Class EventEmitter

Example

class Logger extends EventEmitter {
   onLog(log:string) { console.log(log); } // behavior by default

   test() {
      // raise event onLog
      this.onLog('test');
   }
}

const logger = new Logger();
logger.test(); // displays a log 'test'

// redefine default behavior to display nothing
logger.onLog = () => {}
logger.test(); // displays nothing

// add an additionnal subscription
logger.on('log', console.log);
logger.test(); // displays a log 'test'

// remove the additionnal subscription
logger.off('log', console.log);
logger.test(); // displays nothing

// add two additionnal subscriptions with a AbortController
const controller = new AbortController();
logger.on('log', log => console.log(log), controller);
logger.on('log', log => console.error(log), controller);
logger.test(); // displays a log 'test' + an error 'test'

// Unsubscribe all the subscription with the AbortController
controller.abort();
logger.test(); // displays nothing
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