A Little RAILS_ROOT Tidiness

Ever write code like this in Rails?

[sourcecode language='ruby']
if File.exists?(File.join(RAILS_ROOT, 'config', 's3.yml'))
has_attached_file :s3_image,
:storage => :s3,
:s3_credentials => File.join(RAILS_ROOT, 'config', 's3.yml')
end
[/sourcecode]

That particular snippet is from an application that optionally uses Amazon S3 to store images, if there is a configuration file for S3 supplied in the deployment. Well, you can clean that up a bit. First, although the RAILS_ROOT constant is still supported, we've had the prettier-looking Rails.root for months. Second, as of a recent commit to edge rails, Rails.root returns a Pathname object, so it directly supports the join method. Hence, the code snippet above can now be:

[sourcecode language='ruby']
if File.exists?(Rails.root.join('config', 's3.yml'))
has_attached_file :s3_image,
:storage => :s3,
:s3_credentials => Rails.root.join('config', 's3.yml')
end
[/sourcecode]

A tiny improvement, but of such tiny improvements are a pleasant framework made.

Comments

[Mark Wilden]

Nice tip. I'd stick Rails.root.join('config', 's3.yml') in a local variable instead of repeating it.

[Dan Kubb]

Pathname is IMHO one of the more useful, but most underused libraries. It makes working work files alot simpler than using the File class directy.

Although I'd probably tend to write that example using the Pathname#exists? method instead of File.exists?, like this: http://pastie.org/332348

[Mike Gunderloy]

The nicest thing about posting code samples: instant code review. Thanks, good changes both.

[ChrisR]

1. File.join() - which all developers will only understand

or

2. Rails.root.join() - which will only make sense to rails developers

I think its a pointless change that makes it slightly cleaner, but less understandable overall.