URL/URI Validations in Rails

igrigorik (Ilya Grigorik) — Fri, 08 Sep 2006 07:56:59 GMT

Here is a quick/basic URI validation library for your Rails app:



require 'net/http'



# Original credits: http://blog.inquirylabs.com/2006/04/13/simple-uri-validation/

# HTTP Codes: http://www.ruby-doc.org/stdlib/libdoc/net/http/rdoc/classes/Net/HTTPResponse.html



class ActiveRecord::Base

  def self.validates_uri_existence_of(*attr_names)

    configuration = { :message => "is not valid or not responding", :on => :save, :with => nil }

    configuration.update(attr_names.pop) if attr_names.last.is_a?(Hash)

    

    raise(ArgumentError, "A regular expression must be supplied as the :with option of the configuration hash") unless configuration[:with].is_a?(Regexp)

    

    validates_each(attr_names, configuration) do |r, a, v|

        if v.to_s =~ configuration[:with] # check RegExp

              begin # check header response

                  case Net::HTTP.get_response(URI.parse(v))

                    when Net::HTTPSuccess then true

                    else r.errors.add(a, configuration[:message]) and false

                  end 

              rescue # Recover on DNS failures.. 

                  r.errors.add(a, configuration[:message]) and false

              end

        else

          r.errors.add(a, configuration[:message]) and false

        end 

    end

  end

end

Save the code above into a file in your 'lib' directory. ex: validates_uri_existence_of.rb. Include the file in your environment.rb (ex: require 'validates_uri_existence_of').

And now you can use the validator in any model by calling:



validates_uri_existence_of :url, :with =>

        /(^$)|(^(http|https)://[a-z0-9] ([-.]{1}[a-z0-9] )*.[a-z]{2,5}(([0-9]{1,5})?/.*)?$)/ix

Above code validates the URI/URL against a regular expression first, and then does a HEAD query to confirm that the page is alive (HTTPSuccess code is returned). You could easily modify the code to extend the functionality as you wish.

More info in this post.

DZone Snippets: Igrigorik's Code Snippets

URL/URI Validations in Rails