IdentifyTask - complete event

Question

I wrote following code to show GIS attributes, whenever user clicks on the map. But IdentifyTask - complete event is being called multiple times. I am using ArcGIS JS API 3.9. I am able to see from the fiddler that REST request is fired only once and able to retrieve multiple features attributes. Sometimes, I have seen it is being called single time only even attributes are multiple. How to debug on this inconsistent behavior?

vMap.on('click', function(event){

var vIdentifyTask,

vIdentifyParams,

vIdentifyTaskDeferred;

vIdentifyTask = new IdentifyTask(url),

vIdentifyParams = new IdentifyParameters();

vIdentifyParams.tolerance = 3;

vIdentifyParams.returnGeometry = true;

vIdentifyParams.layerIds = [3,4];

vIdentifyParams.width = vMap.width;

vIdentifyParams.height = vMap.height;

vIdentifyParams.geometry = event.mapPoint;

vIdentifyParams.mapExtent = vMap.extent;

vIdentifyTask.on('complete', showAttributesPopup);

vIdentifyTask.on('error', showError);

vIdentifyTask.execute(vIdentifyParams);

function showAttributesPopup(featureResults) {

//this function is being called multiple times

}

function showError() {

}

});

BhavinSanghani · Answer

Yes, I did the same to fix the issue.

rscheitlin · Answer

Bhavin,

That should help. Most of the time I use a var to hold the on event that way I can call remove() on that var.

var mcEvt = on(vMap, 'click', function(event){ .....

mcEvt.remove();

BhavinSanghani · Answer

No, it was not in loop but probably my code was not de-registering 'click' event.

e.g. I have two map toolbar buttons. One is to draw the line on the map and another is to see the GIS attributes. At a time one button action will remain active. So, in my case, I click on buttonA and register the 'click' event. Then if I click on buttonB and register the 'click' event again but previously registered 'click' event was not getting removed automatically.

To fix it, I am making sure that whenever new events are getting registered, other events have been removed.

Hope this will help.