AzureMapsCodeSamples/Samples/Spatial Math/Get closest HTML marker to position/Get closest HTML marker to position.html at main · Azure-Samples/AzureMapsCodeSamples · GitHub

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<!DOCTYPE html>
<html lang="en">
<head>
    <title>Get closest HTML marker to position - Azure Maps Web SDK Samples</title>

    <meta charset="utf-8" />
	<link rel="shortcut icon" href="/favicon.ico"/>

    <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no" />
    <meta name="description" content="This sample shows how to calculate the closest marker to a given position, in this case, where the user clicked on the map." />
    <meta name="keywords" content="Microsoft maps, map, gis, API, SDK, geospatial, spatial math, math, markers, coordinate" />
    <meta name="author" content="Microsoft Azure Maps" /><meta name="version" content="1.0" />
    <meta name="screenshot" content="screenshot.jpg" />

    <!-- Add references to the Azure Maps Map control JavaScript and CSS files. -->
    <link href="https://atlas.microsoft.com/sdk/javascript/mapcontrol/3/atlas.min.css" rel="stylesheet" />
    <script src="https://atlas.microsoft.com/sdk/javascript/mapcontrol/3/atlas.min.js"></script>

    <script>
        var map, closestMarker;

        function getMap() {
            //Initialize a map instance.
            map = new atlas.Map('myMap', {
                view: 'Auto',
                language: 'Auto',

                //Add authentication details for connecting to Azure Maps.
                authOptions: {
                    // Use SAS token for authentication
                    authType: 'sas',
                    getToken: function (resolve, reject, map) {
                        // URL to your authentication service that retrieves a SAS Token
                        var tokenServiceUrl = 'https://samples.azuremaps.com/api/GetAzureMapsSasToken';

                        fetch(tokenServiceUrl).then(r => r.text()).then(token => resolve(token));
                    }

                    //Alternatively, use an Azure Maps key. Get an Azure Maps key at https://azure.com/maps. NOTE: The primary key should be used as the key.
                    //authType: 'subscriptionKey',
                    //subscriptionKey: '[YOUR_AZURE_MAPS_KEY]'
                }
            });

            //Wait until the map resources are ready.
            map.events.add('ready', function () {

                //Generate some random markers.
                generateRandomMarkers();

                //Add a click event to the map.
                map.events.add('click', getClosestMarker);
            });
        }

        function getClosestMarker(e) {
            //Reset the color of any previously closest point.
            if (closestMarker) {
                closestMarker.setOptions({ color: 'blue' });
                closestMarker = null;
                document.getElementById('infoPanel').innerHTML = '';
            }

            var markers = map.markers.getMarkers();
            var minDistance = Infinity;

            for (var i = 0; i < markers.length; i++) {
                //Calculate the distance between marker and the position.
                var d = atlas.math.getDistanceTo(markers[i].getOptions().position, e.position, 'miles');

                if (d < minDistance) {
                    closestMarker = markers[i];
                    minDistance = d;
                }
            }

            if (closestMarker) {
                closestMarker.setOptions({ color: 'red' });

                //Display details about closest point.
                document.getElementById('infoPanel').innerHTML = ` - Marker Id: ${closestMarker.properties.id}<br/> - Distance: ${Math.round(minDistance)} miles`;
            }
        }

        function generateRandomMarkers() {
            var markers = [];

            for (var i = 0; i < 100; i++) {
                var m = new atlas.HtmlMarker({
                    position: [Math.random() * 360 - 180, Math.random() * 170 - 85],
                    color: 'blue'
                });

                //Attach custom properites to the marker.
                m.properties = {
                    id: i
                };

                markers.push(m);
            }

            map.markers.add(markers);
        }
    </script>
</head>
<body onload="getMap()">
    <div id="myMap" style="position:relative;width:100%;min-width:290px;height:600px;"></div>

    <div style="position:absolute;top:10px;left:10px;background-color:#fff;padding:10px;border-radius:20px;">
        Click on the map to find the closest marker. <br /><br />
        Closest marker:<br /><br />
        <span id="infoPanel"></span>
    </div>

    <fieldset style="width:calc(100% - 30px);min-width:290px;margin-top:10px;">
        <legend>Get closest HTML marker to position</legend>
        This sample shows how to calculate the closest marker to a given position, in this case, where the user clicked on the map.
        The closest marker will have it's color changed to red.
        This is achieved by looping over through the data and calculating the distance between the position and each marker using the atlas.math.getDistanceTo function.
    </fieldset>
</body>
</html>