CODEWITHSUNDEEP
ruby-on-railsregexvalidationdnsformat
Trent Scott
Trent Scott

Reputation: 2028

Ruby on Rails URL Validation (regex)

I'm trying to use a regular expression to validate the format of a URL in my Rails model. I've tested the regex in Rubular with the URL http://trentscott.com and it matched.

Any idea why it fails validation when I test it in my Rails app (it says "name is invalid").

Code:

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

  validates :serial, :presence => true
  validates :name, :presence => true,
                   :format    => {  :with => url_regex  }

Upvotes: 5

Views: 11613

Answers (5)

Premanandh Selvakumarasamy
Premanandh Selvakumarasamy

Reputation: 1362

Try this.

It's working for me. 

/(ftp|http|https):\/\/(\w+:{0,1}\w*@)?(\S+)(:[0-9]+)?(\/|\/([\w#!:.?+=&%@!\-\/]))?/

Upvotes: 1

danneu
danneu

Reputation: 9454

(I like Thomas Hupkens' answer, but for other people viewing, I'll recommend Addressable)

It's not recommended to use regex to validate URLs.

Use Ruby's URI library or a replacement like Addressable, both of which making URL validation trivial. Unlike URI, Addressable can also handle international characters and tlds.

Example Usage:

require 'addressable/uri'

Addressable::URI.parse("кц.рф") # Works

uri = Addressable::URI.parse("http://example.com/path/to/resource/")
uri.scheme
#=> "http"
uri.host
#=> "example.com"
uri.path
#=> "/path/to/resource/"

And you could build a custom validation like:

class Example
  include ActiveModel::Validations

  ##
  # Validates a URL
  #
  # If the URI library can parse the value, and the scheme is valid
  # then we assume the url is valid
  #
  class UrlValidator < ActiveModel::EachValidator
    def validate_each(record, attribute, value)
      begin
        uri = Addressable::URI.parse(value)

        if !["http","https","ftp"].include?(uri.scheme)
          raise Addressable::URI::InvalidURIError
        end
      rescue Addressable::URI::InvalidURIError
        record.errors[attribute] << "Invalid URL"
      end
    end
  end

  validates :field, :url => true
end

Code Source

Upvotes: 10

Maged Makled
Maged Makled

Reputation: 1986

This will include an international host handling as well like abc.com.it where the .it part is optional

match '/:site', to: 'controller#action' , constraints: { site: /[a-zA-Z0-9][a-zA-Z0-9-]{1,61}[a-zA-Z0-9]\.[a-zA-Z]{2,}(.[a-zA-Z]{2,63})?/}, via: :get, :format => false

Upvotes: 0

cordsen
cordsen

Reputation: 1701

Your input ( http://trentscott.com) does not have a subdomain but the regex is checking for one.

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

Update

You also don't need the ? after ((http|https):\/\/) unless the protocol is sometimes missing. I've also escaped . because that will match any character. I'm not sure what the grouping above is for, but here is a better version that supports dashes and groups by section 

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

Upvotes: 7

Thomas Hupkens
Thomas Hupkens

Reputation: 1590

You don't need to use a regexp here. Ruby has a much more reliable way to do that:

# Use the URI module distributed with Ruby:

require 'uri'

unless (url =~ URI::regexp).nil?
    # Correct URL
end

(this answer comes from this post:)

Upvotes: 14

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