Struct CallbackCtx 

pub struct CallbackCtx<'a> { /* private fields */ }

Context handed to an executable component callback body (W.5.1).

Carries the triggering payload (raw CDR — empty for timers) plus the publisher resolver, so a body can read its message and publish immediately. Service / action-result callbacks additionally carry a ReplySink the body fills via reply; action goal / cancel callbacks carry a DecisionSink the body fills via set_goal_response / set_cancel_response (W.5.3).

Implementations

impl<'a> CallbackCtx<'a>

pub fn new(payload: &'a [u8], publishers: &'a dyn PublisherResolver) -> Self

Build a callback context with no reply sink (timer / subscription). payload is the entity’s raw CDR (empty slice for timers).

pub fn with_reply( payload: &'a [u8], publishers: &'a dyn PublisherResolver, reply_buf: &'a mut [u8], reply_written: &'a mut usize, ) -> Self

Build a callback context with a reply sink (service / action-result; W.5.3). The body fills reply_buf via reply; the generated trampoline reads *reply_written back as the response length.

pub fn with_goal_decision( payload: &'a [u8], publishers: &'a dyn PublisherResolver, out: &'a mut GoalResponse, ) -> Self

Build a context for an action goal callback (W.5.3): the body decides accept/reject via set_goal_response; the generated trampoline returns *out. payload is the goal CDR.

pub fn with_cancel_decision( payload: &'a [u8], publishers: &'a dyn PublisherResolver, out: &'a mut CancelResponse, ) -> Self

Build a context for an action cancel callback (W.5.3): the body decides accept/reject via set_cancel_response.

pub fn set_goal_response(&mut self, response: GoalResponse) -> NodeResult<()>

Set the action goal-callback’s accept/reject decision (W.5.3). Err when the callback is not a goal decision.

pub fn set_cancel_response( &mut self, response: CancelResponse, ) -> NodeResult<()>

Set the action cancel-callback’s accept/reject decision (W.5.3). Err when the callback is not a cancel decision.

pub fn reply_raw(&mut self, data: &[u8]) -> NodeResult<()>

Write the service / action reply as raw CDR bytes (W.5.3). Err when the callback has no reply sink (timer / subscription) or the reply exceeds the lent buffer.

pub fn reply<M: RosMessage, const N: usize>( &mut self, msg: &M, ) -> NodeResult<()>

Serialize msg and write it as the service / action reply (W.5.3).

pub fn payload(&self) -> &[u8]

Raw CDR payload of the triggering message / request. Empty for timers.

pub fn message<M: RosMessage>(&self) -> NodeResult<M>

Deserialize the triggering payload as M (subscription / service-request bodies). Err if the payload is malformed for M.

pub fn publish_to_topic<M: RosMessage, const N: usize>( &self, topic: &str, msg: &M, ) -> NodeResult<()>

Serialize msg and publish through the entity synthesized from topic.

This pairs with DeclaredNode::create_publisher_for_topic, allowing simple callback bodies to use the ROS topic literal instead of restating an unrelated stable entity ID.