Add HTTP::Cookie#set_cookie_value, and alias #cookie_value to #to_s.

README.md

@@ -23,6 +23,10 @@ Or install it yourself as:
 
 ## Usage
 
+    ########################
+    # Client side example
+    ########################
+
     # Initialize a cookie jar
     jar = HTTP::CookieJar.new
 
@@ -30,15 +34,30 @@ Or install it yourself as:
     jar.load(filename) if File.exist?(filename)
 
     # Store received cookies
-    HTTP::Cookie.parse(set_cookie_header_value, :origin => uri) { |cookie|
+    HTTP::Cookie.parse(set_cookie_header_value, origin: uri) { |cookie|
       jar << cookie
     }
 
-    # Extract cookies to send
-    cookie_value_to_send = jar.cookies(uri).join(', ')
+    # Get the value for the Cookie field of a request header
+    cookie_header_value = jar.cookies(uri).join(', ')
 
     # Save to a file
-    jar.save_as(filename)
+    jar.save(filename)
+
+
+    ########################
+    # Server side example
+    ########################
+
+    # Generate a cookie
+    cookies = HTTP::Cookie.new("uid", "a12345", domain: 'example.org',
+                                                for_domain: true,
+                                                path: '/',
+                                                max_age: 7*86400)
+
+    # Get the value for the Set-Cookie field of a response header
+    set_cookie_header_value = cookies.set_cookie_value(my_url)
+
 
 ## To-Do list
 

lib/http/cookie.rb

@@ -385,21 +385,12 @@ class HTTP::Cookie
     acceptable_from_uri?(uri) && normalize_path(uri.path).start_with?(@path)
   end
 
-  def to_s
+  # Returns a string for use in a Cookie header value,
+  # i.e. "name=value".
+  def cookie_value
     "#{@name}=#{@value}"
   end
-
-  # Compares the cookie with another.  When there are many cookies with
-  # the same name for a URL, the value of the smallest must be used.
-  def <=>(other)
-    # RFC 6265 5.4
-    # Precedence: 1. longer path  2. older creation
-    (@name <=> other.name).nonzero? ||
-      (other.path.length <=> @path.length).nonzero? ||
-      (@created_at <=> other.created_at).nonzero? ||
-      @value <=> other.value
-  end
-  include Comparable
+  alias to_s cookie_value
 
   # Serializes the cookie into a cookies.txt line.
   def to_cookiestxt_line(linefeed = "\n")
@@ -414,6 +405,50 @@ class HTTP::Cookie
     ].join("\t") << linefeed
   end
 
+  # Returns a string for use in a Set-Cookie header value.  If the
+  # cookie does not have an origin set, one must be given from the
+  # argument.
+  #
+  # This method does not check if this cookie will be accepted from
+  # the origin.
+  def set_cookie_value(origin = nil)
+    origin = origin ? URI(origin) : @origin or
+      raise "origin must be specified to produce a value for Set-Cookie"
+
+    string = cookie_value
+    if @for_domain || @domain != DomainName.new(origin.host).hostname
+      string << "; domain=#{@domain}"
+    end
+    if (normalize_uri_path(origin) + './').path != @path
+      string << "; path=#{@path}"
+    end
+    if expires = @expires
+      string << "; expires=#{@expires.httpdate}"
+    end
+    if comment = @comment
+      string << "; comment=#{@comment}"
+    end
+    if httponly?
+      string << "; HttpOnly"
+    end
+    if secure?
+      string << "; secure"
+    end
+    string
+  end
+
+  # Compares the cookie with another.  When there are many cookies with
+  # the same name for a URL, the value of the smallest must be used.
+  def <=>(other)
+    # RFC 6265 5.4
+    # Precedence: 1. longer path  2. older creation
+    (@name <=> other.name).nonzero? ||
+      (other.path.length <=> @path.length).nonzero? ||
+      (@created_at <=> other.created_at).nonzero? ||
+      @value <=> other.value
+  end
+  include Comparable
+
   # YAML serialization helper for Syck.
   def to_yaml_properties
     PERSISTENT_PROPERTIES.map { |name| "@#{name}" }

test/test_http_cookie.rb

@@ -369,6 +369,27 @@ class TestHTTPCookie < Test::Unit::TestCase
     end
   end
 
+  def test_set_cookie_value
+    url = URI.parse('http://rubyforge.org/')
+    cookie_params = @cookie_params.merge('secure' => 'secure')
+    cookie_value = 'foo=bar'
+
+    cookie_params.keys.combine.each do |keys|
+      cookie_text = [cookie_value, *keys.map { |key| cookie_params[key] }].join('; ')
+      cookie, = HTTP::Cookie.parse(cookie_text, :origin => url)
+      cookie2, = HTTP::Cookie.parse(cookie.set_cookie_value, :origin => url)
+
+      assert_equal(cookie.name, cookie2.name)
+      assert_equal(cookie.value, cookie2.value)
+      assert_equal(cookie.domain, cookie2.domain)
+      assert_equal(cookie.for_domain?, cookie2.for_domain?)
+      assert_equal(cookie.path, cookie2.path)
+      assert_equal(cookie.expires, cookie2.expires)
+      assert_equal(cookie.secure?, cookie2.secure?)
+      assert_equal(cookie.httponly?, cookie2.httponly?)
+    end
+  end
+
   def test_parse_cookie_no_spaces
     url = URI.parse('http://rubyforge.org/')
     cookie_params = @cookie_params