RosActionClient¶

A ROS 2 Action Client for sending goals to an action server.

Description¶

RosActionClient allows Godot to send goals to ROS 2 action servers. It is created through RosNode.create_action_client().

Actions are designed for long-running tasks: unlike services they provide continuous feedback while the goal executes, and they can be canceled mid-flight.

Use create_goal() to build a goal message, then send_goal() to dispatch it. The returned RosGoalHandle acts as a handle for the in-flight goal: connect to its signals or await them to track acceptance, feedback and the final result.

var client = ros_node.create_action_client("fibonacci", "example_interfaces/action/Fibonacci")
if client.wait_for_server(2.0):
    var goal = client.create_goal()
    goal.order = 10
    var handle = client.send_goal(goal)
    handle.feedback.connect(func(msg): print("Partial: ", msg.sequence))
    await handle.completed
    if handle.get_status() == RosGoalHandle.STATUS_SUCCEEDED:
        print("Result: ", handle.get_result().sequence)

Methods¶

RosMsg	create_goal()
bool	is_server_ready() const
RosGoalHandle	send_goal(goal: RosMsg)
bool	wait_for_server(timeout_sec: float)
void	wait_for_server_async(timeout_sec: float)

Signals¶

server_available(available: bool) 🔗

Emitted when the action server becomes available or when an asynchronous wait times out.

Method Descriptions¶

RosMsg create_goal() 🔗

Creates and returns an empty RosMsg of the correct type for this client's action goals (e.g. the Goal part of the action definition).

bool is_server_ready() const 🔗

Returns true if an action server for this action is currently available. Unlike wait_for_server() this never blocks.

RosGoalHandle send_goal(goal: RosMsg) 🔗

Sends a goal to the action server asynchronously. Returns a RosGoalHandle that tracks the goal's lifecycle: acceptance/rejection, feedback and the final result.

bool wait_for_server(timeout_sec: float) 🔗

Blocks until the action server is available or timeout_sec is reached. Returns true if the server is available.

void wait_for_server_async(timeout_sec: float) 🔗

Asynchronously waits for the action server to become available up to timeout_sec seconds. Emits the server_available signal when the server state changes or the timeout is reached.