def subscribe_locally(self, messagetype, instance, callback):
MessageBus.subscribe_locally(self, messagetype, instance, callback)
for message in self.message_queue[messagetype]:
if (message, message.sender) == (messagetype, instance):
self.broadcast(message)
self.message_queue[messagetype].remove(message)
def subscribe_locally(self, messagetype, instance, callback): MessageBus.subscribe_locally(self, messagetype, instance, callback) for message in self.message_queue[messagetype]: if (message, message.sender) == (messagetype, instance): self.broadcast(message) self.message_queue[messagetype].remove(message)
def discard(cls, callback, sender=None):
"""Similar to `Message.unsubscribe`, but does not raise an error if the
callback has not been registered before.
"""
if sender:
MessageBus().discard_locally(cls, sender, callback)
else:
MessageBus().discard_globally(cls, callback)
def broadcast(self, message): messagetype = message.__class__ pair = (messagetype, message.sender) # check if the message will go anywhere, if not, then queue it if not len(self.global_receivers[messagetype]) and not len(self.local_receivers[pair]): self.message_queue[messagetype].append(message) else: MessageBus.broadcast(self, message)
def broadcast(self, message):
messagetype = message.__class__
pair = (messagetype, message.sender)
# check if the message will go anywhere, if not, then queue it
if not len(self.global_receivers[messagetype]) and not len(
self.local_receivers[pair]):
self.message_queue[messagetype].append(message)
else:
MessageBus.broadcast(self, message)
def subscribe(cls, callback, sender=None):
"""Register a callback to be called whenever a message of this type is send.
callback - Callable that receives an instance of a message as only argument.
sender - If specified, the callback receives only messages that originated
from sender. By default, all messages are received.
Example:
>>> def cb(msg):
... print 'Received', msg
>>> MessageClass.subscribe(cb) # Global
>>> MessageClass.subscribe(cb, sender=foo) # Specific sender
"""
if sender:
MessageBus().subscribe_locally(cls, sender, callback)
else:
MessageBus().subscribe_globally(cls, callback)
def unsubscribe(cls, callback, sender=None):
"""Stop your subscription of this message type for the specified callback.
callback - Callable that receives an instance of a message as only argument.
The same you've been using with `Message.subscribe`.
sender - If specified, the subscription will only be stopped for messages
from this sender. By default, all subscriptions are ended.
Note: There has to be a subscription, otherwise an error will be raised.
Example:
>>> MessageClass.subscribe(cb)
>>> MessageClass.broadcast('sender')
message received
>>> MessageClass.unsubscribe(cb)
>>> MessageClass.broadcast('sender')
"""
if sender:
MessageBus().unsubscribe_locally(cls, sender, callback)
else:
MessageBus().unsubscribe_globally(cls, callback)
def broadcast(cls, *args):
"""Send a message that is initialized with `args`.
The first argument is always a sender, the number of arguments has to be
N + 1, with N being the number of arguments defined on the message class.
Example:
>>> class Foo(Message):
... arguments = ('a', 'b', )
>>> Foo.broadcast('sender', 1, 2)
"""
MessageBus().broadcast(cls(*args))
def subscribe_globally(self, messagetype, callback):
MessageBus.subscribe_globally(self, messagetype, callback)
while len(self.message_queue[messagetype]):
self.broadcast(self.message_queue[messagetype].popleft())
def __init__(self):
MessageBus.__init__(self)
# Queue up messages if there is no registered subscriber
self.message_queue = defaultdict(deque)
def discard(cls, callback):
"""Similar to `Message.unsubscribe`, but does not raise an error if the
callback has not been registered before.
"""
MessageBus().discard_globally(cls, callback)
def subscribe_globally(self, messagetype, callback): MessageBus.subscribe_globally(self, messagetype, callback) while self.message_queue[messagetype]: self.broadcast(self.message_queue[messagetype].popleft())
def __init__(self): MessageBus.__init__(self) # Queue up messages if there is no registered subscriber self.message_queue = defaultdict(deque)
