Module: Test::Unit::Util::Observable
Relationships & Source Files | |
Extension / Inclusion / Inheritance Descendants | |
Included In:
| |
Defined in: | lib/test/unit/util/observable.rb |
Overview
This is a utility class that allows anything mixing it in to notify a set of listeners about interesting events.
Constant Summary
-
NOTHING =
We use this for defaults since nil might mean something
"NOTHING/#{__id__}"
Instance Method Summary
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#add_listener(channel_name, listener_key = NOTHING, &listener)
Adds the passed proc as a listener on the channel indicated by channel_name.
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#notify_listeners(channel_name, *arguments)
Calls all the procs registered on the channel indicated by channel_name.
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#remove_listener(channel_name, listener_key)
Removes the listener indicated by listener_key from the channel indicated by channel_name.
- #channels private
Instance Method Details
#add_listener(channel_name, listener_key = NOTHING, &listener)
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
#channels (private)
[ GitHub ]# File 'lib/test/unit/util/observable.rb', line 83
def channels @channels ||= {} return @channels end
#notify_listeners(channel_name, *arguments)
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)
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