Event Broker

In process event brokers based on javascript generator

The available brokers are:

• AsyncEventBroker

  An asynchronous event broker that support a single event handler.

• EventBroker

  Synchronous event broker that support a single event handlers

• AsyncEventBrokerML

  An asynchronous event broker that supports multiple event handlers.

• AsyncEventBrokerTopicsML

  An asynchronous event broker that supports multiple topics with multiple event handlers.

AsyncEventBroker Usage

Define Events' type

const replySymbol = Symbol("reply"); 

type ListenEvent = { data: string, [replySymbol]?: boolean  }
type ReplyEvent = { result: string }

Create an instance

const broker = new AsyncEventBroker<ListenEvent, ReplyEvent>()

Start broker

const listenerId = await broker.on( async ( ev:ListenEvent ) => {

    // handle event
    const result = await doSomething( ev.data )

    if( !!ev[replySymbol] ) { // if reply is required
        return { result } ; // this will be replyed to sender
    }
})

Note:

listenerId must be stored because it is need for eventually stop listening event. This is because: Only who start broker will be able to stop it

Send event to broker

await broker.emit( { data: "message1" } )

Send event to broker and wait reply

const reply = await broker.emitWithReply( { data: "message_with_reply", [replySymbol]: true  } )
// reply = { result: "....." }

Stop broker

try {
    await broker.off( startId )
}
catch( e ) {
    // startId is not valid !!!
}

Other Examples

Other usage examples could be found in test folder