Module | Test::Unit::Util::Observable |
In: |
lib/test/unit/util/observable.rb
|
This is a utility class that allows anything mixing it in to notify a set of listeners about interesting events.
NOTHING | = | "NOTHING/#{__id__}" | We use this for defaults since nil might mean something |
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 31: def add_listener(channel_name, listener_key=NOTHING, &listener) # :yields: value 32: unless(block_given?) 33: raise ArgumentError.new("No callback was passed as a listener") 34: end 35: 36: key = listener_key 37: if (listener_key == NOTHING) 38: listener_key = listener 39: key = ProcWrapper.new(listener) 40: end 41: 42: channels[channel_name] ||= {} 43: channels[channel_name][key] = listener 44: return listener_key 45: 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 lib/test/unit/util/observable.rb, line 74 74: def notify_listeners(channel_name, *arguments) 75: channel = channels[channel_name] 76: return 0 unless (channel) 77: listeners = channel.values 78: listeners.each { |listener| listener.call(*arguments) } 79: return listeners.size 80: 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 lib/test/unit/util/observable.rb, line 51 51: def remove_listener(channel_name, listener_key) 52: channel = channels[channel_name] 53: return nil unless (channel) 54: key = listener_key 55: if (listener_key.instance_of?(Proc)) 56: key = ProcWrapper.new(listener_key) 57: end 58: if (channel.has_key?(key)) 59: return channel.delete(key) 60: end 61: return nil 62: end