Test::Unit::Util::Observable

This is a utility class that allows anything mixing it in to notify a set of listeners about interesting events.

Constants

NOTHING: We use this for defaults since nil might mean something

Public Instance Methods

add_listener(channel_name, listener_key=NOTHING) click to toggle source

Adds the passed proc as a listener on the channel indicated by channel_name. listener_key is used to remove the listener later; if none is specified, the proc itself is used.

Whatever is used as the listener_key is returned, making it very easy to use the proc itself as the listener_key:

 listener = add_listener("Channel") { ... }
 remove_listener("Channel", listener)

# File lib/test/unit/util/observable.rb, line 31
        def add_listener(channel_name, listener_key=NOTHING, &listener) # :yields: value
          unless(block_given?)
            raise ArgumentError.new("No callback was passed as a listener")
          end
      
          key = listener_key
          if (listener_key == NOTHING)
            listener_key = listener
            key = ProcWrapper.new(listener)
          end
      
          channels[channel_name] ||= {}
          channels[channel_name][key] = listener
          return listener_key
        end

notify_listeners(channel_name, *arguments) click to toggle source

Calls all the procs registered on the channel indicated by channel_name. If value is specified, it is passed in to the procs, otherwise they are called with no arguments.

# File lib/test/unit/util/observable.rb, line 74
        def notify_listeners(channel_name, *arguments)
          channel = channels[channel_name]
          return 0 unless (channel)
          listeners = channel.values
          listeners.each { |listener| listener.call(*arguments) }
          return listeners.size
        end

remove_listener(channel_name, listener_key) click to toggle source

Removes the listener indicated by listener_key from the channel indicated by channel_name. Returns the registered proc, or nil if none was found.

# File lib/test/unit/util/observable.rb, line 51
        def remove_listener(channel_name, listener_key)
          channel = channels[channel_name]
          return nil unless (channel)
          key = listener_key
          if (listener_key.instance_of?(Proc))
            key = ProcWrapper.new(listener_key)
          end
          if (channel.has_key?(key))
            return channel.delete(key)
          end
          return nil
        end

Private Instance Methods

channels() click to toggle source

(Not documented)

# File lib/test/unit/util/observable.rb, line 83
        def channels
          @channels ||= {}
          return @channels
        end

In Files

Methods

Files

Class Index

Test::Unit::Util::Observable

Constants

Public Instance Methods

Private Instance Methods