def destroy_subscription(self, subscription: Subscription) -> bool:
"""
Destroy a subscription created by the node.
:return: ``True`` if succesful, ``False`` otherwise.
"""
if subscription in self.__subscriptions:
self.__subscriptions.remove(subscription)
try:
subscription.destroy()
except InvalidHandle:
return False
return True
return False
def create_subscription(self,
msg_type,
topic,
callback,
*,
qos_profile=qos_profile_default,
callback_group=None):
if callback_group is None:
callback_group = self._default_callback_group
# this line imports the typesupport for the message module if not already done
check_for_type_support(msg_type)
failed = False
try:
[subscription_handle,
subscription_pointer] = _rclpy.rclpy_create_subscription(
self.handle, msg_type, topic, qos_profile.get_c_qos_profile())
except ValueError:
failed = True
if failed:
self._validate_topic_or_service_name(topic)
subscription = Subscription(subscription_handle, subscription_pointer,
msg_type, topic, callback, callback_group,
qos_profile, self.handle)
self.subscriptions.append(subscription)
callback_group.add_entity(subscription)
return subscription
def create_subscription(self, msg_type, topic, callback, qos_profile=qos_profile_default):
# this line imports the typesupport for the message module if not already done
if msg_type.__class__._TYPE_SUPPORT is None:
msg_type.__class__.__import_type_support__()
if msg_type.__class__._TYPE_SUPPORT is None:
raise NoTypeSupportImportedException
[subscription_handle, subscription_pointer] = _rclpy.rclpy_create_subscription(
self.handle, msg_type, topic, qos_profile.get_c_qos_profile())
subscription = Subscription(
subscription_handle, subscription_pointer, msg_type,
topic, callback, qos_profile, self.handle)
self.subscriptions.append(subscription)
return subscription
def create_subscription(self,
msg_type,
topic: str,
callback: Callable[[MsgType], None],
*,
qos_profile: QoSProfile = qos_profile_default,
callback_group: CallbackGroup = None,
raw: bool = False) -> Subscription:
"""
Create a new subscription.
:param msg_type: The type of ROS messages the subscription will subscribe to.
:param topic: The name of the topic the subscription will subscribe to.
:param callback: A user-defined callback function that is called when a message is
received by the subscription.
:param qos_profile: The quality of service profile to apply to the subscription.
:param callback_group: The callback group for the subscription. If ``None``, then the
nodes default callback group is used.
:param raw: If ``True``, then received messages will be stored in raw binary
representation.
"""
if callback_group is None:
callback_group = self.default_callback_group
# this line imports the typesupport for the message module if not already done
check_for_type_support(msg_type)
failed = False
try:
with self.handle as capsule:
subscription_capsule = _rclpy.rclpy_create_subscription(
capsule, msg_type, topic, qos_profile.get_c_qos_profile())
except ValueError:
failed = True
if failed:
self._validate_topic_or_service_name(topic)
subscription_handle = Handle(subscription_capsule)
subscription_handle.requires(self.handle)
subscription = Subscription(subscription_handle, msg_type, topic,
callback, callback_group, qos_profile, raw)
self.__subscriptions.append(subscription)
callback_group.add_entity(subscription)
return subscription