How to send events in Hyperledger Composer

Question

I know that in Chaincode, an event can be sent using the following command:

stub.SetEvent("<event name>", "<payload>")

How do I send a similar event in Fabric Composer? And how do I listen to this event in a Node.js application so that my UI can notify the user if a particular event happened already?

Answer 1

You define the event in your .cto file like this:

event BasicEvent {
}

And emit the event from logic.js as given below:

// emit BasicEvent
var factory = getFactory();
var basicEvent = factory.newEvent('<your namespace>', 'BasicEvent');
emit(basicEvent);

You can look up the same in the source here: https://hyperledger.github.io/composer/business-network/publishing-events.html