develop/leaflet/query_with_html5_location/index.html

<html>
<head>
  <meta charset=utf-8 />
  <title>Use html5 geolocation to query</title>
  <meta name='viewport' content='initial-scale=1,maximum-scale=1,user-scalable=no' />

  <!-- Load Leaflet from CDN-->
  <link rel="stylesheet" href="https://unpkg.com/leaflet@1.0.1/dist/leaflet.css" />
  <script src="https://unpkg.com/leaflet@1.0.1/dist/leaflet-src.js"></script>

  <!-- Load Esri Leaflet from CDN -->
  <script src="https://unpkg.com/esri-leaflet@2.0.4"></script>

  <style>
    body { margin:0; padding:0; }
    #mapDiv { position: absolute; top:0; bottom:0; right:0; left:0; }
  </style>
</head>
<body>

<div id="mapDiv"></div>

<script>

  // html5 geolocation requires a secure connection
  if (window.location.hostname != 'localhost' && window.location.protocol != "https:") {
    window.location.protocol = "https";
  }

  var map = L.map('mapDiv').setView([34, -118], 10);
  L.esri.basemapLayer('DarkGray').addTo(map);

  // ask leaflet to use HTML5 to query the user location
  map.locate();

  // listen for the result of that asynchronous method
  map.on('locationfound', function(evt) {
    // construct a query object
    var censusBlocks = L.esri.query({
      url: 'https://sampleserver6.arcgisonline.com/arcgis/rest/services/Census/MapServer/1'
    });
    // pass it the user's current location
    censusBlocks.intersects(evt.latlng);
    // execute the spatial query
    censusBlocks.run(function(error, intersectingBlocks){
      // add the GeoJson to the map
      var blockLayer = L.geoJSON(intersectingBlocks).addTo(map);
      // and update the map extent
      map.fitBounds(blockLayer.getBounds())
    });
  });
</script>

</body>
</html>