Get list of layers from map service - v3.6 API

[GISAdmin1]

I am having trouble getting a list of layers from a map service automatically.  If I assign the get layer list function to a button, I have no problem.  Here is

require(["esri/map", "esri/geometry/Extent", "esri/layers/ArcGISTiledMapServiceLayer", "esri/layers/ArcGISDynamicMapServiceLayer" ,"dojo/domReady!"], function(Map, Extent, ArcGISTiledMapServiceLayer,ArcGISDynamicMapServiceLayer,LayerInfo) {  var map = new Map("map", {extent: new Extent({"xmin":506835.3785030904,"ymin":5439759.165184998,"xmax":515698.93789687584,"ymax":5450607.1035475405,"spatialReference":{"wkid":26910}})  });  var baseMap = new ArcGISTiledMapServiceLayer("http://cosmos.surrey.ca/COSREST/rest/services/Base_Map_All_Scales/MapServer"); allCityHighUse = new ArcGISDynamicMapServiceLayer("http://cosmosbeta.surrey.ca/COSREST/rest/services/Public/MapServer"); map.addLayer(baseMap, allCityHighUse);  });   alert(getlayerID ('Test Layer'));  function getlayerId(layerName) {               var layerInfos =  allCityHighUse.layerInfos;                 for (var i=0, il=layerInfos.length; i<il; i++) {             var templayerName = layerInfos.name;             var layerId = layerInfos.id;                            if (templayerName == layerName) {                 alert(layerId);               }             return layerId;          }    }  

Any idea why?  If I console.log (allCityHighUse), during runtime I see the layerInfos object is populated.

[KenBuja · Accepted solution]

What's happening is the alert fires before the layer is ready. You should run that function in the layer's load event or the map's layers-add-result event.

require(["esri/map", "esri/geometry/Extent", "esri/layers/ArcGISTiledMapServiceLayer", "esri/layers/ArcGISDynamicMapServiceLayer" ,"dojo/domReady!"], function(Map, Extent, ArcGISTiledMapServiceLayer,ArcGISDynamicMapServiceLayer,LayerInfo) {     var map = new Map("map", {extent: new Extent({"xmin":506835.3785030904,"ymin":5439759.165184998,"xmax":515698.93789687584,"ymax":5450607.1035475405,"spatialReference":{"wkid":26910}})  });     var baseMap = new ArcGISTiledMapServiceLayer("http://cosmos.surrey.ca/COSREST/rest/services/Base_Map_All_Scales/MapServer");     allCityHighUse = new ArcGISDynamicMapServiceLayer("http://cosmosbeta.surrey.ca/COSREST/rest/services/Public/MapServer");     map.addLayer(baseMap, allCityHighUse);      allCityHighUse.on("load" function () {         alert(getlayerID ('Test Layer'));     });      //or     //map.on("layers-add-result", function() {     //    alert(getlayerID ('Test Layer'));     //});    });      //alert(getlayerID ('Test Layer'));  function getlayerId(layerName) {                         var layerInfos =  allCityHighUse.layerInfos;                    for (var i=0, il=layerInfos.length; i<il; i++) {         var templayerName = layerInfos.name;         var layerId = layerInfos.id;                                      if (templayerName == layerName) {             alert(layerId);         }         return layerId;     } }