Facilitates the chain of responsibility pattern. Wraps given methods and calls them in a chain.

To make an object chainable, simply include the module and call the class method chain_method for each method that should be chained.

Example is a simplified version of the Wikipedia one (en.wikipedia.org/wiki/Chain-of-responsibility_pattern)

 class Logger
   include Juicer::Chainable

   ERR = 3
   NOTICE = 5
   DEBUG = 7

   def initialize(level)
     @level = level
   end

   def log(str, level)
     if level <= @level
       write str
     else
       abort_chain
     end
   end

   def write(str)
     puts str
   end

   chain_method :message
 end

 class EmailLogger < Logger
   def write(str)
     p "Logging by email"
     # ...
   end
 end

 logger = Logger.new(Logger::NOTICE)
 logger.next_in_chain = EmailLogger.new(Logger::ERR)

 logger.log("Some message", Logger::DEBUG) # Ignored
 logger.log("A warning", Logger::NOTICE)   # Logged to console
 logger.log("An error", Logger::ERR)       # Logged to console and email