topic Re: Convert map extent to UTM in Web AppBuilder Custom Widgets Questions

Convert map extent to UTM

rajujee — Fri, 27 Jul 2018 16:58:46 GMT

I have a widget that calculate map extent or lat/long.

I need to convert these values to UTM (Mercator). Could you please help. I have included my code below.

define([

'dojo/_base/declare',

'dojo/_base/lang',

'jimu/BaseWidget',

'jimu/WidgetManager'

function (

declare,

lang,

BaseWidget,

WidgetManager) {

var clazz = declare([BaseWidget], {

name: 'UrlButton',

baseClass: 'widget-urlbutton',

isOpening: false,

onOpen: function () {

if (!this.isOpening) {

this.isOpening = true;

//Get lat,long,scale start

var mapCeneter = this.map.extent.getCenter();

var lat = mapCeneter.getLatitude();

var lon = mapCeneter.getLongitude();

var minxx = this.map.extent.xmin;

var minyy = this.map.extent.ymin;

var maxxx = this.map.extent.xmax;

var maxyy = this.map.extent.ymax;

Do I have to use toUtm(point, conversionMode, addSpaces)

https://developers.arcgis.com/javascript/latest/api-reference/esri-geometry-coordinateFormatter.html#toUtm

Re: Convert map extent to UTM

KenBuja — Fri, 27 Jul 2018 17:56:42 GMT

It looks like you're developing 2-D widget...is that true? If so, you can't use toUTM since that's a 4.x object and 2-D widgets use 3.x.

Re: Convert map extent to UTM

RobertScheitlin__GISP — Fri, 27 Jul 2018 18:15:35 GMT

I would just take the geometry and use the GeometryService to project it to the UTM zone you are interested in.

Re: Convert map extent to UTM

rajujee — Fri, 27 Jul 2018 19:01:09 GMT

Thanks for prompt response. Could you share code or steps please.

Re: Convert map extent to UTM

RobertScheitlin__GISP — Sun, 12 Dec 2021 09:06:52 GMT

Raju,

The documentation has some code for that:

https://developers.arcgis.com/javascript/3/jsapi/geometryservice-amd.html#project

require([
  "esri/tasks/ProjectParameters", ... 
], function(ProjectParameters, ... ) {
  var params = new ProjectParameters();
  params.geometries = [point];
  params.outSR = outSR;
  params.transformation = transformation;
  gsvc.project(params);
  ...
});‍‍‍‍‍‍‍‍‍‍

Re: Convert map extent to UTM

rajujee — Wed, 21 Nov 2018 18:05:06 GMT

I didn't imagine It would be tough to convert lat,long into bbox. I am trying to use this function but getting stuck on gsvc. Could you please guide me what I is wrong in my code.

var params = new ProjectParameters();
                  params.geometries = [lat, lon];
                  params.outSR = 4326; // is it source transformation?
                  params.transformation = 4326; // is it destination transformation?

                  console.log(params)
                  var gsvc; // what kind of variable is required?
                  gsvc.project(params); // how I can get bbox from gsvc varaible?

Re: Convert map extent to UTM

RobertScheitlin__GISP — Wed, 21 Nov 2018 19:07:42 GMT

Raju,

The geometry service geometries property is expecting an array of geometries. You have giving it an array of Lat, Lon coordinates. Create a point class from your coordinates and then add that point class to the geometries array.

Re: Convert map extent to UTM

rajujee — Fri, 07 Dec 2018 22:05:17 GMT

Thanks Rob for being helpful. I am getting error TypeError: Cannot read property 'spatialReference' of undefined

var outSR = new SpatialReference({ wkid: 4326 });

                  var mapPnt = new Point(lon, lat);
                  var params = new ProjectParameters();
                  params.geometries = mapPnt;
                  params.outSR = 4326;
                  params.transformation = 4326;

var geometryService = esri.tasks.GeometryService("https://utility.arcgisonline.com/ArcGIS/rest/services/Geometry/GeometryServer");
geometryService.project(params);

Re: Convert map extent to UTM

RobertScheitlin__GISP — Fri, 07 Dec 2018 22:09:39 GMT

Raju,

You have not specified a SR when you created the Point.

var mapPnt = new Point(lon, lat, missing SpatialReference);

Re: Convert map extent to UTM

rajujee — Mon, 10 Dec 2018 14:10:02 GMT

I hope you have a nice weekend. I am still getting same error after adding spatial reference.

var outSR = new SpatialReference({ wkid: 4326 });

                  var mapPnt = new Point(lon, lat, outSR);
                  var params = new ProjectParameters();
                  params.geometries = mapPnt;
                  params.outSR = outSR;
                  params.transformation = 4326;

var geometryService = esri.tasks.GeometryService("https://utility.arcgisonline.com/ArcGIS/rest/services/Geometry/GeometryServer");
geometryService.project(params);

Do I have to use daw-complete to re-project?

// geometry service
var toolbar = new Draw(this.map);
toolbar.on("draw-omplete", addToMap);

addtoMap: function (evt) {
var graphic = new Graphic(evt.geometry, symbol);
map.graphics.add(graphic);
console.log(dojo.toJson(geometry.toJson()));

Re: Convert map extent to UTM

RobertScheitlin__GISP — Mon, 10 Dec 2018 14:11:52 GMT

Raju,

Notice that geometries is plural not singular.

params.geometries = [mapPnt];‍‍

Then

You are specifying that the point SR is 4326 and then you are saying you want to project it to 4326 by using this line:

params.outSR = outSR; ‍‍

???

Next you have:

params.transformation = 4326;‍

which is not correct. Depending on what the original points SR is and what SR you are projecting to you like do not need this at all.

Re: Convert map extent to UTM

RobertScheitlin__GISP — Thu, 13 Dec 2018 14:34:25 GMT

Raju,

Did this info help?