LayerList reload not working

DougCollins — Wed, 11 May 2016 21:42:32 GMT

I have an application where I need to switch out layers when a user makes a selection from a dropdownlist. I have the switching of the layers working fine, but I cannot get the LayerList to refresh with the newly selected layer. The LayerList works fine when the application loads, but when a layer is switched it does not work. I have tried to use the refresh method but that does not seem to work. Perhaps I am doing something wrong. I have a simplified version of what I am trying to do in the Javascript code below. I am using JS API version 3.16.

Thanks,

Charlie

require([

"dojo/dom", "dojo/parser", "dojo/on", "dojo/query", "dojo/dom-class",

"dojo/dom-style", "dojo/dom-construct",

"esri/map",

"esri/layers/ArcGISDynamicMapServiceLayer",

"dijit/registry",

"esri/dijit/LayerList",

"dijit/form/Button",

"dijit/layout/BorderContainer",

"dijit/layout/TabContainer",

"dijit/layout/ContentPane",

"dijit/TitlePane",

"dijit/Dialog",

"dijit/form/TextBox",

"dijit/form/ComboBox",

"dojo/domReady!"

], function(

dom, parser, on, query, domClass,

domStyle, domConstruct,

Map, ArcGISDynamicMapServiceLayer,

registry, LayerList )

{

parser.parse();

// Define layers and URL variables

var dynamicLayer;

var staticLayer;

var dynLayerURL;

var staticURL = "https://sampleserver6.arcgisonline.com/arcgis/rest/services/NapervilleShelters/MapServer";

var layer1URL = "https://sampleserver6.arcgisonline.com/arcgis/rest/services/DamageAssessment/MapServer";

var layer2URL = "https://sampleserver6.arcgisonline.com/arcgis/rest/services/CommercialDamageAssessment/MapServer";

// Get the layer drop down list

var selectedLayer = registry.byId('layerDropDown');

selectedLayer.on('change', setLayer);

// Start out with layer selected in dropdownList

var layerValue = selectedLayer.get('value');

if (layerValue == '1') {

dynLayerURL = layer1URL;

}

else if (layerValue == '2') {

dynLayerURL = layer2URL;

}

map = new Map("mapPanel", {

center: [-98.2, 40.05],

zoom: 5,

basemap: "national-geographic"

});

// Define layers as ArcGISDynamicMapServiceLayers

dynamicLayer = new ArcGISDynamicMapServiceLayer(dynLayerURL, { visible: true });

staticLayer = new ArcGISDynamicMapServiceLayer(staticURL, { visible: true });

// Add the LayerList

var layerList = new LayerList({

map: map,

showLegend: true,

layers: [ {layer: staticLayer, id: "Shelters", sublayers: true}, {layer: dynamicLayer, id: "Assessment", sublayers: true}]

}, "legendDiv");

layerList.startup();

layerList.on('load', function(){

expandLayerList();

});

// ADD the LAYERS

map.addLayers([staticLayer, dynamicLayer]);

function loadDynamicLayer() {

// Remove the current dyamicLayer

map.removeLayer(dynamicLayer);

// Point the new Dynamic Layer URL to the dynamicLayer

dynamicLayer = new ArcGISDynamicMapServiceLayer(dynLayerURL, { visible: true });

map.addLayer(dynamicLayer);

// REFRESH the layerList (DOES NOT WORK)

// If I click on the layerList checkboxs, it gives me the error:

// TypeError: t.byId(...) is null ???

layerList.refresh();

}

function setLayer() {

var lyrValue = selectedLayer.get('value');

if (lyrValue == '1') {

dynLayerURL = layer1URL;

}

else if (lyrValue == '2') {

dynLayerURL = layer2URL;

}

// Load the newly selected dynamic layer

loadDynamicLayer();

}

function expandLayerList() {

query('.esriLayer').forEach(function(node){

domClass.add(node, "esriListExpand");

});

query('.esriToggleButton').forEach(function(node){

domClass.replace(node, "esri-icon-down", "esri-icon-right");

});

}

});

Re: LayerList reload not working

KenBuja — Sun, 12 Dec 2021 07:43:13 GMT

It may be that the dynamic layer isn't ready by the time the legend is refreshed. Try something like this (which needs the module "dojo/on" added)

dynamicLayer = new ArcGISDynamicMapServiceLayer(dynLayerURL, { visible: true });
map.addLayer(dynamicLayer);
on.once(dynamicLayer, "load", function(){
    layerList.refresh();
});

topic LayerList reload not working in ArcGIS JavaScript Maps SDK Questions

LayerList reload not working

Re: LayerList reload not working