Send MessageBus Event

Pushes a named event to the Application Message Bus. The payload of the event is constructed from any dynamic input attributes that have been added to this node and consists of a dictionary whose key is the name of the attribute, with the ‘inputs:’ prefix stripped from it, with a value equal to the raw pointer to the attribute’s data in Fabric. If the attribute has a type that is not able to be converted to this form then a warning is posted for the node but the execution continues.

The event can be handled by any message bus listener, or with a corresponding OnMessageBusEvent node.

Data from dynamic input attributes will be copied into the event payload, with keys that match the attribute name. Here’s an example of handling the event in Python. In this example the sending node has an input “inputs:arg1”:

import carb.events
import omni.kit.app

def on_event(event: carb.events.IEvent):
    data = event.payload["arg1"]
    print(f"got data = {data}")

msg = carb.events.type_from_string("my_event_name")
message_bus = omni.kit.app.get_app().get_message_bus_event_stream()
sub = message_bus.create_subscription_to_pop_by_type(msg, on_event)

Installation

To use this node enable omni.graph.action_nodes_core in the Extension Manager.

Inputs

Name	Type	Descripton	Default
Event Name (inputs:eventName)	token	The name of the custom event to be sent.
	Metadata	literalOnly = 1
Exec In (inputs:execIn)	execution	Signal to the graph that this node is ready to be executed.	None

Outputs

Name	Type	Descripton	Default
Exec Out (outputs:execOut)	execution	Signal to the graph that execution can continue downstream.	None

Metadata

Name	Value
Unique ID	omni.graph.action.SendMessageBusEvent
Version	1
Extension	omni.graph.action_nodes_core
Has State?	False
Implementation Language	C++
Default Memory Type	cpu
Generated Code Exclusions	tests
uiName	Send MessageBus Event
Categories	graph:action,event
Generated Class Name	OgnSendMessageBusEventDatabase
Python Module	omni.graph.action_nodes_core