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Diffstat (limited to 'creactistore/_templates/lib/rdflib/events.py')
-rw-r--r-- | creactistore/_templates/lib/rdflib/events.py | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/creactistore/_templates/lib/rdflib/events.py b/creactistore/_templates/lib/rdflib/events.py new file mode 100644 index 0000000..4280018 --- /dev/null +++ b/creactistore/_templates/lib/rdflib/events.py @@ -0,0 +1,92 @@ + +__doc__ = """ +Dirt Simple Events + +A Dispatcher (or a subclass of Dispatcher) stores event handlers that +are 'fired' simple event objects when interesting things happen. + +Create a dispatcher: + + >>> d = Dispatcher() + +Now create a handler for the event and subscribe it to the dispatcher +to handle Event events. A handler is a simple function or method that +accepts the event as an argument: + + >>> def handler1(event): print(repr(event)) + >>> d.subscribe(Event, handler1) + +Now dispatch a new event into the dispatcher, and see handler1 get +fired: + + >>> d.dispatch(Event(foo='bar', data='yours', used_by='the event handlers')) + <rdflib.events.Event ['data', 'foo', 'used_by']> +""" + +__all__ = ['Event', 'Dispatcher'] + +class Event(object): + """ + An event is a container for attributes. The source of an event + creates this object, or a subclass, gives it any kind of data that + the events handlers need to handle the event, and then calls + notify(event). + + The target of an event registers a function to handle the event it + is interested with subscribe(). When a sources calls + notify(event), each subscriber to that even will be called i no + particular order. + """ + + def __init__(self, **kw): + self.__dict__.update(kw) + + def __repr__(self): + attrs = self.__dict__.keys() + attrs.sort() + return '<rdflib.events.Event %s>' % ([a for a in attrs],) + + +class Dispatcher(object): + """ + An object that can dispatch events to a privately managed group of + subscribers. + """ + + _dispatch_map = None + + def set_map(self, amap): + self._dispatch_map = amap + + def get_map(self): + return self._dispatch_map + + def subscribe(self, event_type, handler): + """ Subscribe the given handler to an event_type. Handlers + are called in the order they are subscribed. + """ + if self._dispatch_map is None: + self.set_map({}) + lst = self._dispatch_map.get(event_type, None) + if lst is None: + lst = [handler] + else: + lst.append(handler) + self._dispatch_map[event_type] = lst + + def dispatch(self, event): + """ Dispatch the given event to the subscribed handlers for + the event's type""" + if self._dispatch_map is not None: + lst = self._dispatch_map.get(type(event), None) + if lst is None: + raise ValueError("unknown event type: %s" % type(event)) + for l in lst: + l(event) + +def test(): + import doctest + doctest.testmod() + +if __name__ == '__main__': + test() |