topic iterate through sub-layers in ArcGIS JavaScript Maps SDK Questions

iterate through sub-layers

BrianFoley1 — Tue, 13 Sep 2016 15:34:49 GMT

I have a dynamicmapservicelayer (dynaLayer1) that has three layers. Each layer then has at least 2 sub-layers beneath it.

dynaLayer1

----> Layer 1

--------> Sub-Layer 1

--------> Sub-Layer 2

----> Layer 2

--------> Sub-Layer 1

--------> Sub-Layer 2

----> Layer 3

--------> Sub-Layer 1

--------> Sub-Layer 2

I am using the following code to get the layers. How can I get to the sub-layers (Sub-Layer 1 & 2) below that ?

Thanks.

dojo.connect(dynaLayer1, "onLoad", function () {
    var infos = dynaLayer1.layerInfos;
        for (var i = 0; i <= infos.length - 1; i++) {
                var layerId = infos.id;
                var layerName = infos.name;
                var layerVisible = infos.defaultVisibility;

alert("layerId : " + layerId + ".....layerName : " + layerName + ".....visible : " + layerVisible);
} })

Re: iterate through sub-layers

Drew — Tue, 13 Sep 2016 15:51:34 GMT

The layerInfos class has a "subLayerIds" property.
That will give you the Id's you need.

LayerInfo | API Reference | ArcGIS API for JavaScript 3.17

Re: iterate through sub-layers

BrianFoley1 — Tue, 13 Sep 2016 16:49:17 GMT

Andrew,

When I run the code, the subLayerIds is null. Also, how can I get the name of the sub-layer ?

Brian

Re: iterate through sub-layers

Drew — Tue, 13 Sep 2016 17:02:32 GMT

If "subLayerIds" is null then something else is wrong. Try publishing your service again and look at the REST endpoint to ensure they exist.

To get the name you just need to get the LayerInfo of the item..

var layerName = infos[mySubLayerId].name;‍

Re: iterate through sub-layers

RobertScheitlin__GISP — Tue, 13 Sep 2016 17:17:58 GMT

The subLayerIds will always be null if it is not a parent layer(meaning that the layer is not a grouped layer). You should check if the parentLayerId is not null before worrying about subLayerIds.

Re: iterate through sub-layers

BrianFoley1 — Tue, 13 Sep 2016 17:47:52 GMT

The parentId is -1.

This is my code :

var initialExtent = new Extent
(
        {
                 xmin: -8119646.38042271,
                 ymin: 4986891.42830988,
                 xmax: -8102329.13378822,
                 ymax: 4999699.14992532,
                  "spatialReference": { "wkid": 102100 }
          }
);

map = new Map("map", {
            extent: initialExtent,
            smartNavigation: false,
            slider: false,
            zoom: 14
});

baseLayer = new esri.layers.ArcGISTiledMapServiceLayer("http://server.arcgisonline.com/ArcGIS/rest/services/World_Street_Map/MapServer");
map.addLayer(baseLayer);

dynaLayer1 = new esri.layers.ArcGISDynamicMapServiceLayer ( "https://xxxxxxxxxx/ArcGIS/rest/services/xxxxx/Contaminated_Areas",

{

id: "Contaminated Areas", opacity: 0.8

}

);
dynaLayer1.setVisibleLayers([0, 1, 2]);

map.addLayers([dynaLayer1]);

dojo.connect(dynaLayer1, "onLoad", function () {
        var infos = dynaLayer1.layerInfos;
        for (var i = 0; i <= infos.length - 1; i++) {
              var layerId = infos.id;
              var layerName = infos.name;
              var layerVisible = infos.defaultVisibility;

//alert("layerId : " + layerId + ".....layerName : " + layerName + ".....visible : " + layerVisible);
}
})

Re: iterate through sub-layers

Drew — Tue, 13 Sep 2016 18:33:48 GMT

Here is a sample i made using some public data
Edit fiddle - JSFiddle