Add URL validation class.

config/environment.rb

@@ -3,3 +3,6 @@ require File.expand_path('../application', __FILE__)
 
 # Initialize the rails application
 WwwWhoisandrewCom::Application.initialize!
+
+# Include the URL validator
+require 'url_validator'

lib/url_validator.rb

@@ -0,0 +1,13 @@
+class UrlValidator < ActiveModel::EachValidator
+  def validate_each(record, attribute, value)
+    begin
+      uri = URI.parse(value)
+      resp = uri.kind_of?(URI::HTTP)
+    rescue URI::InvalidURIError
+      resp = false
+    end
+    unless resp == true
+      record.errors[attribute] << (options[:message] || "is not an url")
+    end
+  end
+end