return value after querytask has completed

eddiequinlan

Hi,

I think I'm overlooking something very simple.

1.    I'm running a QueryTask in ActionScript.
2.    When it's complete, I want the returned value stored in a variable.

When I run the code the first iteration the "trace" show 0.  The next time it shows a value, which should have been the previous value... so on and so forth.





Here's the part of the code with the issue:

sQueryTask.addEventListener(QueryEvent.EXECUTE_COMPLETE, test);
sQueryTask.execute(sQuery);

trace(nsum);       ///     Problem is here..... first query is "0", second query is the correct value from the first query..... so on and so forth.

private function test(event:QueryEvent):void
{
         nsum = 0;
         var farray:Array = event.featureSet.features;
for each (var g:Graphic in farray)
{
  nsum = nsum + g.attributes.SAPRICE;
}
// all ok here;;;       Sums all of the Sales  Prices correctly
             trace(nsum);
}

The nsum variable is being set before my QueryTask has completed and returned the correct value.  uuuuggggggghhhhhhhh

Thank you in advance,
Eddie

IvanBespalov

1
From adobe reference

result:Function â?? Function that should be called when the request has completed successfully. Must have the following signature: 
public function (result:Object, token:Object = null):void;

void - Specifies that a function cannot return any value.

// variable=reciever layer
// function getLayer(layerId:Number):Layer returns some data with type Layer
var layer:Layer = myMap.getLayer(layerId);

// no variable=reciever
// function can not return any value
layer.refresh(); // refresh():void 

so what variable=reciever gets data, when your function works function onResult(featureSet:FeatureSet, token:Object = null):Number ?

2
function SearchSaleTable works, and never pause or stop working to wait your result or fault function. you need a pencil and a piece of paper (maybe even two pieces of paper) on which you describe everything in detail the entire cycle of receiving and processing data.

So the green part of code never wait for red part of code, right?

private function SearchSaleTable(tmp:ArrayCollection):Number
{
    cursor = tmp.createCursor();
    var t:String = new String;
    while(!cursor.afterLast)
    { 
        t = cursor.current.toString();
        var saleQueryTask:QueryTask = new QueryTask(); 

        saleQueryTask.url = "my url";
        saleQueryTask.showBusyCursor = true;
        saleQueryTask.useAMF = false;
        sQuery.where = "SAPROP = '" + t + "'" ;

        saleQueryTask.execute(sQuery, new AsyncResponder(onResult, onFault));

        function onResult(featureSet:FeatureSet, token:Object = null):void
        {
            nsum = 0;
            for each (var g:Graphic in featureSet.features)
            {
                nsum += g.attributes.SAPRICE; 
            }
            trace("on Result " + nsum);

            sumSaleValue = sumSaleValue + nsum;
        }
        function onFault(info:Object, token:Object = null):void
        {
            Alert.show(info.toString());
        } 
        cursor.moveNext() 
    } 
    return sumSaleValue; 
}

Try to remove/comment all places you call trace function.
Put in other places:

private function SearchSaleTable(tmp:ArrayCollection):Number
{
trace(">>>start of SearchSaleTable()");
...
...
trace("query send")
saleQueryTask.execute(sQuery, new AsyncResponder(onResult, onFault));
...
...
function onResult(featureSet:FeatureSet, token:Object = null):void
{
    trace("result recieve");
...
...
trace(">>>end of SearchSaleTable()");
return sumSaleValue;

my be it helps.