Blank Popup when clicking on the map Leaflet-WMS

Question

I created an interactive map using Leaflet, when I click on my layers I can get data in popup, my problem is that when I click on the map where there are no features it shows a blank popup. I want to block this popup when it's blank.

This my code:

map.addEventListener('click', onMapClick);
popup = new L.Popup({maxWidth: 1000});
function onMapClick(e) {
var latlngStr = '(' + e.latlng.lat.toFixed(3) + ', ' +         e.latlng.lng.toFixed(3) + ')';
var BBOX =         map.getBounds()._southWest.lng+","+map.getBounds()._southWest.lat+","+map.getBounds()._northEast.lng+","
+map.getBounds()._northEast.lat;
var WIDTH= map.getSize().x;
var HEIGHT = map.getSize().y;
var X = map.layerPointToContainerPoint(e.layerPoint).x;
var Y = map.layerPointToContainerPoint(e.layerPoint).y;
var layerObj = {};
layerObj["test_layer:EV_Lot_ALHOUDA_wgs"] = alhouda6_layer;
layerObj["test_layer:Imm_Coll_Lot_ALHOUDA_wgs84"] =alhouda7_layer;
layerObj["test_layer:Villa_Lot_ALHOUDA_wgs84"] = alhouda8_layer; 
layerObj["test_layer:Eco_Lot_ALHOUDA_wgs84"] =alhouda5_layer;
layerObj["test_layer:Equip_Lot_ALHOUDA_wgs84"] = alhouda4_layer; 
layerObj["test_layer:Rec_Lot_ALHOUDA_wgs84"] =alhouda3_layer;
layerObj["test_layer:Parking_Lot_ALHOUDA_wgs84"] = alhouda2_layer; 
layerObj["test_layer:P200Log_Lot_ALHOUDA_wgs84"] =alhouda1_layer;

layerObj["test_layer:R3_Lot_HFOUNTY_wgs84"] =founty1_layer;
layerObj["test_layer:R5_Lot_HFOUNTY_wgs84"] =founty2_layer;    
layerObj["test_layer:R9_Lot_HFOUNTY"] =founty3_layer;
layerObj["test_layer:R15_Lot_HFOUNTY_wgs84"] =founty4_layer;
layerObj["test_layer:R1_Lot_HFOUNTY_wgs84"] =founty5_layer;
layerObj["test_layer:R2_Lot_HFOUNTY_wgs84"] =founty6_layer; 
layerObj["test_layer:Equip_Lot_HFOUNTY_wgs84"] =founty7_layer;  
 queryLayers = [];
for (key in layerObj) { 
if(map.hasLayer(layerObj[key])) {
 queryLayers.push(key);
 }
}
var urlLayers = queryLayers.join();

var URL = 'http://localhost:8082/geoserver/test_layer/wms?SERVICE=WMS&VERSION=1.1.1&REQUEST=GetFeatureInfo&LAYERS=test_layer:Imm_Coll_Lot_ALHOUDA_wgs84,test_layer:Villa_Lot_ALHOUDA_wgs84,test_layer:Eco_Lot_ALHOUDA_wgs84,test_layer:Equip_Lot_ALHOUDA_wgs84,test_layer:Rec_Lot_ALHOUDA_wgs84,test_layer:EV_Lot_ALHOUDA_wgs,test_layer:P200Log_Lot_ALHOUDA_wgs84,test_layer:Parking_Lot_ALHOUDA_wgs84,R3_Lot_HFOUNTY_wgs84,R5_Lot_HFOUNTY_wgs84,R9_Lot_HFOUNTY,R15_Lot_HFOUNTY_wgs84,R1_Lot_HFOUNTY_wgs84,R2_Lot_HFOUNTY_wgs84,Equip_Lot_HFOUNTY_wgs84&QUERY_LAYERS='+urlLayers+'&propertyName=Zone_Urb,Type_Urb&STYLES=&BBOX='+BBOX+'&FEATURE_COUNT=5&HEIGHT='+HEIGHT+'&WIDTH='+WIDTH+'&FORMAT=image%2Fpng&INFO_FORMAT=text%2fhtml&SRS=EPSG%3A4326&X='+X+'&Y='+Y;
 popup.setLatLng(e.latlng);
popup.setContent("<iframe src='"+URL+"' width='400' height='100' frameborder='0'></iframe>");
if (urlLayers)

map.openPopup(popup); 

Answer 1

You would like to check if you received results, the array urlLayers exists, but you wanna check its length.
Try changing the condition if(urlLayers) - > if(urlLayers.length > 0)