module 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
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 test-unit-3.6.1/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
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 test-unit-3.6.1/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
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 test-unit-3.6.1/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
# File test-unit-3.6.1/lib/test/unit/util/observable.rb, line 83 def channels @channels ||= {} return @channels end