Service feature table (Cache)

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Display a feature layer from a service using the on interaction cache feature request mode.

Image of service feature table on interaction cache

Use case

Service feature tables support three request modes, which define how features are requested from the service and stored in the local table. The feature request modes have different performance characteristics. Use On interaction cache in scenarios with large amounts of infrequently edited data. See Table performance concepts in the ArcGIS Runtime SDK for Android guide to learn more.

How to use the sample

Run the sample and pan and zoom around the map. With each interaction, features will be requested and stored in a local cache. Each subsequent interaction will display features from the cache and only request new features from the service.

How it works

  1. Set the ServiceFeatureTable.setFeatureRequestMode(...) property of the service feature table to ON_INTERACTION_CACHE before the table is loaded.
  2. Add the table to the map using a FeatureLayer; features will be requested for the visible extent as the user pans and zooms.

Relevant API

  • FeatureLayer
  • FeatureRequestMode.ONINTERACTIONCACHE
  • ServiceFeatureTable
  • ServiceFeatureTable.setFeatureRequestMode

About the data

The sample opens with an initial visible extent centered over pool permit statuses in California.

Additional information

On interaction cache is the default feature request mode. Features are requested automatically for the visible extent as the users pans and zooms the map. If the user returns to an area where features have previously been requested, those features won't be requested again.

Tags

cache, feature request mode, performance

Sample Code

MainActivity.java
                                                                                           
/* Copyright 2016 ESRI
 *
 * All rights reserved under the copyright laws of the United States
 * and applicable international laws, treaties, and conventions.
 *
 * You may freely redistribute and use this sample code, with or
 * without modification, provided you include the original copyright
 * notice and use restrictions.
 *
 * See the Sample code usage restrictions document for further information.
 *
 */

package com.esri.arcgisruntime.sample.servicefeaturetablecache;

import android.os.Bundle;

import androidx.appcompat.app.AppCompatActivity;
import com.esri.arcgisruntime.ArcGISRuntimeEnvironment;
import com.esri.arcgisruntime.data.ServiceFeatureTable;
import com.esri.arcgisruntime.geometry.Envelope;
import com.esri.arcgisruntime.geometry.SpatialReferences;
import com.esri.arcgisruntime.layers.FeatureLayer;
import com.esri.arcgisruntime.mapping.ArcGISMap;
import com.esri.arcgisruntime.mapping.BasemapStyle;
import com.esri.arcgisruntime.mapping.Viewpoint;
import com.esri.arcgisruntime.mapping.view.MapView;

public class MainActivity extends AppCompatActivity {

  MapView mMapView;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    // authentication with an API key or named user is required to access basemaps and other
    // location services
    ArcGISRuntimeEnvironment.setApiKey(BuildConfig.API_KEY);

    // inflate MapView from layout
    mMapView = findViewById(R.id.mapView);

    // create a map with the light grey canvas basemap
    ArcGISMap map = new ArcGISMap(BasemapStyle.ARCGIS_LIGHT_GRAY);

    // create feature layer with its service feature table
    // create the service feature table
    ServiceFeatureTable serviceFeatureTable = new ServiceFeatureTable(
        getResources().getString(R.string.sample_service_url));

    //explicitly set the mode to on interaction cache (which is also the default mode for service feature tables)
    serviceFeatureTable.setFeatureRequestMode(ServiceFeatureTable.FeatureRequestMode.ON_INTERACTION_CACHE);

    // create the feature layer using the service feature table
    FeatureLayer featureLayer = new FeatureLayer(serviceFeatureTable);

    // add the layer to the map
    map.getOperationalLayers().add(featureLayer);

    // set the map to be displayed in the mapview
    mMapView.setMap(map);

    // set an initial viewpoint
    mMapView.setViewpoint(new Viewpoint(
        new Envelope(-1.30758164047166E7, 4014771.46954516, -1.30730056797177E7, 4016869.78617381,
            SpatialReferences.getWebMercator())));
  }

  @Override
  protected void onPause() {
    super.onPause();
    // pause MapView
    mMapView.pause();
  }

  @Override
  protected void onResume() {
    super.onResume();
    // resume MapView
    mMapView.resume();
  }

  @Override
  protected void onDestroy() {
    super.onDestroy();
    // dispose MapView
    mMapView.dispose();
  }
}