private

# File lib/public_suffix.rb, line 149
def self.decompose(name, rule)
  left, right = rule.decompose(name)

  parts = left.split(DOT)
  # If we have 0 parts left, there is just a tld and no domain or subdomain
  # If we have 1 part  left, there is just a tld, domain and not subdomain
  # If we have 2 parts left, the last part is the domain, the other parts (combined) are the subdomain
  tld = right
  sld = parts.empty? ? nil : parts.pop
  trd = parts.empty? ? nil : parts.join(DOT)

  Domain.new(tld, sld, trd)
end

Attempt to parse the name and returns the domain, if valid.

This method doesn’t raise. Instead, it returns nil if the domain is not valid for whatever reason.

@param name [#to_s] The domain name or fully qualified domain name to parse. @param list [PublicSuffix::List] The rule list to search, defaults to the default {PublicSuffix::List} @param ignore_private [Boolean] @return [String]

# File lib/public_suffix.rb, line 140
def self.domain(name, **options)
  parse(name, **options).domain
rescue PublicSuffix::Error
  nil
end

Pretend we know how to deal with user input.

# File lib/public_suffix.rb, line 164
def self.normalize(name)
  name = name.to_s.dup
  name.strip!
  name.chomp!(DOT)
  name.downcase!

  return DomainInvalid.new("Name is blank") if name.empty?
  return DomainInvalid.new("Name starts with a dot") if name.start_with?(DOT)
  return DomainInvalid.new(format("%s is not expected to contain a scheme", name)) if name.include?("://")

  name
end

Parses name and returns the {PublicSuffix::Domain} instance.

@example Parse a valid domain

PublicSuffix.parse("google.com")
# => #<PublicSuffix::Domain:0x007fec2e51e588 @sld="google", @tld="com", @trd=nil>

@example Parse a valid subdomain

PublicSuffix.parse("www.google.com")
# => #<PublicSuffix::Domain:0x007fec276d4cf8 @sld="google", @tld="com", @trd="www">

@example Parse a fully qualified domain

PublicSuffix.parse("google.com.")
# => #<PublicSuffix::Domain:0x007fec257caf38 @sld="google", @tld="com", @trd=nil>

@example Parse a fully qualified domain (subdomain)

PublicSuffix.parse("www.google.com.")
# => #<PublicSuffix::Domain:0x007fec27b6bca8 @sld="google", @tld="com", @trd="www">

@example Parse an invalid (unlisted) domain

PublicSuffix.parse("x.yz")
# => #<PublicSuffix::Domain:0x007fec2f49bec0 @sld="x", @tld="yz", @trd=nil>

@example Parse an invalid (unlisted) domain with strict checking (without applying the default * rule)

PublicSuffix.parse("x.yz", default_rule: nil)
# => PublicSuffix::DomainInvalid: `x.yz` is not a valid domain

@example Parse an URL (not supported, only domains)

PublicSuffix.parse("http://www.google.com")
# => PublicSuffix::DomainInvalid: http://www.google.com is not expected to contain a scheme

@param name [#to_s] The domain name or fully qualified domain name to parse. @param list [PublicSuffix::List] The rule list to search, defaults to the default {PublicSuffix::List} @param ignore_private [Boolean] @return [PublicSuffix::Domain]

@raise [PublicSuffix::DomainInvalid] If domain is not a valid domain. @raise [PublicSuffix::DomainNotAllowed] If a rule for domain is found, but the rule doesn’t allow domain.

# File lib/public_suffix.rb, line 67
def self.parse(name, list: List.default, default_rule: list.default_rule, ignore_private: false)
  what = normalize(name)
  raise what if what.is_a?(DomainInvalid)

  rule = list.find(what, default: default_rule, ignore_private: ignore_private)

  # rubocop:disable Style/IfUnlessModifier
  if rule.nil?
    raise DomainInvalid, "`#{what}` is not a valid domain"
  end
  if rule.decompose(what).last.nil?
    raise DomainNotAllowed, "`#{what}` is not allowed according to Registry policy"
  end

  # rubocop:enable Style/IfUnlessModifier

  decompose(what, rule)
end

Checks whether domain is assigned and allowed, without actually parsing it.

This method doesn’t care whether domain is a domain or subdomain. The validation is performed using the default {PublicSuffix::List}.

@example Validate a valid domain

PublicSuffix.valid?("example.com")
# => true

@example Validate a valid subdomain

PublicSuffix.valid?("www.example.com")
# => true

@example Validate a not-listed domain

PublicSuffix.valid?("example.tldnotlisted")
# => true

@example Validate a not-listed domain with strict checking (without applying the default * rule)

PublicSuffix.valid?("example.tldnotlisted")
# => true
PublicSuffix.valid?("example.tldnotlisted", default_rule: nil)
# => false

@example Validate a fully qualified domain

PublicSuffix.valid?("google.com.")
# => true
PublicSuffix.valid?("www.google.com.")
# => true

@example Check an URL (which is not a valid domain)

PublicSuffix.valid?("http://www.example.com")
# => false

@param name [#to_s] The domain name or fully qualified domain name to validate. @param ignore_private [Boolean] @return [Boolean]

# File lib/public_suffix.rb, line 123
def self.valid?(name, list: List.default, default_rule: list.default_rule, ignore_private: false)
  what = normalize(name)
  return false if what.is_a?(DomainInvalid)

  rule = list.find(what, default: default_rule, ignore_private: ignore_private)

  !rule.nil? && !rule.decompose(what).last.nil?
end