Services¶

Client¶

class rclpy.client.Client(context, client_handle, srv_type, srv_name, qos_profile, callback_group)¶

Create a container for a ROS service client.

Warning

Users should not create a service client with this constuctor, instead they should call Node.create_client().

Parameters:

context (Context) – The context associated with the service client.
client_handle – Handle wrapping the underlying rcl_client_t object.
srv_type (~SrvType) – The service type.
srv_name (str) – The name of the service.
qos_profile (QoSProfile) – The quality of service profile to apply the service client.
callback_group (CallbackGroup) – The callback group for the service client. If None, then the nodes default callback group is used.

call(request)¶

Make a service request and wait for the result.

Do not call this method in a callback or a deadlock may occur.

Parameters:	request (~SrvTypeRequest) – The service request.
Return type:	~SrvTypeResponse
Returns:	The service response.
Raises:	TypeError if the type of the passed request isn’t an instance of the Request type of the provided service when the client was constructed.

call_async(request)¶

Make a service request and asyncronously get the result.

Parameters:	request (~SrvTypeRequest) – The service request.
Return type:	`Future`
Returns:	A future that completes when the request does.
Raises:	TypeError if the type of the passed request isn’t an instance of the Request type of the provided service when the client was constructed.

remove_pending_request(future)¶

Remove a future from the list of pending requests.

This prevents a future from receiving a response and executing its done callbacks.

Parameters:	future (`Future`) – A future returned from `call_async()`
Return type:	`None`

service_is_ready()¶

Check if there is a service server ready.

Return type:	`bool`
Returns:	`True` if a server is ready, `False` otherwise.

wait_for_service(timeout_sec=None)¶

Wait for a service server to become ready.

Returns as soon as a server becomes ready or if the timeout expires.

Parameters:	timeout_sec (`Optional`[`float`]) – Seconds to wait. If `None`, then wait forever.
Return type:	`bool`
Returns:	`True` if server became ready while waiting or `False` on a timeout.

class rclpy.service.Service(service_handle, srv_type, srv_name, callback, callback_group, qos_profile)¶

Create a container for a ROS service server.

Warning

Users should not create a service server with this constuctor, instead they should call Node.create_service().

Parameters:

context – The context associated with the service server.
service_handle – Capsule pointing to the underlying rcl_service_t object.
srv_type (~SrvType) – The service type.
srv_name (str) – The name of the service.
callback_group (CallbackGroup) – The callback group for the service server. If None, then the nodes default callback group is used.
qos_profile (QoSProfile) – The quality of service profile to apply the service server.

send_response(response, header)¶

Send a service response.

Parameters:	response (~SrvTypeResponse) – The service response. header – Capsule pointing to the service header from the original request.
Raises:	TypeError if the type of the passed response isn’t an instance of the Response type of the provided service when the service was constructed.
Return type:	`None`