Right now when editing coordinates, there's no feedback about whether they're valid or not until you after you submit the form. It would be better if the interface would respond straightaway so that the user knows their input won't be accepted.

Since trying to duplicate the Perl parsing/validation in Javascript would be a bad idea, I imagine we would need something like a /ws/js/ endpoint which takes a string and tries to parse it and if it succeeds, returns the parsed coordinates, otherwise an error. Then the site would call the endpoint when the user edits the field and show some sort of feedback for it.

The minimum feedback would be to turn the field green/red depending on whether it was successfully parsed or not. Something a bit more useful than that would be to show a bubble with the coordinates and a link to a map, so that the user can open the map to check the position is correct. The most useful thing would be to show a map of where the coordinates are on the page itself. That would then tie into MBS-6829 nicely - the user could either enter coordinates and have the map update, or select on the map and have the coordinates update.