regexp and rails validations - ruby-on-rails

Question

I have two customs validations :
def validate_email
regexp = "[A-Za-z0-9._%+-]+#[A-Za-z0-9.-]+\.[A-Za-z]+"
if sleep_email.present? && !sleep_email.match(regexp)
errors.add(:sleep_email, "l'email indiqué semble ne pas avoir le bon format")
end
end
def validate_website
regexp = "(http:\/\/www\.|https:\/\/www\.|http:\/\/|https:\/\/)?[a-z0-9]+([\-\.]{1}[a-z0-9]+)*\.[a-z]{2,5}(:[0-9]{1,5})?(\/.*)?"
if website.present? && !website.match(regexp)
errors.add(:website, "l'url de votre site web doit avoir la forme de http://votresite.com")
end
end
But yo#yo and http://website are valids. What's wrong ?

Answer 1

You're building regexes using strings. Strings and regexes have different quoting. You're effectively double escaping. Things like \. are turned into a plain ..
# This results in the regex /a.c/
p "abc".match?("a\.c") # true
# This results in the desired regex /a\.c/
p "abc".match?("a\\.c") # true
# This avoids the string escaping entirely.
p "abc".match?(%r{a\.c}) # false
To avoid this double escaping, use /.../ or %r{...} to create regexes.
Don't try to validate email with a regex. Instead, use the validates_email_format_of gem which provides a proper validator you can use on any attribute.
validates :sleep_email, presence: true, email_format: true
If you want to see how to fully validate an email address, look at the source.
Your URL regex does work.
regexp = "(http:\/\/www\.|https:\/\/www\.|http:\/\/|https:\/\/)?[a-z0-9]+([\-\.]{1}[a-z0-9]+)*\.[a-z]{2,5}(:[0-9]{1,5})?(\/.*)?"
p "http://website".match?(regexp) # true
http://website is valid URL syntax. It's not URL's job to check the validity of the host.
If you also want to validate parts of the URL your regex will get increasingly complex. Instead, parse the URL with URI and then check its individual pieces as you like.
Here's a custom validator I whipped up which parse the URI, checks it's an allowed scheme, and does a very rudimentary check on the host.
class UrlValidator < ActiveModel::EachValidator
ALLOWED_SCHEMES = ['http', 'https']
private def allowed_schemes
options[:allowed_schemes] || ALLOWED_SCHEMES
end
def validates_each(record, attribute, value)
uri = URI(value)
if !allowed_schemes.include?(uri.scheme)
record.errors.add(attribute, :scheme_not_allowed, message: "Scheme #{uri.scheme} is not allowed")
end
# Has to have at least xxx.yyy
# This is a pretty sloppy host check.
if !uri.host.match?(/\w+\.\w+/)
record.errors.add(attribute, :host_not_allowed, message: "Host #{uri.host} is not allowed")
end
rescue URI::Error
record.errors.add(attribute, :not_a_uri)
end
end
validates :website, url: true
If you wanted to allow other schemes, like ftp...
validates :website, url: { allowed_schemes: ['http', 'https', 'ftp'] }
If you wanted true domain validation, you could add a DNS lookup.
begin
Resolv::DNS.open do |dns|
dns.getaddress(uri.host) }
end
rescue Resolv::ResolvError
record.errors.add(attribute, :invalid_host, { message: "#{uri.host} could not be resolved" }
end
However, this lookup has a performance impact.

Answer 2

The standard email regex (RFC 5322 Official Standard) to use is:
(?:[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*|"(?:[\x01-\x08\x0b\x0c\x0e-\x1f\x21\x23-\x5b\x5d-\x7f]|\\[\x01-\x09\x0b\x0c\x0e-\x7f])*")#(?:(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?|\[(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?|[a-z0-9-]*[a-z0-9]:(?:[\x01-\x08\x0b\x0c\x0e-\x1f\x21-\x5a\x53-\x7f]|\\[\x01-\x09\x0b\x0c\x0e-\x7f])+)\])
As for the website URL, use this one. The URL will only be valid if the TLD (.com, .net, etc.) is included.
^(http|https):\/\/[a-z0-9]+([\-\.]{1}[a-z0-9]+)*\.[a-z]{2,5}(:[0-9]{1,5})?(\/.*)?$