This sample demonstrates how to override the default cluster symbol when clustering is enabled on a GeoJSONLayer. Clustering is a method of reducing features in a FeatureLayer, CSVLayer, GeoJSONLayer, WFSLayer, or OGCFeatureLayer by grouping them based on their spatial proximity to one another. Typically, clusters are proportionally sized based on the number of features within each cluster.
Clustering is configured in the featureReduction property of the layer. The feature reduction property gives you control over many cluster properties, including the cluster symbol. This allows you to retain the layer’s renderer for styling individual features, but visually indicate clusters with a dedicated symbol.
Configure cluster symbol
const clusterConfig = { type: "cluster", clusterRadius: "100px", popupTemplate: { title: "Cluster summary", content: "This cluster represents {cluster_count} earthquakes.", fieldInfos: [ { fieldName: "cluster_count", format: { places: 0, digitSeparator: true, }, }, ], }, clusterMinSize: "24px", clusterMaxSize: "60px",
symbol: { type: "simple-marker", style: "circle", color: "#69dcff", outline: { color: "rgba(0, 139, 174, 0.5)", width: 6, }, },
labelingInfo: [ { deconflictionStrategy: "none", labelExpressionInfo: { expression: "Text($feature.cluster_count, '#,###')", }, symbol: { type: "text", color: "#004a5d", font: { weight: "bold", family: "Noto Sans", size: "12px", }, }, labelPlacement: "center-center", }, ], };