Add feature layers

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 // Copyright 2022 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 // // https://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.  import ArcGIS import SwiftUI  struct AddFeatureLayersView: View {  /// The error shown in the error alert.  @State private var error: Error?   /// The current viewpoint of the map view.  @State private var viewpoint: Viewpoint?   /// The view model for the sample.  @StateObject private var model = Model()   var body: some View {  MapView(map: model.map, viewpoint: viewpoint)  .onViewpointChanged(kind: .centerAndScale) { viewpoint = $0 }  .toolbar {  ToolbarItem(placement: .bottomBar) {  Picker("Feature Layer", selection: $model.selectedFeatureLayerSource) {  ForEach(FeatureLayerSource.allCases, id: \.self) { source in  Text(source.label)  }  }  .task(id: model.selectedFeatureLayerSource) {  do {  // Loads the selected feature layer.  try await model.updateFeatureLayer()  viewpoint = model.featureLayerViewpoint  } catch {  // Updates the error and shows an alert if any failures occur.  self.error = error  }  }  }  }  .errorAlert(presentingError: $error)  .onAppear {  // Updates the URL session challenge handler to use the  // specified credentials and tokens for any challenges.  ArcGISEnvironment.authenticationManager.arcGISAuthenticationChallengeHandler = ChallengeHandler()  }  .onTeardown {  // Resets the URL session challenge handler to use default handling  // and removes all credentials.  ArcGISEnvironment.authenticationManager.arcGISAuthenticationChallengeHandler = nil  ArcGISEnvironment.authenticationManager.arcGISCredentialStore.removeAll()  }  } }  /// The authentication model used to handle challenges and credentials. private struct ChallengeHandler: ArcGISAuthenticationChallengeHandler {  func handleArcGISAuthenticationChallenge(  _ challenge: ArcGISAuthenticationChallenge  ) async throws -> ArcGISAuthenticationChallenge.Disposition {  // NOTE: Never hardcode login information in a production application.  // This is done solely for the sake of the sample.  return .continueWithCredential(  try await TokenCredential.credential(for: challenge, username: "viewer01", password: "I68VGU^nMurF")  )  } }  private extension AddFeatureLayersView {  /// The model used to store the geo model and other expensive objects  /// used in this view.  @MainActor  class Model: ObservableObject {  /// A map with a topographic basemap style.  let map = Map(basemapStyle: .arcGISTopographic)   /// The geodatabase used to create the feature layer.  private var geodatabase: Geodatabase!   /// The GeoPackage used to create the feature layer.  private var geoPackage: GeoPackage!   /// The viewpoint for a specific feature layer.  var featureLayerViewpoint: Viewpoint?   /// The feature layer source that is displayed.  @Published var selectedFeatureLayerSource: FeatureLayerSource = .serviceFeatureTable   /// Loads a feature layer with a service feature table.  private func loadServiceFeatureTable() async throws {  // Creates a service feature table from a feature service.  let featureTable = ServiceFeatureTable(url: .damageAssessment)  try await featureTable.load()  let featureLayer = FeatureLayer(featureTable: featureTable)  setFeatureLayer(featureLayer, viewpoint: .napervilleIL)  }   /// Loads a feature layer with a portal item.  private func loadPortalItemFeatureTable() async throws {  let portalItem = PortalItem(  portal: .arcGISOnline(connection: .anonymous),  id: .treesOfPortland  )  try await portalItem.load()  let featureLayer = FeatureLayer(item: portalItem)  setFeatureLayer(featureLayer, viewpoint: .portlandOR)  }   /// Loads a feature layer with a local geodatabase.  private func loadGeodatabaseFeatureTable() async throws {  // Loads the geodatabase if it does not exist.  if geodatabase == nil {  geodatabase = Geodatabase(fileURL: .laTrails)  try await geodatabase.load()  }  // Creates a feature layer from the geodatabase's feature table and  // sets the current feature layer to it.  let featureTable = geodatabase.featureTable(named: "Trailheads")!  