IPSME/npm-msgenv-broadcastchannel

npm-msgenv-broadcastchannel

This library contains the wrapper code for sending messages to a web messaging environment (ME). As per the IPSME specification a reflector is required to reflect messages from this ME to other MEs e.g., the ME of the operating system.

IPSME- Idempotent Publish/Subscribe Messaging Environment

https://dl.acm.org/doi/abs/10.1145/3458307.3460966

Subscribing

function ipsme_handler_(msg) {
	console.log('ipsme_handler_: msg: ', msg);
	try {
		// add handlers ...	
	}
	catch(e) {
		// ...
	}
	console.log("ipsme_handler_: DROP! msg: ", msg);
}

IPSME_MsgEnv.subscribe(ipsme_handler_);

It is by design that a participant receives the messages it has published itself. If this is not desirable, each message can contain a "referer" (sic) identifier and a clause added in the ipsme_handler_ to drop those messages containing the participant's own referer id.

Publishing

IPSME_MsgEnv.publish( ... );

Discussion

The ME utilized, as so mentioned in the name, is broadcast channel. This "library" is entirely optional. IPSME dictates the use of a readily available pubsub. That means the code is roughly equal to the following:

Subscribing

const bc= new  BroadcastChannel('IPSME');
bc.onmessage= function(event) {
	const  msg= event.data;
	// add handlers here ...
}

I have chosen to use the 'IPSME' channel name although the IPSME specification doesn't divide communication into different channels; all IPSME participants receive all messages. Each channel is equal to a different ME with respect to the IPSME conventions.

Publishing

bc.postMessage(msg);