Async/Await -> Possible without return value?

Question

So, I have a function which does some asynchronous work.

The function currently looks like this ( setTimeout currently is implemented because I haven't managed to implement the async / await way correctly):

 function gatherAllRelevantReservationData(TimeFrameStartFromInputfield, TimeFrameEndFromInputfield, liebraum, liebsitz, reservationFromDatabaseTimeFramesStart, reservationFromDatabaseTimeFramesEnd){ console.log("reservationFromDatabaseTimeFramesStart inside gatherAllRelevantReservationData are ", reservationFromDatabaseTimeFramesStart, reservationFromDatabaseTimeFramesEnd) //console.log("TimeFrameStartFromInputfield and TimeFrameEndFromInputfield inside gatherAllRelevantReservationData are ", TimeFrameStartFromInputfield, TimeFrameEndFromInputfield) var timeFrameAsObject = convertDateStringToJavaScriptDateTimeObject(TimeFrameStartFromInputfield, TimeFrameEndFromInputfield) var startDateAsObject = timeFrameAsObject.start var endDateAsObject = timeFrameAsObject.end var timeFrameAsUnixTimeStamp = ConvertToCustomizedUnixTimestampString(startDateAsObject, endDateAsObject) var startDateAsUnixTimeStamp = timeFrameAsUnixTimeStamp.start; var endDateAsUnixTimeStamp = timeFrameAsUnixTimeStamp.end; getTable(startDateAsUnixTimeStamp, endDateAsUnixTimeStamp, liebraum); if(FavSeatcheckHasBeenEnabled == 1){ setTimeout(function(){ prepareSelectedAndDatabaseDateStringsForComparison(startDateAsObject, endDateAsObject, liebraum, liebsitz, reservationFromDatabaseTimeFramesStart, reservationFromDatabaseTimeFramesEnd); }, 300) } }; 

The getTable function requires some time and needs to have finished before prepareSelectedAndDatabaseDateStringsForComparison is called. The problem is that getTable doesn't have any return value.

I'm pretty new to ES7 async / await features as well as to ES6 promises. I know that await usually expects some promise to be returned, and I probably could arrange this in some very hacky, nasty way.

But I'd like to know if there is any other, elegant way around this.

Ideally, I'd just like to attach async to gatherAllRelevantReservationData and then put an "await" in front of getTable call, but this of course did not work.

Any ideas how I could solve this?

EDIT: Here is the "getTable" function:

 function getTable(start, ende, liebraum) { //console.log("start in getTable is " + start) //console.log("ende in getTable is " + ende) fillRooms(liebraum); $.post("../include/returnTable.php", { anfang: start, ende: ende, art: art }, function(data){ document.getElementById("tablediv").innerHTML= data; console.log("start inside callback of AJAX inside getTabel is ", start) //console.log("data after getTable function " + data); //fillRooms(liebraum); }) } 

Answer 1

If you wish to use async / await , you need to change getTable to return a Promise (or some thenable), because only they can be await ed.

Fix your getTable to return the $.post call, so that its success can then be detected in gatherAllRelevantReservationData function, and then you can simply await the call of getTable :

async function gatherAllRelevantReservationData(...) {
  ...
  await getTable(...);
  ...
}
function getTable(start, ende, liebraum) {
  fillRooms(liebraum);
  return $.post("../include/returnTable.php", {
    anfang: start,
    ende: ende,
    art: art
  }, function(data) {
    document.getElementById("tablediv").innerHTML = data;
  })
}