Returns the domain part of a host given the domain level.

# Top-level domain example
extract_domain('www.example.com', 1) # => "example.com"
# Second-level domain example
extract_domain('dev.www.example.co.uk', 2) # => "example.co.uk"

# File actionpack/lib/action_dispatch/http/url.rb, line 20
def extract_domain(host, tld_length)
  extract_domain_from(host, tld_length) if named_host?(host)
end

Returns the subdomains of a host as a String given the domain level.

# Top-level domain example
extract_subdomain('www.example.com', 1) # => "www"
# Second-level domain example
extract_subdomain('dev.www.example.co.uk', 2) # => "dev.www"

# File actionpack/lib/action_dispatch/http/url.rb, line 44
def extract_subdomain(host, tld_length)
  extract_subdomains(host, tld_length).join('.')
end

Returns the subdomains of a host as an Array given the domain level.

# Top-level domain example
extract_subdomains('www.example.com', 1) # => ["www"]
# Second-level domain example
extract_subdomains('dev.www.example.co.uk', 2) # => ["dev", "www"]

# File actionpack/lib/action_dispatch/http/url.rb, line 30
def extract_subdomains(host, tld_length)
  if named_host?(host)
    extract_subdomains_from(host, tld_length)
  else
    []
  end
end

Returns the domain part of a host, such as “rubyonrails.org” in “www.rubyonrails.org”. You can specify a different tld_length, such as 2 to catch rubyonrails.co.uk in “www.rubyonrails.co.uk”.

# File actionpack/lib/action_dispatch/http/url.rb, line 356
def domain(tld_length = @@tld_length)
  ActionDispatch::Http::URL.extract_domain(host, tld_length)
end

Returns the host for this request, such as example.com.

class Request < Rack::Request
  include ActionDispatch::Http::URL
end

req = Request.new 'HTTP_HOST' => 'example.com:8080'
req.host # => "example.com"

# File actionpack/lib/action_dispatch/http/url.rb, line 247
def host
  raw_host_with_port.sub(/:\d+$/, ''.freeze)
end

Returns a host:port string for this request, such as “example.com” or “example.com:8080”.

class Request < Rack::Request
  include ActionDispatch::Http::URL
end

req = Request.new 'HTTP_HOST' => 'example.com:80'
req.host_with_port # => "example.com"

req = Request.new 'HTTP_HOST' => 'example.com:8080'
req.host_with_port # => "example.com:8080"

# File actionpack/lib/action_dispatch/http/url.rb, line 263
def host_with_port
  "#{host}#{port_string}"
end

Returns a number port suffix like 8080 if the port number of this request is not the default HTTP port 80 or HTTPS port 443.

class Request < Rack::Request
  include ActionDispatch::Http::URL
end

req = Request.new 'HTTP_HOST' => 'example.com:80'
req.optional_port # => nil

req = Request.new 'HTTP_HOST' => 'example.com:8080'
req.optional_port # => 8080

# File actionpack/lib/action_dispatch/http/url.rb, line 330
def optional_port
  standard_port? ? nil : port
end

Returns the port number of this request as an integer.

class Request < Rack::Request
  include ActionDispatch::Http::URL
end

req = Request.new 'HTTP_HOST' => 'example.com'
req.port # => 80

req = Request.new 'HTTP_HOST' => 'example.com:8080'
req.port # => 8080

# File actionpack/lib/action_dispatch/http/url.rb, line 278
def port
  @port ||= begin
    if raw_host_with_port =~ /:(\d+)$/
      $1.to_i
    else
      standard_port
    end
  end
end

Returns a string port suffix, including colon, like “:8080” if the port number of this request is not the default HTTP port 80 or HTTPS port 443.

class Request < Rack::Request
  include ActionDispatch::Http::URL
end

req = Request.new 'HTTP_HOST' => 'example.com:80'
req.port_string # => ""

req = Request.new 'HTTP_HOST' => 'example.com:8080'
req.port_string # => ":8080"

# File actionpack/lib/action_dispatch/http/url.rb, line 346
def port_string
  standard_port? ? '' : ":#{port}"
end

Returns 'https://' if this is an SSL request and 'http://' otherwise.

class Request < Rack::Request
  include ActionDispatch::Http::URL
end

req = Request.new 'HTTP_HOST' => 'example.com'
req.protocol # => "http://"

req = Request.new 'HTTP_HOST' => 'example.com', 'HTTPS' => 'on'
req.protocol # => "https://"

# File actionpack/lib/action_dispatch/http/url.rb, line 216
def protocol
  @protocol ||= ssl? ? 'https://' : 'http://'
end

Returns the host for this request, such as “example.com”.

class Request < Rack::Request
  include ActionDispatch::Http::URL
end

req = Request.new 'HTTP_HOST' => 'example.com'
req.raw_host_with_port # => "example.com"

req = Request.new 'HTTP_HOST' => 'example.com:8080'
req.raw_host_with_port # => "example.com:8080"

# File actionpack/lib/action_dispatch/http/url.rb, line 231
def raw_host_with_port
  if forwarded = x_forwarded_host.presence
    forwarded.split(/,\s?/).last
  else
    get_header('HTTP_HOST') || "#{server_name || server_addr}:#{get_header('SERVER_PORT')}"
  end
end

Returns the standard port number for this request's protocol.

class Request < Rack::Request
  include ActionDispatch::Http::URL
end

req = Request.new 'HTTP_HOST' => 'example.com:8080'
req.standard_port # => 80

# File actionpack/lib/action_dispatch/http/url.rb, line 296
def standard_port
  case protocol
    when 'https://' then 443
    else 80
  end
end

Returns whether this request is using the standard port

class Request < Rack::Request
  include ActionDispatch::Http::URL
end

req = Request.new 'HTTP_HOST' => 'example.com:80'
req.standard_port? # => true

req = Request.new 'HTTP_HOST' => 'example.com:8080'
req.standard_port? # => false

# File actionpack/lib/action_dispatch/http/url.rb, line 314
def standard_port?
  port == standard_port
end

Returns all the subdomains as a string, so "dev.www" would be returned for “dev.www.rubyonrails.org”. You can specify a different tld_length, such as 2 to catch "www" instead of "www.rubyonrails" in “www.rubyonrails.co.uk”.

# File actionpack/lib/action_dispatch/http/url.rb, line 372
def subdomain(tld_length = @@tld_length)
  ActionDispatch::Http::URL.extract_subdomain(host, tld_length)
end

Returns all the subdomains as an array, so ["dev", "www"] would be returned for “dev.www.rubyonrails.org”. You can specify a different tld_length, such as 2 to catch ["www"] instead of ["www", "rubyonrails"] in “www.rubyonrails.co.uk”.

# File actionpack/lib/action_dispatch/http/url.rb, line 364
def subdomains(tld_length = @@tld_length)
  ActionDispatch::Http::URL.extract_subdomains(host, tld_length)
end

Returns the complete URL used for this request.

class Request < Rack::Request
  include ActionDispatch::Http::URL
end

req = Request.new 'HTTP_HOST' => 'example.com'
req.url # => "http://example.com"

# File actionpack/lib/action_dispatch/http/url.rb, line 201
def url
  protocol + host_with_port + fullpath
end