Source Code for Module pypat.behavioral.mediator

 1  from collections import defaultdict 
 2   
 3   
 4 -class Mediator(object): 
 5      """ 
 6      Mediator class as part of the Mediator design pattern. 
 7   
 8      - External Usage documentation: U{https://github.com/tylerlaberge/PyPatterns/wiki/Behavioral-Pattern-Usage} 
 9      - External Mediator Pattern documentation: U{https://en.wikipedia.org/wiki/Mediator_pattern} 
10      """ 
11 -    def __init__(self): 
12          """ 
13          Initialize a new Mediator instance. 
14          """ 
15          self.signals = defaultdict(list) 
16   
17 -    def signal(self, signal_name, *args, **kwargs): 
18          """ 
19          Send a signal out to all connected handlers. 
20   
21          @param signal_name: The name of the signal. 
22          @type signal_name: Str 
23          @param args: Positional arguments to send with the signal. 
24          @param kwargs: Keyword arguments to send with the signal. 
25          """ 
26          for handler in self.signals[signal_name]: 
27              handler(*args, **kwargs) 
28   
29 -    def connect(self, signal_name, receiver): 
30          """ 
31          Connect a receiver to a signal. 
32   
33          @param signal_name: The name of the signal to connect the receiver to. 
34          @type signal_name: str 
35          @param receiver: A handler to call when the signal is sent out. 
36          """ 
37          self.signals[signal_name].append(receiver) 
38   
39 -    def disconnect(self, signal_name, receiver): 
40          """ 
41          Disconnect a receiver from a signal. 
42   
43          @param signal_name: The name of the signal to disconnect the receiver from. 
44          @type signal_name: str 
45          @param receiver: The receiver to disconnect from the signal. 
46          """ 
47          try: 
48              self.signals[signal_name].remove(receiver) 
49          except ValueError: 
50              pass 
51