def subscriptions(self):
"""
A tuple containing the topics that the client is currently subscribed to
See :func:`subscribe` for more information on adding subscriptions
"""
logger.debug("%s(): Waiting for Subscriptions lock...",
DxlUtils.func_name())
self._subscriptions_lock.acquire()
try:
return tuple(self._subscriptions)
finally:
logger.debug("%s(): Releasing Subscriptions lock.",
DxlUtils.func_name())
self._subscriptions_lock.release()
def unsubscribe(self, topic):
"""
Unsubscribes from the specified topic on the DXL fabric.
See the :func:`subscribe` method for more information on subscriptions.
:param topic: The topic to unsubscribe from
"""
logger.debug("%s(): Waiting for Subscriptions lock...",
DxlUtils.func_name())
self._subscriptions_lock.acquire()
try:
if topic in self._subscriptions:
if self.connected:
self._client.unsubscribe(topic)
finally:
self._subscriptions.remove(topic)
logger.debug("%s(): Releasing Subscriptions lock.",
DxlUtils.func_name())
self._subscriptions_lock.release()
def subscribe(self, topic):
"""
Subscribes to the specified topic on the DXL fabric. This method is typically used in
conjunction with the registration of :class:`dxlclient.callbacks.EventCallback` instances
via the :func:`add_event_callback` method.
The following is a simple example of using this:
.. code-block:: python
from dxlclient.callbacks import EventCallback
class MyEventCallback(EventCallback):
def on_event(self, event):
print "Received event! " + event.source_client_id
dxl_client.add_event_callback("/testeventtopic", MyEventCallback(), False)
dxl_client.subscribe("/testeventtopic")
**NOTE:** By default when registering an event callback the client will automatically subscribe to the topic.
In this example the :func:`dxlclient.client.DxlClient.add_event_callback` method is invoked with the
``subscribe_to_topic`` parameter set to ``False`` preventing the automatic subscription.
:param topic: The topic to subscribe to
"""
logger.debug("%s(): Waiting for Subscriptions lock...",
DxlUtils.func_name())
self._subscriptions_lock.acquire()
try:
if topic not in self._subscriptions:
self._subscriptions.add(topic)
if self.connected:
self._client.subscribe(topic)
except Exception as ex:
logger.error("Error during subscribe: %s", ex.message)
logger.debug(traceback.format_exc())
raise DxlException("Error during subscribe" + str(ex))
finally:
logger.debug("%s(): Releasing Subscriptions lock.",
DxlUtils.func_name())
self._subscriptions_lock.release()
def unsubscribe(self, topic):
"""
Unsubscribes from the specified topic on the DXL fabric.
See the :func:`subscribe` method for more information on subscriptions.
:param topic: The topic to unsubscribe from
"""
logger.debug("%s(): Waiting for Subscriptions lock...",
DxlUtils.func_name())
self._subscriptions_lock.acquire()
try:
if topic in self._subscriptions:
if self.connected:
self._client.unsubscribe(topic)
except Exception as ex:
logger.error("Error during unsubscribe: %s", ex.message)
logger.debug(traceback.format_exc())
raise DxlException("Error during unsubscribe")
finally:
self._subscriptions.remove(topic)
logger.debug("%s(): Releasing Subscriptions lock.",
DxlUtils.func_name())
self._subscriptions_lock.release()