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.split(".")
  name = /(?:[A-Z0-9\-])+/.match(domain_name[0]).nil?
  tld = /(?:[A-Z]{2}|aero|ag|asia|at|be|biz|ca|cc|cn|com|de|edu|eu|fm|gov|gs|jobs|jp|in|info|me|mil|mobi|museum|ms|name|net|nu|nz|org|tc|tw|tv|uk|us|vg|ws)/.match(domain_name[1]).nil?
  if name == false or tld == false
    errors.add(:domain_name, 'Invalid domain name. Please only use names with letters (A-Z) and numbers (0-9).')
  end
end

This is what I have so far but it doesn't work. It lets bad URLs through without failing.

I don't know regex very well.

Answer 1

偶然发现:

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

仅供参考:Rubular是测试Ruby正则表达式的绝佳资源

Answer 2

@Tate的答案适用于完整的URL,但如果要验证domain列,则不希望允许其正则表达式允许的额外URL位(例如,您绝对不希望允许带有路径的URL文件).

所以我删除了正则表达式的协议,端口,文件路径和查询字符串部分,结果如下:

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

查看两个版本的相同测试用例.

• 原始(允许域名或完整网址):http://rubular.com/r/qGInC06jcz
• 修改(仅允许域):http://rubular.com/r/yP6dHFEhrl

Answer 3

^(http|https):\/\/|[a-z0-9]+([\-\.]{1}[a-z0-9]+)*\.[a-z]{2,6}(:[0-9]{1,5})?(\/.*)?$/ix

• example.com
• sub.example.com
• sub.domain.my-example.com
• example.com/?stuff=true
• example.com:5000/?stuff=true
• sub.domain.my-example.com/path/to/file/hello.html
• hello.museum
• http://railsgirls.com

http://rubular.com/r/cdkLxAkTbk

添加了可选的http://或https://

最长的顶级域名.museum,有6个字符......

Answer 4

在Rails中进行URL验证的另一种方法是

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

Answer 5

自Ruby 1.8.6以来更好的答案

require 'uri'

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