Limit the features displayed on a map with a definition expression.
Use case
Set a definition expression to filter out the features to be displayed. You might filter a dataset of tree quality selecting for only those trees which require maintenance or are damaged.
How to use the sample
Press the 'expression' button to limit the features requested from the feature layer to those specified by the SQL query definition expression. Click the 'expression' button again to de-press it and remove the definition expression on the feature layer, which returns all the records.
How it works
Create a service feature table from a URL.
Create a feature layer from the service feature table.
Set the limit of the features on your feature layer using FeatureLayer.setDefinitionExpression("Expression").
Relevant API
FeatureLayer
ServiceFeatureTable
About the data
This map displays point features related to crime incidents that have been reported by city residents.
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/*
* Copyright 2017 Esri.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy of
* the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/package com.esri.samples.feature_layer_definition_expression;
import javafx.application.Application;
import javafx.geometry.Insets;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.ToggleButton;
import javafx.scene.layout.StackPane;
import javafx.stage.Stage;
import com.esri.arcgisruntime.ArcGISRuntimeEnvironment;
import com.esri.arcgisruntime.data.ServiceFeatureTable;
import com.esri.arcgisruntime.geometry.Point;
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.view.MapView;
publicclassFeatureLayerDefinitionExpressionSampleextendsApplication{
private MapView mapView;
private FeatureLayer featureLayer;
privatefinalstatic String FEATURE_SERVICE_URL =
"https://sampleserver6.arcgisonline.com/arcgis/rest/services/SF311/FeatureServer/0";
@Overridepublicvoidstart(Stage stage){
try {
// create stack pane and application scene StackPane stackPane = new StackPane();
Scene scene = new Scene(stackPane);
scene.getStylesheets().add(getClass().getResource("/feature_layer_definition_expression/style.css").toExternalForm());
// set title, size, and add scene to stage stage.setTitle("Feature Layer Definition Expression Sample");
stage.setWidth(800);
stage.setHeight(700);
stage.setScene(scene);
stage.show();
// authentication with an API key or named user is required to access basemaps and other location services String yourAPIKey = System.getProperty("apiKey");
ArcGISRuntimeEnvironment.setApiKey(yourAPIKey);
// create renderer toggle switch ToggleButton definitionSwitch = new ToggleButton();
definitionSwitch.setText("expression");
// set the definition expression definitionSwitch.selectedProperty().addListener((observable, oldValue, newValue) -> {
if (definitionSwitch.isSelected()) {
featureLayer.setDefinitionExpression("req_Type = 'Tree Maintenance or Damage'");
} else {
// reset the definition expression featureLayer.setDefinitionExpression("");
}
});
// create service feature tablefinal ServiceFeatureTable featureTable = new ServiceFeatureTable(FEATURE_SERVICE_URL);
// create feature layer from service feature table featureLayer = new FeatureLayer(featureTable);
// create a map with the topographic basemap stylefinal ArcGISMap map = new ArcGISMap(BasemapStyle.ARCGIS_TOPOGRAPHIC);
// add the feature layer to the map's operational layers map.getOperationalLayers().add(featureLayer);
// create a map view and set the map to it mapView = new MapView();
mapView.setMap(map);
// starting location for sample Point startPoint = new Point(-13630845, 4544861, SpatialReferences.getWebMercator());
// set the viewpoint for the map view mapView.setViewpointCenterAsync(startPoint, 150000);
// add the map view and control panel to stack pane stackPane.getChildren().addAll(mapView, definitionSwitch);
StackPane.setAlignment(definitionSwitch, Pos.TOP_LEFT);
StackPane.setMargin(definitionSwitch, new Insets(10, 0, 0, 10));
} catch (Exception e) {
// on any error, display the stack trace e.printStackTrace();
}
}
/**
* Stops and releases all resources used in application.
*/@Overridepublicvoidstop(){
if (mapView != null) {
mapView.dispose();
}
}
/**
* Opens and runs application.
*
* @param args arguments passed to this application
*/publicstaticvoidmain(String[] args){
Application.launch(args);
}
}