Validation for URL/Domain using Regex? (Rails)

Question

I am trying to create a validation that checks to make sure a domain/url is valid for example \"test.com\"

def valid_domain_name?
  domain_name = domain.spli         


        

Answer 1

Better answer since Ruby 1.8.6

require 'uri'

def valid_url?(url)
  url.slice(URI::regexp(%w(http https))) == url
end

Answer 2

@Tate's answer is good for a full URL, but if you want to validate a domain column, you don't want to allow the extra URL bits his regex allows (e.g. you definitely don't want to allow a URL with a path to a file).

So I removed the protocol, port, file path, and query string parts of the regex, resulting in this:

^[a-z0-9]+([\-\.]{1}[a-z0-9]+)*\.[a-z]{2,5}$

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Check out the same test cases for both versions.

• Original (allows domains or full URLs): http://rubular.com/r/qGInC06jcz
• Modified (allows only domains): http://rubular.com/r/yP6dHFEhrl

Answer 3

Another way to do URL validation in Rails is

validates :web_address, :format => { :with => URI::regexp(%w(http https)), :message => "Valid URL required"}

Answer 4

Stumbled on this:

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

FYI: Rubular is a fantastic resource for testing your Ruby regular expressions

Answer 5

^(([a-zA-Z]{1})|([a-zA-Z]{1}[a-zA-Z]{1})|([a-zA-Z]{1}[0-9]{1})|([0-9]{1}[a-zA-Z]{1})|([a-zA-Z0-9][a-zA-Z0-9-_]{1,61}[a-zA-Z0-9]))\.([a-zA-Z]{2,6}|[a-zA-Z0-9-]{2,30}\.[a-zA-Z]{2,3})$

Domain name validation with RegEx

Answer 6

I took what you had and modified it so that I could make the http:// or https:// optional:

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