181648 2018-01-15 06:55:05 -0800 Service worker postMessage 2018-01-16 01:29:14 -0800 1 1 1 Unclassified WebKit New Bugs Safari Technology Preview Mac macOS 10.13 RESOLVED DUPLICATE 178940 P2 Blocker --- 1 coertzen.jfs webkit-unassigned beidson cdumez youennf oldest_to_newest 1389287 0 coertzen.jfs 2018-01-15 06:55:05 -0800 Still getting Error: Passing MessagePort objects to postMessage is not yet supported postMessage@[native code] Code: var msg_chan = new MessageChannel(); msg_chan.port1.onmessage = function(event) { if (event.data.error) { console.log(event.data.error, true); } else { Web.AppCache.ServiceWorkerStartCaching(); } } if (navigator.serviceWorker.controller) navigator.serviceWorker.controller.postMessage({ 'action': 'ClearCache' }, [msg_chan.port2]); else if (Web.ServiceWorkerReg.active) Web.ServiceWorkerReg.active.postMessage({ 'action': 'ClearCache' }, [msg_chan.port2]); 1389478 1 youennf 2018-01-16 01:21:02 -0800 Thanks Stephan, this is a known limitation. I will dupe it with https://bugs.webkit.org/show_bug.cgi?id=178940. Do not hesitate to give feedback on how important it is for you. *** This bug has been marked as a duplicate of bug 178940 *** 1389483 2 coertzen.jfs 2018-01-16 01:29:14 -0800 Thank you. It's important for our application because we need it to be compatible with all browsers (cross platform) regarding offline support. We used applicationCache before but in future browser releases the Service Worker will replace it. Thanks for indicating that you guys are looking at supporting MessageChannel parameter passing.