- _cleanupConnections(senderkey, signal)
- Delete any empty signals for senderkey. Delete senderkey if empty.
- _killBackref(receiver, senderkey)
- Do the actual removal of back reference from receiver to senderkey
- Remove all back-references to this senderkey
- _removeOldBackRefs(senderkey, signal, receiver, receivers)
- Kill old sendersBack references from receiver
This guards against multiple registration of the same
receiver for a given signal and sender leaking memory
as old back reference records build up.
Also removes old receiver instance from receivers
- Remove receiver from connections.
- Remove senderkey from connections.
- connect(receiver, signal=_Any, sender=_Any, weak=True)
- Connect receiver to sender for signal
receiver -- a callable Python object which is to receive
messages/signals/events. Receivers must be hashable
if weak is True, then receiver must be weak-referencable
(more precisely saferef.safeRef() must be able to create
a reference to the receiver).
Receivers are fairly flexible in their specification,
as the machinery in the robustApply module takes care
of most of the details regarding figuring out appropriate
subsets of the sent arguments to apply to a given
if receiver is itself a weak reference (a callable),
it will be de-referenced by the system's machinery,
so *generally* weak references are not suitable as
receivers, though some use might be found for the
facility whereby a higher-level library passes in
pre-weakrefed receiver references.
signal -- the signal to which the receiver should respond
if Any, receiver will receive any signal from the
indicated sender (which might also be Any, but is not
Otherwise must be a hashable Python object other than
None (DispatcherError raised on None).
sender -- the sender to which the receiver should respond
if Any, receiver will receive the indicated signals
from any sender.
if Anonymous, receiver will only receive indicated
signals from send/sendExact which do not specify a
sender, or specify Anonymous explicitly as the sender.
Otherwise can be any python object.
weak -- whether to use weak references to the receiver
By default, the module will attempt to use weak
references to the receiver objects. If this parameter
is false, then strong references will be used.
returns None, may raise DispatcherTypeError
- disconnect(receiver, signal=_Any, sender=_Any, weak=True)
- Disconnect receiver from sender for signal
receiver -- the registered receiver to disconnect
signal -- the registered signal to disconnect
sender -- the registered sender to disconnect
weak -- the weakref state to disconnect
disconnect reverses the process of connect,
the semantics for the individual elements are
logically equivalent to a tuple of
(receiver, signal, sender, weak) used as a key
to be deleted from the internal routing tables.
(The actual process is slightly more complex
but the semantics are basically the same).
Using disconnect is not required to cleanup
routing when an object is deleted, the framework
will remove routes for deleted objects
automatically. It's only necessary to disconnect
if you want to stop routing to a live object.
returns None, may raise DispatcherTypeError or
- getAllReceivers(sender=_Any, signal=_Any)
- Get list of all receivers from global tables
This gets all receivers which should receive
the given signal from sender, each receiver should
be produced only once by the resulting generator
- getReceivers(sender=_Any, signal=_Any)
- Get list of receivers from global tables
This utility function allows you to retrieve the
raw list of receivers from the connections table
for the given sender and signal pair.
there is no guarantee that this is the actual list
stored in the connections table, so the value
should be treated as a simple iterable/truth value
rather than, for instance a list to which you
might append new records.
Normally you would use liveReceivers( getReceivers( ...))
to retrieve the actual receiver objects as an iterable
- Filter sequence of receivers to get resolved, live receivers
This is a generator which will iterate over
the passed sequence, checking for weak references
and resolving them, then returning all live
- send(signal=_Any, sender=_Anonymous, *arguments, **named)
- Send signal from sender to all connected receivers.
signal -- (hashable) signal value, see connect for details
sender -- the sender of the signal
if Any, only receivers registered for Any will receive
if Anonymous, only receivers registered to receive
messages from Anonymous or Any will receive the message
Otherwise can be any python object (normally one
registered with a connect if you actually want
something to occur).
arguments -- positional arguments which will be passed to
*all* receivers. Note that this may raise TypeErrors
if the receivers do not allow the particular arguments.
Note also that arguments are applied before named
arguments, so they should be used with care.
named -- named arguments which will be filtered according
to the parameters of the receivers to only provide those
acceptable to the receiver.
Return a list of tuple pairs [(receiver, response), ... ]
if any receiver raises an error, the error propagates back
through send, terminating the dispatch loop, so it is quite
possible to not have all receivers called if a raises an
- sendExact(signal=_Any, sender=_Anonymous, *arguments, **named)
- Send signal only to those receivers registered for exact message
sendExact allows for avoiding Any/Anonymous registered
handlers, sending only to those receivers explicitly
registered for a particular signal on a particular