Caculate all volume of objects in viewer- Autodesk Forge

Question

I want to caculate all volume of objects in viewer but return arrayVolume = [] and vol = 0; Where did I go wrong ? Thank in advanced for all

    $("#kl").click(function(){
viewer.model.getExternalIdMapping(data => kl(data));
function kl(data){
    var arrayVolume = [];
    var vol;
    for(var key in data){
        var dbId = data[key];
        viewer.getProperties(dbId, function(e){
            //console.log('Entire object response ',e);
            //console.log('Properties ',e.properties);
            var propertiesObj = e.properties;
            propertiesObj.forEach(obj => {
                if(obj.displayName === "Volume"){
                    var volume = obj.displayValue;
                    arrayVolume.push(volume);
                }
            });
        });
    }
    vol= arrayVolume.reduce(function(a,b){return a+ b;},0)
    alert('w: '+arrayVolume);
    alert('w: '+vol);
}

question from:https://stackoverflow.com/questions/66058260/caculate-all-volume-of-objects-in-viewer-autodesk-forge

Answer 1

Be careful about synchronous vs. asynchronous code. The viewer.getProperties method is asynchronous, meaning that the callback you provided might be called later. In your code snippet the two alert calls are most likely called before the arrayVolume and vol properties are populated with your callback function.

Also, note that when you need to retrieve properties from more than one dbID, there's a better method for that: https://forge.autodesk.com/en/docs/viewer/v7/reference/Viewing/Model/#getbulkproperties-dbids-options-onsuccesscallback-onerrorcallback.