4:46:56 PM UTC, Erwin wrote:

and I have added in yoodle/config/application.rb

    config.autoload_paths += Dir["#{config.root}/lib", "#{config.root}/lib/**/"]

but running in console

> "AAA".to_squawk   raises an error

NoMethodError: undefined method `to_squawk' for "AAA":String

autoload_paths is the set of paths that can be autoloaded - they won't actually be loaded on startup in development mode (although they would be in production).

The example in the doc is written from the point of view of writing the extension as part of a gem, in wich case lib/yaffle gets loaded for you by bundler. You seem to be adding this straight to your app, so you don't get this behaviour. The simplest thing is probably to add an initializer that requires yoodle.rb for you 

Fred

[Frederick Cheung]

On Tuesday, November 20, 2012 5:26:53 PM UTC, Jordon Bedwell wrote:

1.) Autloading is for constants not for anything else and it's
preferable you use autoload_once_paths instead of autoload_paths (at
least from my experience, others may differ on opinion and I don't
have any evidence to back up my claims other than what the name
implies and threading and what not.)

The difference between autoload_paths and autoload_once_paths is that in the development the former can be reloaded between requests whereas the latter will not. Which one is prefererable depends on what you're doing, although of course the reloading behaviour is handy if those files are under active development. That doesn't really work when the purpose of the file is to patch a core class that can't itself be reloaded

Fred

[Erwin]

Thanks Fred for this clear feedback ...

I did it  (added require 'yoodle.rb'  in my  initializers/configuration.rb)  and it works ...

:-)))