Offline routing

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Sample viewer app

Solve a route on-the-fly using offline data.

Fastest route Shortest route

Use case

You can use an offline network to enable routing in disconnected scenarios. For example, you could provide offline location capabilities to field workers repairing critical infrastructure in a disaster when network availability is limited.

How to use the sample

Tap near a road to start adding a stop to the route, tap again to place it on the map. A number graphic will show its order in the route. After adding at least 2 stops, a route will display. Choose "Fastest" or "Shortest" to control how the route is optimized. The route will update on-the-fly while adding stops.

How it works

Create the map's AGSBasemap from a local tile package using an AGSTileCache and AGSArcGISTiledLayer.
Create an AGSRouteTask with an offline locator geodatabase.
Generate default AGSRouteParameters using AGSRouteTask.defaultRouteParameters(completion:).
Create an ASGStop object for each destination and assign the stops to the parameters using AGSRouteParameters.setStops(_:).
Solve the route using AGSRouteTask.solveRoute(with:completion:) to get an AGSRouteResult.
Create a graphic with the route's geometry and a AGSSimpleLineSymbol and display it on another AGSGraphicsOverlay.

Relevant API

AGSRouteParameters
AGSRouteResult
AGSRouteTask
AGSStop
AGSTravelMode

Offline data

The data used by this sample is available on ArcGIS Online.

About the data

This sample uses a pre-packaged sample dataset consisting of a geodatabase with a San Diego road network and a tile package with a streets basemap.

Sample Code

OfflineRoutingViewController.swift
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// Copyright 2016 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.

import UIKit
import ArcGIS

class OfflineRoutingViewController: UIViewController, AGSGeoViewTouchDelegate {
    @IBOutlet var mapView: AGSMapView!
    @IBOutlet var segmentedControl: UISegmentedControl!
    @IBOutlet var distanceLabel: UILabel!
    @IBOutlet var timeLabel: UILabel!
    @IBOutlet var detailsViewBottomContraint: NSLayoutConstraint!

    var map: AGSMap!
    var routeTask: AGSRouteTask!
    var params: AGSRouteParameters!

    private var stopGraphicsOverlay = AGSGraphicsOverlay()
    private var routeGraphicsOverlay = AGSGraphicsOverlay()
    private var longPressedGraphic: AGSGraphic!
    private var longPressedRouteGraphic: AGSGraphic!
    private var routeTaskOperation: AGSCancelable!

    private var totalDistance: Double = 0 {
        didSet {
            let miles = String(format: "%.2f", totalDistance * 0.000621371)
            self.distanceLabel?.text = "(\(miles) mi)"
        }
    }
    private var totalTime: Double = 0 {
        didSet {
            var minutes = Int(totalTime)
            let hours = minutes / 60
            minutes = minutes % 60
            let hoursString = hours == 0 ? "" : "\(hours) hr "
            let minutesString = minutes == 0 ? "0 min" : "\(minutes) min"
            self.timeLabel?.text = "\(hoursString)\(minutesString)"
        }
    }

    override func viewDidLoad() {
        super.viewDidLoad()

        // add the source code button item to the right of navigation bar
        (self.navigationItem.rightBarButtonItem as! SourceCodeBarButtonItem).filenames = ["OfflineRoutingViewController"]

        // using a tpk to create a local tiled layer
        // which will be visible in case of no network connection
        let tileCache = AGSTileCache(name: "streetmap_SD")
        let localTiledLayer = AGSArcGISTiledLayer(tileCache: tileCache)

        // initialize the map using the local tiled layer as baselayer
        self.map = AGSMap(basemap: AGSBasemap(baseLayer: localTiledLayer))

        // assign the map to the map view
        self.mapView.map = self.map

        // register self as the touch delegate for the map view
        // will be using the touch gestures to add the stops
        self.mapView.touchDelegate = self

        // add graphics overlay, one for the stop graphics
        // and other for the route graphics
        self.mapView.graphicsOverlays.addObjects(from: [self.routeGraphicsOverlay, self.stopGraphicsOverlay])

        // get the path for the geodatabase in the bundle
        let dbPath = Bundle.main.path(forResource: "sandiego", ofType: "geodatabase", inDirectory: "san-diego")!

