Query features from a FeatureLayerView

The FeatureLayerView provides access to a layer's features that are displayed in the view. This sample uses the whenLayerView() method to get the FeatureLayer's layer view once it's created.

1 2 const layerView = await view.whenLayerView(featureLayer); // do something with the layerView

Once the layer view is available, you need to set up a watch on the dataUpdating property of the layer view. You must wait for all the features to finish updating in the view before performing a query.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 reactiveUtils.when(  () => !layerView.dataUpdating,  async () => {  // query all the features available for drawing.  try {  const results = await layerView.queryFeatures({  geometry: view.extent,  returnGeometry: true,  orderByFields: ["GEOID"],  });   const graphics = results.features;  // do something with the resulting graphics  } catch (error) {  console.error("query failed: ", error);  }  }, );

Once you gain access to the graphics available to the layer view, you can use them for a variety of purposes, such as creating drop down menus, or lists, as this sample does. Once a list is created you can listen for click events on each list node and open a popup at the location of the feature when the corresponding node is clicked.

1 2 3 4 view.openPopup({  features: [result],  location: result.geometry.centroid, });

While the popup is typically used with a feature layer, you can also display the popup in response to a query or some other action that does not involve a graphic or a feature. For example, you can display a popup on the view when user clicks on a table row, or a list. The resulting popup in this sample is displayed at the center of a zip code polygon and its content and title will be populated from the features parameter.