topic Re: get the extent of a featureLayer in ArcGIS JavaScript Maps SDK Questions

get the extent of a featureLayer

SaraEL_MALKI — Mon, 01 May 2017 16:11:02 GMT

Hi guys,

I want to get the extent of a featureLayer and Zoom to it, How I can Implement that in my code ?

function HideAllLayers() {

var layerIds = map.graphicsLayerIds;

var layer17 = map.getLayer(17); //I want to ZOOM to this Layer

var layer;

for (var i=0; i < layerIds.length; i++) {

layer = map.getLayer(layerIds[i]);

layer.hide();

}

$('#editModal').modal('hide'); //CLOSE THE MODAL

}

Re: get the extent of a featureLayer

RobertScheitlin__GISP — Mon, 01 May 2017 16:40:35 GMT

Sara,

Something like this:

map.setExtent(layer17.fullExtent, true);‍

Re: get the extent of a featureLayer

SaraEL_MALKI — Mon, 01 May 2017 19:07:49 GMT

It gives me an error, Uncaught TypeError: Cannot read property 'fullExtent' of undefined

Re: get the extent of a featureLayer

RobertScheitlin__GISP — Mon, 01 May 2017 19:35:54 GMT

Then you featurelayer is not loaded yet, or you are just not getting the featurelayer based on the code you are using. Have you checked to see if layer17 is a valid FL?

Re: get the extent of a featureLayer

SaraEL_MALKI — Mon, 01 May 2017 19:52:01 GMT

It does not throw an error if I write :

var layer17 = map.getLayer("graphicsLayer17"); //I want to ZOOM to this Layer

but It does nothing, I want it to zoom to that extent with a 11 level !

Re: get the extent of a featureLayer

RobertScheitlin__GISP — Mon, 01 May 2017 20:02:22 GMT

Yes that line may not through an error but have you checked the value of layer17?

console.log(layer17);

Re: get the extent of a featureLayer

SaraEL_MALKI — Mon, 01 May 2017 20:16:23 GMT

in the console "

console.log(layer17.fullExtent);

it gives:

Map: Geometry (wkid: PROJCS["zone1",GEOGCS["GCS_Merchich_Degree",DATUM["D_Merchich",SPHEROID["Clarke_1880_IGN",6378249.2,293.4660212936265]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],PROJECTION["Lambert_Conformal_Conic"],PARAMETER["False_Easting",500000.0],PARAMETER["False_Northing",300000.0],PARAMETER["Central_Meridian",-5.4],PARAMETER["Standard_Parallel_1",34.866],PARAMETER["Standard_Parallel_2",31.725],PARAMETER["Scale_Factor",1.0],PARAMETER["Latitude_Of_Origin",33.3],UNIT["Meter",1.0]]) cannot be converted to spatial reference of the map (wkid: 102100)

Re: get the extent of a featureLayer

RobertScheitlin__GISP — Mon, 01 May 2017 20:20:02 GMT

So that means that the layers WKID is different from the maps WKID of 102100 and you will have to project the layers full extent to 102100.

Re: get the extent of a featureLayer

SaraEL_MALKI — Mon, 01 May 2017 20:34:58 GMT

so how can I do that ?

Re: get the extent of a featureLayer

SaraEL_MALKI — Sun, 12 Dec 2021 00:55:10 GMT

I found these lines:

  var customExtentAndSR = new esri.geometry.Extent(-20037506,-9823074,20037506,10214431,new esri.SpatialReference({"wkid":54052}));
        //create map with new custom spatial reference and extent.  The map will be in the Goode Homolosine Land projection
        var map = new esri.Map("map", { extent: customExtentAndSR });

How can use them for the extent of the layers ?

Re: get the extent of a featureLayer

RobertScheitlin__GISP — Mon, 01 May 2017 20:42:23 GMT

Sara,

By using the GeometryService.project and ProjectParameters classes:

ProjectParameters | API Reference | ArcGIS API for JavaScript 3.20

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

Re: get the extent of a featureLayer

SaraEL_MALKI — Mon, 01 May 2017 20:51:33 GMT

Okay I will create a geometry Service and keep you in touch with what I've done,

thanks for your time

Re: get the extent of a featureLayer

KristianEkenes — Sun, 12 Dec 2021 00:55:13 GMT

Since layer.fullExtent isn't totally reliable, I suggest doing the following:

featureLayer.on("load", function(){
  var query = new Query();
  query.where = "1=1";
  query.outSpatialReference = new SpatialReference(3857);
      
  featureLayer.queryExtent(query, zoomToExtent);
});
    
function zoomToExtent(response){
  var extent = response.extent;
  map.setExtent(extent, true);
}‍‍‍‍‍‍‍‍‍‍‍‍

That way you don't have to bring in GeometryService and reproject geometries. Set the outSpatialReference to match the map and the resulting extent should be good. Here's a live demo of this as well: JS Bin - Collaborative JavaScript Debugging

Re: get the extent of a featureLayer

SaraEL_MALKI — Wed, 03 May 2017 21:35:15 GMT

Thanks so much for the live Demo, How can I add a zoom level in that Code ?

Re: get the extent of a featureLayer

KristianEkenes — Wed, 03 May 2017 22:10:54 GMT

How do you plan to use the zoom level?

Re: get the extent of a featureLayer

SaraEL_MALKI — Wed, 03 May 2017 22:17:54 GMT

I wanna zoom to that extent with a 10 level

Re: get the extent of a featureLayer

KristianEkenes — Wed, 03 May 2017 22:24:29 GMT

After setting the map extent call:

map.setZoom(10);

Re: get the extent of a featureLayer

SaraEL_MALKI — Wed, 03 May 2017 23:21:42 GMT

Thank you Kristian for your time