Run a geoprocessing task to calculate routes to hospitals using the Esri Leaflet GP plugin. To learn more about routing, go to the Find a route and directions tutorial.
<html>
<head>
<meta charset="utf-8" />
<title>Run a geoprocessing task</title>
<meta name="viewport" content="initial-scale=1, maximum-scale=1, user-scalable=no" />
<link rel="stylesheet" href="https://unpkg.com/leaflet@1.9.4/dist/leaflet.css" crossorigin="" />
<script src="https://unpkg.com/leaflet@1.9.4/dist/leaflet.js" crossorigin=""></script>
<!-- Load Esri Leaflet from CDN -->
<script src="https://unpkg.com/esri-leaflet@3.0.10/dist/esri-leaflet.js"></script>
<!-- Load Esri Leaflet Vector from CDN -->
<script src="https://unpkg.com/esri-leaflet-vector@4.2.2/dist/esri-leaflet-vector.js" crossorigin=""></script>
<!-- Load Esri Leaflet GP from CDN -->
<script src="https://unpkg.com/esri-leaflet-gp@3.0.0/dist/esri-leaflet-gp.js"></script>
<style>
html,
body,
#map {
padding: 0;
margin: 0;
height: 100%;
width: 100%;
font-family: Arial, Helvetica, sans-serif;
font-size: 14px;
color: #323232;
}
#info-pane {
position: absolute;
top: 10px;
right: 10px;
z-index: 1000;
padding: 1em;
background: white;
}
</style>
</head>
<body>
<div id="map"></div>
<div id="info-pane" class="leaflet-bar">
<label>
Click on the map to calculate the best route to the nearest hospital.
</label>
</div>
<script>
let map = L.map('map').setView([33.780021258266224, -118.18885803222658], 12);
const apiKey = "YOUR_API_KEY";
const basemapEnum = "arcgis/light-gray";
L.esri.Vector.vectorBasemapLayer(basemapEnum, {
apiKey: apiKey
}).addTo(map);
// layers to organize graphics
let routesLayer = L.featureGroup();
let ambulanceLayer = L.featureGroup();
map.addLayer(routesLayer);
map.addLayer(ambulanceLayer);
let ambulanceIcon = L.icon({
iconUrl: 'https://cdn1.iconfinder.com/data/icons/covid-19-74/32/ambulance_car_covid-19-512.png',
iconSize: [40, 40],
iconAnchor: [20, 20]
});
let hospitalIcon = L.icon({
iconUrl:"https://cdn3.iconfinder.com/data/icons/clinical-3/96/medical-kit-512.png",
iconSize: [40, 40],
iconAnchor: [20, 20]
})
// use a service proxy to authenticate automagically
// https://developers.arcgis.com/authentication/working-with-proxies/
let closestFacilityService = L.esri.GP.service({
url: "https://utility.arcgis.com/usrsvcs/appservices/FnVYYTap8ykTDC1m/rest/services/World/ClosestFacility/NAServer/ClosestFacility_World",
path: 'solveClosestFacility'
});
let closestFacilityTask = closestFacilityService.createTask();
// tell the solver we'll be driving an ambulance
closestFacilityTask.setParam("restrictionAttributeNames", "Driving an Emergency Vehicle");
closestFacilityTask.setParam("returnCFRoutes", true);
// fetch nearby hospitals from LA open data
L.esri.query({
url: "https://public.gis.lacounty.gov/public/rest/services/LACounty_Dynamic/LMS_Data_Public/MapServer/81"
})
.within(map.getBounds())
.run(function (err, response, raw) {
// draw the hospitals on the map
map.addLayer(L.geoJSON(response, {
pointToLayer: function (geoJsonPoint, latlng) {
return L.marker(latlng, {icon:hospitalIcon})
}
}));
// supply the same hospitals as an input parameter to the closest facility service
closestFacilityTask.setParam("facilities", response);
});
// when someone clicks on the map, find the route to the nearest hospital
map.on("click", function (evt) {
// clear any existing
routesLayer.clearLayers();
ambulanceLayer.clearLayers();
// add an ambulance icon to the map
ambulanceLayer.addLayer(L.marker(evt.latlng, {
icon: ambulanceIcon
}));
// supply the location of the map click as a service parameter
closestFacilityTask.setParam("incidents", evt.latlng);
// run the GP task
closestFacilityTask.run(function (err, res, raw) {
// draw the GeoJSON feature that was returned
routesLayer.addLayer(L.geoJson(res.routes.features[0], {
style: function (feature) {
return {
weight:7
}
}
}));
})
});
</script>
</body>
</html>