MapImageLayer - Explore data from a dynamic workspace

Note: Support for 3D on mobile devices may vary, view the system requirements for more information.

This sample demonstrates how to use the Smart Mapping renderer creators to generate a renderer for a Sublayer created from a dynamic data layer. The dynamic layer joins ancestry data from a table in a dynamic workspace to a map service layer. Select elements are provided to the user, allowing him/her to dynamically change the renderer based on different ancestry variables and classification methods.

To generate a renderer using the Smart Mapping creator methods, you must first create a FeatureLayer using the same data source as the Sublayer. The createFeatureLayer() method is a convenience method for creating matching FeatureLayer instances from Sublayers.

// Get the sublayer to explore
const ancestrySublayer = layer.sublayers.find(function(sublayer) {
  return sublayer.title === "% population with selected ancestry";
});

const ancestryFeatureLayer = ancestrySublayer.createFeatureLayer();

Use the FeatureLayer instance to generate the renderer. Then set the output renderer back on the Sublayer instance.

const params = {
  // set FeatureLayer as input
  layer: ancestryFeatureLayer,
  basemap: map.basemap,
  // Arcade is used to normalize and round the data
  valueExpression: "Round( ( $feature['" + ancestrySelect.value + "'] / $feature['states.POP2007'] ) * 100, 1);",
  view: view,  // required with valueExpression
  classificationMethod: classSelect.value
};

colorRendererCreator.createClassBreaksRenderer(params)
  .then(function(response){
    // set the renderer on the sublayer
    ancestrySublayer.renderer = response.renderer;

  });

The select elements are placed within the LayerList widget's panel content. Note that individual list items can contain multiple content items within the same panel. In this case, we add the div element containing the select elements, and a Legend instance (indicated using the legend helper string) as an array of content items.

// Set LayerList with two content elements in the same panel
// 1. A div element containing the select elements for data exploration
// 2. a legend instance
const layerList = new LayerList({
  view: view,
  listItemCreatedFunction: function (event) {
    const item = event.item;
    item.panel = {
      content: [ document.getElementById("infoDiv"), "legend" ],
      open: true
    };
  }
});
view.ui.add(layerList, "top-right");