Ruby DSL Trick with the Hash

Today I had to rig up a method for defining symlinks in Capistrano. I never really liked how the ln command worked to begin with; I think of symlinks in terms of:

Alias A targets File B

To make this easier I wrote up this method:

def link(link)
   source, target = link.keys.first, link.values.first
   run "ln -nfs #{target} #{source}"
 end

Which reads as:

link "alias_a" => "file_b"

I love finding these little ways that make my code more readable.

Loading mentions Retweet

Oct 08, 2009

Sam Nardoni said...

I'll be using this. Nice work.

_dato said...

I'm using this in my Rails template:

def copy(files)
files.each do |from, to|
file(to, File.read(File.join(@template_path, from)))
end
end

copy 'layout.html.erb' => 'app/views/layouts/application.html.erb'

Very nifty.

grimen said...

DRYer =)

def link(link)
source, target = *link.first
run "ln -nfs #{target} #{source}"
end

Brad’s Musings

Fans of this post