display lat/long in the pop-up of a projected point feature class?

[KyleGonterwitz]

Can I use Arcade Expression or another method to create a popup in ArcGIS Pro to display the Latitude and Longitude of a point that is defined in the Web Mercator projection?

I've tried some variations of the point and geometry functions based on this reference but I have not figured out the right combination or approach.

Why would I define my data in the web mercator project you might ask?  Well that's because I'm collecting these points in the collector app and using the esri basemaps.

I don't have to use arcade if there's another method, just want to perform that spatial reference conversion to dynamically display latitude and longitude without having to add XY fields.

Kyle

[HåkonDreyer]

Web Mercator to LL is fortunately a simple transformation. The Arcade below transforms the geometrys coordinates from WebMercator and use the transformed values to create a URL.

//wkid 102100->4326

var g = Geometry($feature);

var lon = g.x/111319.49079;

var lat = g.y/6378137.0;

lat = 90*(4*Atan(Exp(Lat)) - Pi)/Pi;

return "https://www.flightradar24.com/"+Round(lat, 5)+","+Round(lon, 5)+"/7"

[HåkonDreyer]

Oops, but my bad. Seems the Geometry() function is not available in Pro, only in Enterprise and AGOL

[DanPatterson_Retired]

I must admit I haven't used popups, but the help topic...

Pop-ups—ArcGIS Pro | ArcGIS Desktop 

states...

A pop-up, by default, shows a listing, grouped by layer, of all identified items and the attributes of one feature at a time. The attribute portion allows you the flexibility to view configured content (custom text, field-value pairs, charts, images, and so on).

Which suggests that perhaps having the data already in a text field as a concatenation of a Longitude-Latitude field might be one route.

[KyleGonterwitz]

My data is a hosted feature service for the collector app.  I don't want to have to calculate attribtues in the hosted feature service layer each time a point is added or moved or set up some nonsense CDC process to do this.

I dont actually need the lat/long in the popup, what I really need is the lat/long as URL tokens behind an image to link to google maps, bing maps, and most of all, mapillary at a particular location and scale.  If I could get the coordinates in the popup I can get them in a url expression I think, but the popup would be an easy test to see that yes, it can be done.  

I will look at the math solution there Håkon Dreyer maybe I can get that to work with the point[() function?  That is nice to know, I figured a mathematical projection calculation might be part of a solution.

Maybe I will take this to the Ideas page.  

[KyleGonterwitz]

In the popup configuratior  for the latest version of pro, there is an option to add text to the popup, then at the bottom of the configurator, a button for expressions. Click that button, then there is another button that says "new".  Click NEW then we get this window:

In this expression builder, there are only text, number, and date functions.  also in this expression builder, the SHAPE field is not presented as an actionable field.  

So, looks like a "cant be done" for now in pro.  To the ideas page!

[XanderBakker · Accepted solution]

I'm using ArcGIS Pro version 2.4.1 and the expression below works for me:

function MetersToLatLon(x, y) {
    var originShift = 2.0 * PI * 6378137.0 / 2.0;
    var lon = (x / originShift) * 180.0;
    var lat = (y / originShift) * 180.0;
    lat = 180.0 / PI * (2.0 * Atan( Exp( lat * PI / 180.0)) - PI / 2.0);
    return [lat, lon];
}

function convertToDms(dd, isLng) {
    var dir = "";
    if (dd < 0) {
        if (isLng) {
            dir = "E";
        } else {
            dir = "W";
        }
    } else {
        if (isLng) {
            dir = "S";
        } else {
            dir = "N";
        }
    }

    var absDd = Abs(dd);
    var deg = Floor(absDd, 0);
    var frac = absDd - deg;
    var min = Floor(frac * 60, 0);
    var sec = frac * 3600 - min * 60;
  
    // Round it to 2 decimal points.
    sec = Round(sec * 100) / 100;
    return deg + "°" + min + "'" + sec + '"' + dir;
}

var latlon = MetersToLatLon(Geometry($feature).X, Geometry($feature).Y);

var lat = convertToDms(latlon[0], False);
var Lon = convertToDms(latlon[1], False);

return lat + " ,  " + lon;‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