let featureLayer = FeatureLayer(featureTable: featureTable)  setFeatureLayer(featureLayer, viewpoint: .losAngelesCA)  }   /// Loads a feature layer with a local GeoPackage.  private func loadGeoPackageFeatureTable() async throws {  // Loads the GeoPackage if it does not exist.  if geoPackage == nil {  geoPackage = GeoPackage(fileURL: .auroraCO)  try await geoPackage.load()  }  // Creates a feature layer from the GeoPackage's feature tables and  // sets the current feature layer to the first one.  let featureTable = geoPackage.featureTables.first!  let featureLayer = FeatureLayer(featureTable: featureTable)  setFeatureLayer(featureLayer, viewpoint: .auroraCO)  }   /// Loads a feature layer with a local shapefile.  private func loadShapefileFeatureTable() async throws {  let shapefileFeatureTable = ShapefileFeatureTable(fileURL: .reserveBoundaries)  try await shapefileFeatureTable.load()  let featureLayer = FeatureLayer(featureTable: shapefileFeatureTable)  setFeatureLayer(featureLayer, viewpoint: .scotland)  }   /// Sets the map's operational layers to the given feature layer and updates the current viewpoint.  private func setFeatureLayer(_ featureLayer: FeatureLayer, viewpoint: Viewpoint) {  // Updates the map's operational layers.  map.removeAllOperationalLayers()  map.addOperationalLayer(featureLayer)  // Updates the current viewpoint.  featureLayerViewpoint = viewpoint  }   /// Updates the feature layer to reflect the source chosen by the user.  func updateFeatureLayer() async throws {  switch selectedFeatureLayerSource {  case .serviceFeatureTable:  try await loadServiceFeatureTable()  case .portalItem:  try await loadPortalItemFeatureTable()  case .geodatabase:  try await loadGeodatabaseFeatureTable()  case .geoPackage:  try await loadGeoPackageFeatureTable()  case .shapefile:  try await loadShapefileFeatureTable()  }  }  } }  private extension AddFeatureLayersView {  /// The various feature layer sources for the sample.  enum FeatureLayerSource: CaseIterable, Equatable {  case shapefile, geoPackage, geodatabase, portalItem, serviceFeatureTable   /// A human-readable label for each feature layer source.  var label: String {  switch self {  case .serviceFeatureTable: return "Service Feature Table"  case .portalItem: return "Portal Item"  case .geodatabase: return "Mobile Geodatabase"  case .geoPackage: return "GeoPackage"  case .shapefile: return "Shapefile"  }  }  } }  private extension Viewpoint {  /// The viewpoint for Naperville, IL.  static var napervilleIL: Viewpoint {  Viewpoint(latitude: 41.7735, longitude: -88.1431, scale: 4e3)  }   /// The viewpoint for Portland, OR.  static var portlandOR: Viewpoint {  Viewpoint(latitude: 45.5266, longitude: -122.6219, scale: 6e3)  }   /// The viewpoint for Los Angeles, CA.  static var losAngelesCA: Viewpoint {  Viewpoint(latitude: 34.0772, longitude: -118.7989, scale: 6e5)  }   /// The viewpoint for Aurora, CO.  static var auroraCO: Viewpoint {  Viewpoint(latitude: 39.7294, longitude: -104.8319, scale: 5e5)  }   /// The viewpoint for Scotland.  static var scotland: Viewpoint {  Viewpoint(latitude: 56.6413, longitude: -3.8890, scale: 6e6)  } }  private extension PortalItem.ID {  /// The ID used in the "Trees of Portland" portal item.  static var treesOfPortland: Self { Self("1759fd3e8a324358a0c58d9a687a8578")! } }  private extension URL {  /// Naperville damage assessment service.  static var damageAssessment: URL { .init(string: "https://sampleserver7.arcgisonline.com/server/rest/services/DamageAssessment/FeatureServer/0")! }   /// Los Angeles Trailheads geodatabase.  static var laTrails: URL { Bundle.main.url(forResource: "LA_Trails", withExtension: "geodatabase")! }   /// Aurora, Colorado GeoPackage.  static var auroraCO: URL { Bundle.main.url(forResource: "AuroraCO", withExtension: "gpkg")! }   /// Scottish Wildlife Trust Reserves Shapefile.  static var reserveBoundaries: URL { Bundle.main.url(forResource: "ScottishWildlifeTrust_ReserveBoundaries_20201102", withExtension: "shp", subdirectory: "ScottishWildlifeTrust_reserves")! } }