Bounding Box Coordinates - arcgis

Question

I was reading the ArcGIS API for JavaScript version 4.14 documentation and cannot find an answer.
I'm spending hours looking into your documentation but it seems I cannot find a way to do a simple thing that can be done with any other mapping library (see Google Maps, Mapbox, Here etc etc).
I have a Map and a MapView, I would like to have the points of the bounding box of the map/mapview every time the map changes (North East / South West) to trigger a search on the database only on this area.
The map works perfectly, I'm trying to use the watcher:
viewMap.watch("stationary", function (status) {
if (status) {
PerformSearch();
}
});
function PerformSearch() {
var searchOptions = {
CurrentPage: 1,
Boundaries: { North: viewMap.extent.ymax, East: viewMap.extent.xmax, South: viewMap.extent.ymin, West: viewMap.extent.xmin },
....
}
But i see that viewMap.extent gives me a spatial reference that is not valid for me, I would like to just have the position as latitude and longitude of both points.
Is there a way to do it?
Many thanks... Any help would be apreciated!

Answer 1

The coordinates of the extent of the view are in the spatial reference system of the map, and this is determined by the spatial reference system of the basemap layer. If you are using Web Maps, like ESRI, OpenStreetMap, etc, then is Web Mercator WKT 3857.
Now, in order to get latitude/longitude you need to transform to Geographic coordinates. In this case you can use webMercatorUtils to obtain a transformed extent, something like this,
let geoExt = webMercatorUtils.webMercatorToGeographic(viewmap.extent);
ArcGIS API Doc webMercatorUtils