add cookie support to response

This commit adds support for response cookies. Response now has a method
cookie to fetch the current cookie. One cookie has multiple crumbs which
represent a key value pair. For each crumb multiple options can be set
according to the specs.

2 files changed, 125 insertions, 6 deletions

diff --git a/lib/zero/response.rb b/lib/zero/response.rb
index ab4acde..cb58cfe 100644
--- a/lib/zero/response.rb
+++ b/lib/zero/response.rb
@@ -1,3 +1,5 @@
+require 'zero/response/cookie'
+
 module Zero
   # This is the representation of a response
   class Response
@@ -10,18 +12,17 @@ module Zero
 
     # Constructor
     # Sets default status code to 200.
-    #
     def initialize
       @status = 200
       @header = {}
       @body   = []
+      @cookies = {}
     end
 
     # Sets the status.
     # Also converts every input directly to an integer.
     #
     # @param [Integer] status The status code
-    #
     def status=(status)
       @status = status.to_i
     end
@@ -53,8 +54,8 @@ module Zero
     # Removes Content-Type, Content-Length and body on status code 204 and 304.
     #
     # @return [Array] Usable by webservers
-    #
     def to_a
+      add_cookie_headers
       # Remove content length and body, on status 204 and 304
       if status == 204 or status == 304
         header.delete('Content-Length')
@@ -72,7 +73,6 @@ module Zero
 
     # Sets the content length header to the current length of the body
     # Also creates one, if it does not exists
-    #
     def content_length
       self.header['Content-Length'] = body.join.bytesize.to_s
     end
@@ -81,7 +81,6 @@ module Zero
     # Also creates it, if it does not exists
     #
     # @param [String] value Content-Type tp set
-    #
     def content_type=(value)
       self.header['Content-Type'] = value
     end
@@ -89,10 +88,25 @@ module Zero
     # Sets the Location header to the given URL and the status code to 302.
     # 
     # @param [String] location Redirect URL
-    #
     def redirect(location, status = 302)
       self.status = status
       self.header['Location'] = location
     end
+
+    # get the cookie for the response
+    #
+    # This returns the cookie holding all crumbs for the response.
+    # @response [Cookie] the cookie with crumbs holding the information
+    def cookie
+      @cookie ||= Cookie.new
+    end
+
+    private
+
+    # merge the cookie header into the other headers
+    def add_cookie_headers
+      return unless @cookie
+      header.merge!(cookie.to_header)
+    end
   end
 end
diff --git a/lib/zero/response/cookie.rb b/lib/zero/response/cookie.rb
new file mode 100644
index 0000000..45ef65f
--- /dev/null
+++ b/lib/zero/response/cookie.rb
@@ -0,0 +1,105 @@
+module Zero
+  class Response
+    class Cookie
+      # initialize an empty cookie
+      def initialize
+        @crumbs = {}
+      end
+
+      # add a new crumb
+      #
+      # This adds a new crumb to the cookie specified through the key.
+      # @param key [String] the identifier for the crumb
+      # @param value [String] the value for the crumb
+      # @param options [Hash] hash with further options for the crumb
+      # @option options [Time]   :expire the time when the crumb should expire
+      # @option options [String] :domain the domain the crumb should be sent to
+      # @option options [String] :path   path when the crumb should be sent
+      # @option options [Array]  :flags set flags for :secure or :http_only
+      def add_crumb(key, value, options = {:flags => []})
+        @crumbs[key] = Crumb.new(key, value, options)
+      end
+
+      # get the crumb for the key
+      #
+      # This method returns the crumb for the specified key. The crumb holds all
+      # information, like the expire time and domain and so on.
+      # @param key [String] the key to return
+      # @returns [Cookie::Crumb] a cookie crumb or nil when the key
+      #                             does not exist
+      def get_crumb(key)
+        @crumbs[key]
+      end
+
+      # merge all crumbs to one header line
+      #
+      # This merges all crumbs together to a header line, where each cookie is
+      # separated by the `Set-Cookie` header.
+      # @returns [Hash] a key value pair to merge with the headers
+      def to_header
+        {'Set-Cookie' => @crumbs.map{|key, crumb| crumb}.join("\nSet-Cookie: ")}
+      end
+      
+      private
+
+      class Crumb
+        attr_reader :key, :secure, :http_only
+        attr_accessor :domain, :path, :expire, :value
+
+        def initialize(key, value, options = {})
+          options[:flags] ||= []
+          @key       = key
+          @value     = value
+          @domain    = options[:domain]
+          @expire    = options[:expire]
+          @path      = options[:path]
+          @secure    = options[:flags].include?(:secure)
+          @http_only = options[:flags].include?(:http_only)
+        end
+
+        # set the `http_only` flag
+        #
+        # This method sets the flag to only allow modifications from the
+        # server and makes the browser not allow modifications through
+        # javascript.
+        def deny_client_side_modification!
+          @http_only = true
+        end
+
+        # remove the `http_only` flag
+        #
+        # This removes the `http_only` flag to allow modifications of the
+        # crumb through javascript.
+        def allow_client_side_modification!
+          @http_only = false
+        end
+
+        # set the `secure` flag
+        #
+        # This sets the `secure` flag on the crumb which tells the browser to
+        # only send it through secure channels, like https.
+        # Keep in mind, that this does not encrypt the content of the Crumb!
+        def secure!
+          @secure = true
+        end
+
+        # unset the `secure` flag
+        #
+        # This unsets the `secure` flag which tells the browser, that it can
+        # send the crumb over unsecure channel too, like plain http.
+        def unsecure!
+          @secure = false
+        end
+
+        def to_s
+          "#{@key}=#{@value}" +
+            (@expire ? "; Expires=#{@expire.rfc2822}" : '') +
+            (@path   ? "; Path=#{@path}" : '') +
+            (@domain ? "; Domain=#{domain}" : '') +
+            (@http_only ? '; HttpOnly' : '') +
+            (@secure    ? '; Secure' : '')
+        end
+      end
+    end
+  end
+end