gistfile1.rb

LOOKUP_CHAIN = [:params, :user, :session, :http, :default]

def self.set_by(inputs)
  locale = nil
  LOOKUP_CHAIN.each do |lookup|
    locale = send("by_#{lookup}", inputs[lookup])
    break if locale
  end
  return locale
end

Here’s a refactoring:

module Enumerable
  def find_mapped
    result = nil
    self.each do |lookup|
      result = yield(lookup)
      break if result
    end
    return result
  end
end

LOOKUP_CHAIN = [:params, :user, :session, :http, :default]

def self.set_by(inputs)
  LOOKUP_CHAIN.find_mapped do |lookup|
    locale = send("by_#{lookup}", inputs[lookup])
  end
end

It produces the same output in the test harness I posted previously.

Oh, and sorry for the 4-space indentation in that previous test-harness code. I forgot to convert from tabs to spaces, and GitHub won’t let me edit that comment.

I made a Gist fork for my refactoring that I just posted.

I just found out that you can make more than one fork of a Gist. So here’s a Gist fork for the test harness I posted earlier.

This Gist was posted alongside a tweet by the author:

Any ideas to refactor this little ruby collection operation? https://gist.github.com/3247167

Thought about this the other day but just got around to trying it this afternoon. I believe #any? stops when it reaches a truthy result, so how about this:

def self.set_by(inputs)
  locale = nil
  LOOKUP_CHAIN.any? { |lookup| locale = send("by_#{lookup}", inputs[lookup]) }
  return locale
end

Passes the test harness.