onconnect = function(e) { try { var port = e.ports[0] var source = new EventSource("../resources/message.py") source.onopen = function(e) { port.postMessage([true, source.readyState, 'data' in e, e.bubbles, e.cancelable]) this.close() } } catch(e) { port.postMessage([false, String(e)]) } }