Edit Feature Attachments

Demonstrates how you can add, delete, and fetch an attachment from a Feature in a FeatureLayer.

How it works

To get a Feature from a ServiceFeatureTable and add or delete Attachment:

  1. Create a service feature table from a URL.
  2. Create a FeatureLayer from the service feature table.
  3. Select features from the feature layer, FeatureLayer.selectFeatures().
  4. To fetch the feature's attachments, cast to an ArcGISFeature and use ArcGISFeature.fetchAttachmentsAsync().
  5. To add an attachment to the selected ArcGISFeature, create an attachment and use ArcGISFeature.addAttachmentAsync().
  6. To delete an attachment from the selected ArcGISFeature, use the ArcGISFeature.deleteAttachmentAsync().
  7. After a change, apply the changes to the server using ServiceFeatureTable.applyEditsAsync().

Code

/*
 * 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.editing.edit_feature_attachments;

import java.util.List;
import java.util.concurrent.ExecutionException;

import javafx.application.Application;
import javafx.application.Platform;
import javafx.geometry.Insets;
import javafx.geometry.Point2D;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.Alert;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.control.ListView;
import javafx.scene.input.MouseButton;
import javafx.scene.layout.Background;
import javafx.scene.layout.BackgroundFill;
import javafx.scene.layout.CornerRadii;
import javafx.scene.layout.StackPane;
import javafx.scene.layout.VBox;
import javafx.scene.paint.Paint;
import javafx.stage.Stage;

import org.apache.commons.io.IOUtils;

import com.esri.arcgisruntime.concurrent.ListenableFuture;
import com.esri.arcgisruntime.data.ArcGISFeature;
import com.esri.arcgisruntime.data.Attachment;
import com.esri.arcgisruntime.data.FeatureEditResult;
import com.esri.arcgisruntime.data.ServiceFeatureTable;
import com.esri.arcgisruntime.layers.FeatureLayer;
import com.esri.arcgisruntime.loadable.LoadStatus;
import com.esri.arcgisruntime.mapping.ArcGISMap;
import com.esri.arcgisruntime.mapping.Basemap;
import com.esri.arcgisruntime.mapping.GeoElement;
import com.esri.arcgisruntime.mapping.view.IdentifyLayerResult;
import com.esri.arcgisruntime.mapping.view.MapView;

public class EditFeatureAttachmentsSample extends Application {

  private ListView<String> attachmentList;
  private Label attachmentsLabel;
  private Button addAttachmentButton;
  private Button deleteAttachmentButton;

  private MapView mapView;
  private FeatureLayer featureLayer;
  private ServiceFeatureTable featureTable;

  private ArcGISFeature selected;
  private List<Attachment> attachments;

  private static final String SERVICE_FEATURE_URL =
      "http://sampleserver6.arcgisonline.com/arcgis/rest/services/DamageAssessment/FeatureServer/0";

  @Override
  public void start(Stage stage) {

    try {
      // create stack pane and application scene
      StackPane stackPane = new StackPane();
      Scene scene = new Scene(stackPane);
      scene.getStylesheets().add(getClass().getResource("/css/style.css").toExternalForm());

      // set title, size, and add scene to stage
      stage.setTitle("Edit Feature Attachments Sample");
      stage.setWidth(800);
      stage.setHeight(700);
      stage.setScene(scene);
      stage.show();

      // create a control panel
      VBox controlsVBox = new VBox(6);
      controlsVBox.setBackground(new Background(new BackgroundFill(Paint.valueOf("rgba(0,0,0,0.3)"), CornerRadii.EMPTY,
          Insets.EMPTY)));
      controlsVBox.setPadding(new Insets(10.0));
      controlsVBox.setMaxSize(180, 250);
      controlsVBox.getStyleClass().add("panel-region");

      // create a list to show selected feature's attachments
      attachmentList = new ListView<>();
      attachmentsLabel = new Label("Attachments: ");
      attachmentsLabel.getStyleClass().add("panel-label");
      attachmentList.getSelectionModel().selectedItemProperty().addListener((event) -> deleteAttachmentButton.setDisable(attachmentList.getSelectionModel().getSelectedIndex() == -1));

      // create add/delete buttons
      addAttachmentButton = new Button("Add Attachment");
      addAttachmentButton.setMaxWidth(Double.MAX_VALUE);
      addAttachmentButton.setDisable(true);

      deleteAttachmentButton = new Button("Delete Attachment");
      deleteAttachmentButton.setMaxWidth(Double.MAX_VALUE);
      deleteAttachmentButton.setDisable(true);

      // get image attachment
      byte[] image = IOUtils.toByteArray(getClass().getResourceAsStream("/symbols/destroyed.png"));

      // button click to add image attachment to selected feature
      addAttachmentButton.setOnAction(e -> addAttachment(image));

      // button click to delete selected attachment
      deleteAttachmentButton.setOnAction(e -> deleteAttachment(attachmentList.getSelectionModel().getSelectedIndex()));

      // add controls to the panel
      controlsVBox.getChildren().addAll(addAttachmentButton, deleteAttachmentButton, attachmentsLabel, attachmentList);

      // create a map with streets basemap
      ArcGISMap map = new ArcGISMap(Basemap.Type.STREETS, 40, -95, 4);

      // create service feature table from URL
      featureTable = new ServiceFeatureTable(SERVICE_FEATURE_URL);

      // create a feature layer from service feature table
      featureLayer = new FeatureLayer(featureTable);

      // selection options
      featureLayer.setSelectionColor(0xff0000ff);
      featureLayer.setSelectionWidth(10);

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

      // create a view for this ArcGISMap
      mapView = new MapView();

