# 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 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`](http://api.rubyonrails.org/classes/ActiveRecord/Validations/ClassMethods.html#M001052) 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](http://henrik.nyh.se/) 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.