validates_url_format_of

Rails plugin that provides a validates_url_format_of method to ActiveRecord models. URLs are validated by regexp.

Known to be compatible with Ruby 1.8 and 1.9.2.

Known to be compatible with ActiveRecord 3.0.0.beta, 2.3.5, 2.2.2, 2.1.2.

Usage

After installing the plugin, it's used like

class User < ActiveRecord::Base
  validates_url_format_of :url,
                          :allow_nil => true,
                          :message => 'is completely unacceptable'
end

Takes the same arguments as validates_format_of except for the :with regexp.

The default :message is different depending on whether the attribute name contains the word "URL". So you will get "Homepage URL does not appear to be valid" but "Homepage does not appear to be a valid URL" without having to customize the :message.

Please note that the regexp used to validate URLs is not perfect, but hopefully good enough. See the test suite. Patches are very welcome.

Limitations and design choices

Does not handle IPv6.

By design, the plugin does not allow e.g. "http://localhost" or "http://my.localurl", which are valid URLs but not suitable in most web apps. It also requires a "http://" or "https://" prefix, so just "example.com" is not valid. Fix that in the setter.

Credits and license

By Henrik Nyh under the MIT license:

Copyright (c) 2008 Henrik Nyh

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.