blob: 24d4c0cedfb7839629bd6c4b99a8963b223e07c5 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
|
module Callback
class CallbackContainer
def initialize
@callback_registry = Hash.new do |hash, key|
hash[key] = Array.new
end
end
# Defines the callback with the key in this container.
def define(key, callback_proc=nil, &callback_block)
callback = extract_callback(callback_block, callback_proc) do
raise "You must define the callback that accepts the call method."
end
@callback_registry[key] << callback
callback
end
# Undefines the callback with the key in this container.
def undefine(key, callback_proc)
callback = extract_callback(callback_proc) do
raise "You may only undefine callbacks that use the call method."
end
@callback_registry[key].delete callback
callback
end
# Notifies the callbacks for the key. Arguments may be passed.
# An error handler may be passed in as a block. If there is an error, the block is called with
# error object as an argument.
# An array of the return values of the callbacks is returned.
def notify(key, *args, &error_handler)
@callback_registry[key].collect do |callback|
begin
callback.call(*args)
rescue Exception => e
yield(e) if error_handler
end
end
end
# Clears all of the callbacks in this container.
def clear
@callback_registry.clear
end
protected
def extract_callback(first_choice_callback, second_choice_callback = nil)
callback = nil
if first_choice_callback
callback = first_choice_callback
elsif second_choice_callback
callback = second_choice_callback
end
unless callback.respond_to? :call
yield
end
return callback
end
end
end
|
