Requirements

• Python >= 3.4

Usage

Example:

import logging
from signaller import Signal, autoconnect

# Enable verbose logging
logging.basicConfig(level=logging.DEBUG)

# Creating signals (you can set signal name, but it is not required,
# signals can be anonymous):
sig_test = Signal('sig_test')

# Connecting signals to slots (uses weak references by default,
# but you can force strong references by specifying weak=False):
def slot(arg):
    print('slot:', arg)

sig_test.connect(slot)
sig_test.connect(lambda arg: print('slot_lambda:', arg), weak=False)

# You can also use decorators for connecting signals to slots:
@sig_test.connect
def slot2(arg):
    print('slot2:', arg)

# And keyword arguments can be specified when using decorators too:
@sig_test.connect(force_async=True)
def slot3(arg):
    print('slot3:', arg)

# You can also use decorators on methods, then signals will be connected to instance
# methods automatically whenever new instance is created. But you must decorate class
# with @autoconnect decorator for autoconnection to work. Class methods and
# static methods are not supported.
@autoconnect
class Cls:
    @sig_test.connect
    def slot4(self, arg):
        print('slot4:', arg)

obj = Cls()

# Slots are automatically disconnected from signals
# when using weak references:
del slot

# Or you can disconnect slots manually:
sig_test.disconnect(slot2)

# Emitting signals (you can send both positional and keyword
# arguments to connected slots):
sig_test.emit('Hello world!')

Output:

INFO:signaller:Connecting signal <Signal 'sig_test' at 0x7f3c468bfc50> to slot <function slot at 0x7f3c46cc6f28>
INFO:signaller:Connecting signal <Signal 'sig_test' at 0x7f3c468bfc50> to slot <function <lambda> at 0x7f3c468c97b8>
INFO:signaller:Connecting signal <Signal 'sig_test' at 0x7f3c468bfc50> to slot <function slot2 at 0x7f3c43c9e400>
INFO:signaller:Connecting signal <Signal 'sig_test' at 0x7f3c468bfc50> to slot <function slot3 at 0x7f3c43c9e598>
DEBUG:signaller:Marking instance method <function Cls.slot4 at 0x7f3c43c9e6a8> for autoconnect to signal <Signal 'sig_test' at 0x7f3c468bfc50>
INFO:signaller:Connecting signal <Signal 'sig_test' at 0x7f3c468bfc50> to slot <bound method Cls.slot4 of <__main__.Cls object at 0x7f3c43f11d30>>
DEBUG:signaller:Object <function slot at 0x7f3c46cc6f28> has been deleted
INFO:signaller:Disconnecting slot <Reference (weak) to <function slot at 0x7f3c46cc6f28> (dead)> from signal <Signal 'sig_test' at 0x7f3c468bfc50>
INFO:signaller:Disconnecting slot <function slot2 at 0x7f3c43c9e400> from signal <Signal 'sig_test' at 0x7f3c468bfc50>
INFO:signaller:Emitting signal <Signal 'sig_test' at 0x7f3c468bfc50>
DEBUG:signaller:Calling slot <Reference (weak) to <function slot3 at 0x7f3c43c9e598>> asynchronously (in executor <concurrent.futures.thread.ThreadPoolExecutor object at 0x7f3c468bff28>)
slot3: Hello world!
DEBUG:signaller:Calling slot <Reference (strong) to <function <lambda> at 0x7f3c468c97b8>>
slot_lambda: Hello world!
DEBUG:signaller:Calling slot <Reference (weak) to <bound method Cls.slot4 of <__main__.Cls object at 0x7f3c43f11d30>>>
slot4: Hello world!