Find the service areas of several facilities from a feature service.
Use case
A city taxi company may calculate service areas around their vehicle lots to identify gaps in coverage. Alternatively, they may want to ensure overlaps where a high volume of passengers requires redundant facilities, such as near an airport.
How to use the sample
Click 'Find service areas' to calculate and display the service area of each facility (hospital) on the map. The polygons displayed around each facility represent the facility's service area: the red area is within 1 minute travel time from the hospital by car, whilst orange is within 3 minutes by car. All service areas are semi-transparent to show where they overlap.
How it works
Create a new ServiceAreaTask from a network service.
Create default ServiceAreaParameters from the service area task.
Set the parameters ServiceAreaParameters.returnPolygons = true to return polygons of all service areas.
Define QueryParameters that retrieve all Facility items from a ServiceFeatureTable. Add the facilities to the service area parameters using the query parameters, serviceAreaParameters.SetFacilitiesWithFeatureTable(facilitiesTable, queryParameters).
Get the ServiceAreaResult by solving the service area task using the parameters.
For each facility, get any ServiceAreaPolygons that were returned, serviceAreaResult.resultPolygons(facilityIndex).
Display the service area polygons as Graphics in a GraphicsOverlay on the MapView.
Relevant API
ServiceAreaParameters
ServiceAreaPolygon
ServiceAreaResult
ServiceAreaTask
About the data
This sample uses a street map of San Diego, in combination with a feature service with facilities (used here to represent hospitals). Additionally a street network is used on the server for calculating the service area.
Tags
facilities, feature service, impedance, network analysis, service area, travel time
Sample Code
FindServiceAreasForMultipleFacilities.qml
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// [WriteFile Name=FindServiceAreasForMultipleFacilities, Category=Routing]// [Legal]// Copyright 2020 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.// [Legal]import QtQuick
import Esri.ArcGISRuntime
import QtQuick.Layouts
import QtQuick.Controls
Rectangle {
id: rootRectangleclip: truewidth: 800height: 600property url featureTableUrl: "https://services2.arcgis.com/ZQgQTuoyBrtmoGdP/ArcGIS/rest/services/San_Diego_Facilities/FeatureServer/0"property url imageUrl: "https://static.arcgis.com/images/Symbols/SafetyHealth/Hospital.png"property url serviceTaskAreaUrl: "https://sampleserver6.arcgisonline.com/arcgis/rest/services/NetworkAnalysis/SanDiego/NAServer/ServiceArea"property list<SimpleFillSymbol> fillSymbols: [
SimpleFillSymbol {
style: Enums.SimpleFillSymbolStyleSolid
color: "#66FFA500"outline: null },
SimpleFillSymbol {
style: Enums.SimpleFillSymbolStyleSolid
color: "#66FF0000" }
]
MapView {
id: mapViewanchors.fill: parentComponent.onCompleted: {
// Set the focus on MapView to initially enable keyboard navigation forceActiveFocus();
}
GraphicsOverlay {
id: serviceAreasOverlay }
Map {
Basemap {
initStyle: Enums.BasemapStyleArcGISLightGray
}
// create query parameters used to select all facilities from the feature tableQueryParameters {
id: queryParameterswhereClause: "1=1" }
FeatureLayer {
featureTable: ServiceFeatureTable {
id: featureTableurl: featureTableUrl
}
onLoadStatusChanged: {
if(loadStatus === Enums.LoadStatusLoaded) {
mapView.setViewpointGeometryAndPadding(fullExtent, 100);
}
}
onErrorChanged: {
console.warn(error.message);
}
renderer: SimpleRenderer {
PictureMarkerSymbol {
url: imageUrl
height: 25width: 25 }
}
}
ServiceAreaTask {
id: serviceAreaTaskurl: serviceTaskAreaUrl
Component.onCompleted: {
load();
}
onErrorChanged: {
console.warn(error.message);
}
onLoadStatusChanged: {
if (loadStatus === Enums.LoadStatusLoaded) {
createDefaultParameters();
}
}
onCreateDefaultParametersStatusChanged: {
if (createDefaultParametersStatus === Enums.TaskStatusCompleted) {
createDefaultParametersResult.polygonDetail = Enums.ServiceAreaPolygonDetailHigh;
createDefaultParametersResult.returnPolygons = true;
// add service areas of 1 minute and 3 minutes travel time by car createDefaultParametersResult.defaultImpedanceCutoffs = [1.0, 3.0];
createDefaultParametersResult.setFacilitiesWithFeatureTable(featureTable, queryParameters);
}
}
onSolveServiceAreaStatusChanged: {
if (solveServiceAreaStatus === Enums.TaskStatusCompleted) {
// iterate through the facilities to get the service area polygonsfor (let i = 0; i < solveServiceAreaResult.facilities.length; i++) {
const serviceAreaPolygonList = solveServiceAreaResult.resultPolygons(i);
//create a graphic for each available polygonfor (let j = 0; j < serviceAreaPolygonList.length; j++) {
serviceAreasOverlay.graphics.append(ArcGISRuntimeEnvironment.createObject("Graphic", {geometry: serviceAreaPolygonList[j].geometry, symbol: fillSymbols[j]}));
}
}
}
}
}
}
RowLayout {
anchors {
left: parent.left
top: parent.top
}
Button {
Layout.fillWidth: trueLayout.fillHeight: truetext: "Find service areas"onClicked: {
enabled = false;
serviceAreaTask.solveServiceArea(serviceAreaTask.createDefaultParametersResult)
}
}
}
}
BusyIndicator {
anchors.centerIn: parentvisible: truerunning: serviceAreaTask.solveServiceAreaStatus === Enums.TaskStatusInProgress
}
}