To_sub_domain

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        Converts any string into something that could be used as a sub domain

Usage:
  "asdf as dfa sdf dsf".to_sub_domain
  "asdf-as-dfa-sdf-dsf"

#object_mixins.rb
class Object
  
  def to_sub_domain
    #thanks to kipp howard for the much more readable regex tips

    #convert spaces to "-"
    a = /\s/
    #remove leading and trailing "-"
    #b = /^-*([a-z0-9][a-z0-9\-]{0,}[a-z0-9]{1})-*$/
    b = /^-*(\w+[a-z0-9\-]*\w)-*$/
    #remove all other characters
    c = /[^a-z0-9\-]/
    #remove all -------
    d = /^-*$/
    self.to_s.strip.downcase.gsub(a,'-').gsub(b,'\1').gsub(c,'').gsub(b,'\1').gsub(d,'')
  end

end

Rspec tests

# -*- coding: utf-8 -*-
require File.dirname(__FILE__) + '/../spec_helper'
require 'object_mixins'

def bad_sub_domains
  [" asdf ", "$92sadf-94%", "*", "", "  ", "----", "asdf ", " - ", "-", "this quick brown fox, ran up the hill", "\n",
    " - asdf-eieie%%  pwpwp    f------------ ", "-asdf-", "asdf-", "-asdf"]
end

def bad_sub_domains_converted
  ["asdf", "92sadf-94",     "",  "", "",   "",     "asdf",  "",    "",  "this-quick-brown-fox-ran-up-the-hill",   "",
    "asdf-eieie--pwpwp----f", "asdf", "asdf", "asdf"]
end

def good_sub_domains
  ["123", "123-123", "a1", "a", "1", "a-a", "i-am-10-feet-short"]
end

describe 'Test to_sub_domain in object_mixins' do

  bad_sub_domains.each do |s| 
    it "should convert [#{s}] to [#{bad_sub_domains_converted[bad_sub_domains.index(s)]}]" do
      #puts "[#{s.to_sub_domain}] to [#{bad_sub_domains_converted[bad_sub_domains.index(s)]}]"
      assert s.to_sub_domain == bad_sub_domains_converted[bad_sub_domains.index(s)]
    end
  end
  
end

Tags:
• domain
• expression
• Rails
• regex
• regular
• rspec
• Ruby
• sub