yasmin_ros.service_state.ServiceState Class Reference

Inheritance diagram for yasmin_ros.service_state.ServiceState:

Collaboration diagram for yasmin_ros.service_state.ServiceState:

Public Member Functions
None	__init__ (self, Type srv_type, str srv_name, Callable create_request_handler, Set[str] outcomes=None, Callable response_handler=None, CallbackGroup callback_group=None, Node node=None, float wait_timeout=None, float response_timeout=None, int maximum_retry=3)
str	execute (self, Blackboard blackboard)
None	response_callback (self, Future future)

Public Attributes
	response_callback = self._service_client.call_async(request)

Protected Attributes
Callable[[Blackboard], Any]	_create_request_handler = create_request_handler
	Function to create service requests.
Callable[[Blackboard, Any], str]	_response_handler = response_handler
	Function to handle service responses.
float	_wait_timeout = wait_timeout
	Maximum wait time for service availability.
float	_response_timeout = response_timeout
	Timeout for the service response.
Node	_node = node
	The ROS 2 node used to communicate with the service.
str	_srv_name = srv_name
	Name of the service.
Client	_service_client
	Shared pointer to the service client.
Any	_response = None
	The response received from the service.
int	_maximum_retry = maximum_retry
	Maximum number of retries.
Event	_response_received_event = Event()
	Event to signal when the service response is received.

Detailed Description

A state class that interacts with a ROS 2 service.

This class manages communication with a specified ROS 2 service,
allowing it to send requests and handle responses. It extends
the base State class.

Attributes:
    _node (Node): The ROS 2 node used to communicate with the service.
    _srv_name (str): The name of the service to call.
    _service_client (Client): The client used to call the service.
    _create_request_handler (Callable[[Blackboard], Any]): Function to create service requests.
    _response (Any): The response received from the service.
    _response_handler (Callable[[Blackboard, Any], str]): Function to handle service responses.
    _wait_timeout (float): Maximum wait time for service availability.
    _response_timeout (float): Timeout for the service response.
    _maximum_retry (int): Maximum number of retries.
    _response_received_event (Event): Event to signal when the service response is received.

Constructor & Destructor Documentation

__init__()

None yasmin_ros.service_state.ServiceState.__init__	(		self,
		Type	srv_type,
		str	srv_name,
		Callable	create_request_handler,
		Set[str]	outcomes = None,
		Callable	response_handler = None,
		CallbackGroup	callback_group = None,
		Node	node = None,
		float	wait_timeout = None,
		float	response_timeout = None,
		int	maximum_retry = 3 )

Initializes the ServiceState with the provided parameters.

Args:
    srv_type (Type): The type of the service.
    srv_name (str): The name of the service to call.
    create_request_handler (Callable[[Blackboard], Any]): Function to create a service request.
    outcomes (Set[str], optional): A set of possible outcomes for this state.
    response_handler (Callable[[Blackboard, Any], str], optional): Function to handle the service response.
    callback_group (CallbackGroup, optional): The callback group for the service client.
    node (Node, optional): A ROS 2 node instance; if None, a default instance is used.
    wait_timeout (float, optional): Maximum time to wait for the service to become available. Default is None (wait indefinitely).
    response_timeout (float, optional): Maximum time to wait for the service response. Default is None (wait indefinitely).
    maximum_retry (int, optional): Maximum retries of the service if it returns timeout. Default is 3.

Raises:
    ValueError: If the create_request_handler is not provided.

Member Function Documentation

execute()

str yasmin_ros.service_state.ServiceState.execute	(		self,
		Blackboard	blackboard )

Execute the service call and handle the response.

This method creates a request based on the blackboard data, waits for the
service to become available, sends the request asynchronously, and waits for
the response using a threading Event.

Args:
    blackboard (Blackboard): A shared pointer to the blackboard containing data for
        request creation.

Returns:
    str: The outcome of the service call, which can be SUCCEED, ABORT, or TIMEOUT.

response_callback()

None yasmin_ros.service_state.ServiceState.response_callback	(		self,
		Future	future )

Callback function to process the service response.

This method is called when the service response is received. It stores
the response and signals the waiting thread by setting the event.

Args:
    future (Future): The future object containing the service response.

Member Data Documentation

_create_request_handler

Callable[[Blackboard], Any] yasmin_ros.service_state.ServiceState._create_request_handler = create_request_handler

protected

Function to create service requests.

_maximum_retry

int yasmin_ros.service_state.ServiceState._maximum_retry = maximum_retry

protected

Maximum number of retries.

_node

Node yasmin_ros.service_state.ServiceState._node = node

protected

The ROS 2 node used to communicate with the service.

_response

Any yasmin_ros.service_state.ServiceState._response = None

protected

The response received from the service.

_response_handler

Callable[[Blackboard, Any], str] yasmin_ros.service_state.ServiceState._response_handler = response_handler

protected

Function to handle service responses.

_response_received_event

Event yasmin_ros.service_state.ServiceState._response_received_event = Event()

protected

Event to signal when the service response is received.

_response_timeout

yasmin_ros.service_state.ServiceState._response_timeout = response_timeout

protected

Timeout for the service response.

_service_client

Client yasmin_ros.service_state.ServiceState._service_client

protected

Initial value:

=  ROSClientsCache.get_or_create_service_client(
            self._node,
            srv_type,
            srv_name,
            callback_group=callback_group,
        )

Shared pointer to the service client.

_srv_name

str yasmin_ros.service_state.ServiceState._srv_name = srv_name

protected

Name of the service.

_wait_timeout

float yasmin_ros.service_state.ServiceState._wait_timeout = wait_timeout

protected

Maximum wait time for service availability.

response_callback

yasmin_ros.service_state.ServiceState.response_callback = self._service_client.call_async(request)

---

The documentation for this class was generated from the following file:

• yasmin_ros/yasmin_ros/service_state.py