LayerList API 4.3 obtain Id of the sublayer on toggle

Question

Hi All, I'm kind of new on the API 4.3 and I've bean searching everywhere but cant find the answer. What I basically want to do is that when that all of my sublayers are not visible as default. When the user clicks a sublayer for viewing I would like to get the ID of the sublayer the user clicked so that I can refresh the search widget son that the user can search on the visible sublayer. i read that with the ListItem you can grab it but i don't know how to invoque that parameter on click Hope someone can help me. Here is a snippet of how I'm loading the #LayerList‌ layer = new MapImageLayer({ url: URL }); var view = new MapView({ map: map, container: "viewDiv", extent: extent }); var layerList = new LayerList({ view: view }); view.ui.add(layerList, "top-right");‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

KristianEkenes · Accepted Answer

You would need to watch the visible property of the ListItem, then grab the ID of the sublayer when the value is true:

if (item.layer.declaredClass === "esri.layers.support.Sublayer") {
  watchUtils.whenTrue(item, "visible", function(newVal) {
    console.log("sub layer id of visible layer: ", item.layer.id);
  });
}‍‍‍‍‍

Here's a live app based on the SDK sample: https://codepen.io/kekenes/pen/zdxJpX?editors=1001