        // initialize the route task using the path and the network name
        self.routeTask = AGSRouteTask(fileURLToDatabase: URL(fileURLWithPath: dbPath), networkName: "Streets_ND")

        // get default route parameters
        self.getDefaultParameters()

        // zoom to San Diego
        self.mapView.setViewpointCenter(AGSPoint(x: -13042254.715252, y: 3857970.236806, spatialReference: .webMercator()), scale: 2e4)

        // enable magnifier for better experience while using tap n hold to add a stop
        self.mapView.interactionOptions.isMagnifierEnabled = true
    }

    // method returns a graphic for the specified location
    // also assigns the stop number
    private func graphicForLocation(_ point: AGSPoint) -> AGSGraphic {
        let symbol = self.symbolForStopGraphic(withIndex: self.stopGraphicsOverlay.graphics.count + 1)
        let graphic = AGSGraphic(geometry: point, symbol: symbol, attributes: nil)
        return graphic
    }

    private func symbolForStopGraphic(withIndex index: Int) -> AGSSymbol {
        let markerImage = UIImage(named: "BlueMarker")!
        let markerSymbol = AGSPictureMarkerSymbol(image: markerImage)
        markerSymbol.offsetY = markerImage.size.height / 2

        let textSymbol = AGSTextSymbol(text: "\(index)", color: .white, size: 20, horizontalAlignment: .center, verticalAlignment: .middle)
        textSymbol.offsetY = markerSymbol.offsetY

        let compositeSymbol = AGSCompositeSymbol(symbols: [markerSymbol, textSymbol])

        return compositeSymbol
    }

    // MARK: - AGSGeoViewTouchDelegate

    func geoView(_ geoView: AGSGeoView, didTapAtScreenPoint screenPoint: CGPoint, mapPoint: AGSPoint) {
        // on single tap, add stop graphic at the tapped location
        // and route
        let graphic = self.graphicForLocation(mapPoint)
        self.stopGraphicsOverlay.graphics.add(graphic)

        // clear the route graphic
        self.longPressedRouteGraphic = nil

        self.route(isLongPressed: false)
    }

    func geoView(_ geoView: AGSGeoView, didLongPressAtScreenPoint screenPoint: CGPoint, mapPoint: AGSPoint) {
        // add the graphic at that point
        // keep a reference to that graphic to update the geometry if moved
        let graphic = graphicForLocation(mapPoint)
        self.stopGraphicsOverlay.graphics.add(graphic)
        self.longPressedGraphic = graphic
        // clear the route graphic
        self.longPressedRouteGraphic = nil
        // route
        self.route(isLongPressed: true)
    }

    func geoView(_ geoView: AGSGeoView, didMoveLongPressToScreenPoint screenPoint: CGPoint, mapPoint: AGSPoint) {
        // update the graphic
        // route
        self.longPressedGraphic.geometry = mapPoint
        self.route(isLongPressed: true)
    }

    // MARK: - Route logic

    private func getDefaultParameters() {
        // get the default parameters
        self.routeTask.defaultRouteParameters { [weak self] (params: AGSRouteParameters?, error: Error?) in
            if let error = error {
                print(error)
            } else {
                self?.params = params
            }
        }
    }

    func route(isLongPressed: Bool) {
        // if either default parameters failed to generate or
        // the number of stops is less than two, return
        if self.params == nil {
            print("Failed to generate default parameters")
            return
        }
        if self.stopGraphicsOverlay.graphics.count < 2 {
            print("The stop count is less than 2")
            return
        }

        // cancel previous requests
        self.routeTaskOperation?.cancel()
        self.routeTaskOperation = nil

        // get the geometries for the last two graphics in the overlay
        let count = self.stopGraphicsOverlay.graphics.count

        guard let geometry1 = (self.stopGraphicsOverlay.graphics[count - 2] as? AGSGraphic)?.geometry as? AGSPoint else {
            print("Graphic's geometry is invalid")
            return
        }

        guard let geometry2 = (self.stopGraphicsOverlay.graphics[count - 1] as? AGSGraphic)?.geometry as? AGSPoint else {
            print("Graphic's geometry is invalid")
            return
        }

        // create stops using the last two graphics in the overlay
        let stop1 = AGSStop(point: (geometry1))
        let stop2 = AGSStop(point: (geometry2))
        let stops = [stop1, stop2]