      // set ArcGISMap to be displayed in the view
      mapView.setMap(map);

      mapView.setOnMouseClicked(event -> {
        if (event.isStillSincePress() && event.getButton() == MouseButton.PRIMARY) {
          // create a map point from a point
          Point2D point = new Point2D(event.getX(), event.getY());

          // clear previous results
          featureLayer.clearSelection();
          addAttachmentButton.setDisable(true);
          attachmentList.getItems().clear();

          // get the clicked feature
          ListenableFuture<IdentifyLayerResult> results = mapView.identifyLayerAsync(featureLayer, point, 1, false);
          results.addDoneListener(() -> {
            try {
              IdentifyLayerResult layer = results.get();
              List<GeoElement> identified = layer.getElements();
              if (identified.size() > 0) {
                GeoElement element = identified.get(0);
                // get selected feature
                if (element instanceof ArcGISFeature) {
                  selected = (ArcGISFeature) element;
                  featureLayer.selectFeature(selected);
                  selected.loadAsync();
                  selected.addDoneLoadingListener(() -> {
                    if (selected.getLoadStatus() == LoadStatus.LOADED) {
                      fetchAttachments(selected);
                    } else {
                      Alert alert = new Alert(Alert.AlertType.ERROR, "Element Failed to Load!");
                      alert.show();
                    }
                  });
                  addAttachmentButton.setDisable(false);
                }
              }
            } catch (InterruptedException | ExecutionException e) {
              displayMessage("Exception getting identify result", e.getCause().getMessage());
            }
          });
        }
      });

      // add map view and control panel to stack pane
      stackPane.getChildren().addAll(mapView, controlsVBox);
      StackPane.setAlignment(controlsVBox, Pos.TOP_LEFT);
      StackPane.setMargin(controlsVBox, new Insets(10, 0, 0, 10));
    } catch (Exception e) {
      e.printStackTrace();
    }
  }

  /**
   * Updates the UI with a list of a feature's attachments.
   */
  private void fetchAttachments(ArcGISFeature feature) {

    ListenableFuture<List<Attachment>> attachmentResults = feature.fetchAttachmentsAsync();
    attachmentResults.addDoneListener(() -> {
      try {
        attachments = attachmentResults.get();

        // update UI attachments list
        Platform.runLater(() -> {
          attachmentList.getItems().clear();
          attachments.forEach(attachment -> attachmentList.getItems().add(attachment.getName()));
          if (!attachments.isEmpty()) {
            attachmentsLabel.setText("Attachments: ");
          } else {
            attachmentsLabel.setText("No Attachments!");
          }
        });
      } catch (InterruptedException | ExecutionException e) {
        displayMessage("Exception getting feature attachments", e.getCause().getMessage());
      }
    });
  }

  /**
   * Adds an attachment to a Feature.
   * 
   * @param attachment byte array of attachment
   */
  private void addAttachment(byte[] attachment) {

    if (selected.canEditAttachments()) {
      ListenableFuture<Attachment> addResult = selected.addAttachmentAsync(attachment, "image/png",
          "symbols/destroyed.png");
      addResult.addDoneListener(() -> {
        // update feature table
        ListenableFuture<Void> tableResult = featureTable.updateFeatureAsync(selected);

        // apply update to server when new feature is added, and update the
        // displayed list of attachments
        tableResult.addDoneListener(() -> applyEdits(featureTable));
      });
    } else {
      displayMessage(null, "Cannot add attachment.");
    }
  }

  /**
   * Deletes a selected attachment from a Feature.
   */
  private void deleteAttachment(int attachmentIndex) {

    if (selected.canEditAttachments()) {
      ListenableFuture<Void> deleteResult = selected.deleteAttachmentAsync(attachments.get(attachmentIndex));
      deleteResult.addDoneListener(() -> {
        // update feature table
        ListenableFuture<Void> tableResult = featureTable.updateFeatureAsync(selected);
        // apply update to server when new feature is deleted
        tableResult.addDoneListener(() -> applyEdits(featureTable));
      });
    } else {
      displayMessage(null, "Cannot delete attachment");
    }
  }

  /**
   * Sends any edits on the ServiceFeatureTable to the server.
   *
   * @param featureTable service feature table
   */
  private void applyEdits(ServiceFeatureTable featureTable) {

    // apply the changes to the server
    ListenableFuture<List<FeatureEditResult>> editResult = featureTable.applyEditsAsync();
    editResult.addDoneListener(() -> {
      try {
        List<FeatureEditResult> edits = editResult.get();
        // check if the server edit was successful
        if (edits != null && edits.size() > 0) {
          if (!edits.get(0).hasCompletedWithErrors()) {
            displayMessage(null, "Edited feature successfully");
          } else {
            throw edits.get(0).getError();
          }
        }
        // update the displayed list of attachments
        fetchAttachments(selected);
      } catch (InterruptedException | ExecutionException e) {
        displayMessage("Error applying edits on server ", e.getCause().getMessage());
      }
    });
  }

  /**
   * Shows a message in an alert dialog.
   *
   * @param title title of alert
   * @param message message to display
   */
  private void displayMessage(String title, String message) {

    Platform.runLater(() -> {
      Alert dialog = new Alert(Alert.AlertType.INFORMATION);
      dialog.setHeaderText(title);
      dialog.setContentText(message);
      dialog.showAndWait();
    });
  }

  /**
   * Stops and releases all resources used in application.
   */
  @Override
  public void stop() {

    // release resources when the application closes
    if (mapView != null) {
      mapView.dispose();
    }
  }

  /**
   * Opens and runs application.
   * 
   * @param args arguments passed to this application
   */
  public static void main(String[] args) {

    Application.launch(args);
  }

}


In this topic
  1. How it works
  2. Code