        // clear the previous stops
        self.params.clearStops()
        // add the new stops
        self.params.setStops(stops)

        // set the new travel mode
        self.params.travelMode = self.routeTask.routeTaskInfo().travelModes[self.segmentedControl.selectedSegmentIndex]

        self.route(with: self.params, isLongPressed: isLongPressed)
    }

    func route(with params: AGSRouteParameters, isLongPressed: Bool) {
        // solve for route
        self.routeTaskOperation = self.routeTask.solveRoute(with: params) { [weak self] (routeResult: AGSRouteResult?, error: Error?) in
            if let error = error {
                if (error as NSError).code != NSUserCancelledError {
                    print(error)
                }
            } else {
                // handle the route result
                self?.displayRoutesOnMap(routeResult?.routes, isLongPressedResult: isLongPressed)
            }
        }
    }

    func displayRoutesOnMap(_ routes: [AGSRoute]?, isLongPressedResult: Bool) {
        // if a route graphic for previous request (in case of long press)
        // exists then remove it
        if let longPressedRouteGraphic = longPressedRouteGraphic {
            // update distance and time
            self.totalTime -= Double(truncating: self.longPressedGraphic.attributes["routeTime"] as! NSNumber)
            self.totalDistance -= Double(truncating: self.longPressedGraphic.attributes["routeLength"] as! NSNumber)

            self.routeGraphicsOverlay.graphics.remove(longPressedRouteGraphic)
            self.longPressedRouteGraphic = nil
        }

        // if a route is returned, create a graphic for it
        // and add to the route graphics overlay
        if let route = routes?.first {
            let routeGraphic = AGSGraphic(geometry: route.routeGeometry, symbol: self.routeSymbol(), attributes: nil)
            // keep reference to the graphic in case of long press
            // to remove in case of cancel or move
            if isLongPressedResult {
                self.longPressedRouteGraphic = routeGraphic

                // set attributes (to subtract in case the route is not used)
                self.longPressedGraphic.attributes["routeTime"] = route.totalTime
                self.longPressedGraphic.attributes["routeLength"] = route.totalLength
            }
            self.routeGraphicsOverlay.graphics.add(routeGraphic)

            // update total distance and total time
            self.totalTime += route.totalTime
            self.totalDistance += route.totalLength

            self.setDetailsViewVisibility(visible: true)
        }
    }

    // method returns the symbol for the route graphic
    func routeSymbol() -> AGSSimpleLineSymbol {
        let symbol = AGSSimpleLineSymbol(style: .solid, color: .yellow, width: 5)
        return symbol
    }

    // MARK: - Actions

    @IBAction func trashAction() {
        // empty both graphic overlays
        self.routeGraphicsOverlay.graphics.removeAllObjects()
        self.stopGraphicsOverlay.graphics.removeAllObjects()

        // reset distance and time
        self.totalTime = 0
        self.totalDistance = 0

        // hide the details view
        self.setDetailsViewVisibility(visible: false)
    }

    @IBAction func modeChanged(_ segmentedControl: UISegmentedControl) {
        // re route for already added stops
        if self.stopGraphicsOverlay.graphics.count > 1 {
            var stops = [AGSStop]()
            for graphic in self.stopGraphicsOverlay.graphics as AnyObject as! [AGSGraphic] {
                let stop = AGSStop(point: graphic.geometry! as! AGSPoint)
                stops.append(stop)
            }

            self.params.clearStops()
            self.params.setStops(stops)

            // set the new travel mode
            self.params.travelMode = self.routeTask.routeTaskInfo().travelModes[self.segmentedControl.selectedSegmentIndex]

            // clear all previous routes
            self.routeGraphicsOverlay.graphics.removeAllObjects()

            // reset distance and time
            self.totalDistance = 0
            self.totalTime = 0

            // route
            self.route(with: self.params, isLongPressed: false)
        }
    }

    // MARK: toggle details view

    private func setDetailsViewVisibility(visible: Bool) {
        self.detailsViewBottomContraint.constant = visible ? 0 : -36

        UIView.animate(withDuration: 0.3) { [weak self] in
            self?.view.layoutIfNeeded()
        }
    }
}