google-mapsgoogle-geolocation

Uncaught TypeError: Cannot read property 'length' of null


I used google map javascript V3 API for this module. This code working fine untill we don't drag the map, but when i drag the map i'll get "Uncaught TypeError: Cannot read property 'length' of null "(from google chrome inspect element)

Code:

<html>
    <head>
        <title>
            Google Search
        </title>
        <style type="text/css">
            html, body { height: 100%; margin: 0; padding: 0;}
            #map-canvas { height: 80%; width:80%; margin: auto; padding: 0;}
        </style>
        <script src="js/jquery.min.js"></script>
        <script src="https://maps.googleapis.com/maps/api/js?libraries=places&sensor=false"></script>
        <script>
            var map;
            var service;

            $(document).ready(function(){
                navigator.geolocation.getCurrentPosition(initialize);
            });

            function initialize(location) {
                console.log(location);

                var currentlocation = new google.maps.LatLng(location.coords.latitude, location.coords.longitude);

                var mapOptions = {
                    center: currentlocation ,
                    zoom: 12,
                    mapTypeId: google.maps.MapTypeId.ROADMAP,
                    disableDefaultUI: true,
                    draggable: true
                };
                map = new google.maps.Map(document.getElementById("map-canvas"),
                    mapOptions);

                var marker = new google.maps.Marker({
                    position: currentlocation,
                    map: map,
                    title:"Hello World!"
                });

                service = new google.maps.places.PlacesService(map);

                google.maps.event.addListener(map, 'bounds_changed', performSearch);

                var circleOptions = {
                    strokeColor: '#FF0000',
                    strokeOpacity: 0.8,
                    strokeWeight: 2,
                    fillColor: '#FF0000',
                    fillOpacity: 0.25,
                    map: map,
                    center: currentlocation,
                    radius: 10000
                };

                var circle = new google.maps.Circle(circleOptions);

            }

            function performSearch() {
                var request = {
                    bounds: map.getBounds(),
                    name: "McDonald's"
                };

                service.nearbySearch(request, handleSearchResult);
            }

            function handleSearchResult(results, status){
                console.log(results);
                for (var i = 0; i < results.length; i++) {
                    var marker = new google.maps.Marker({
                        position: results[i].geometry.location,
                        map: map,
                        icon: "images//restaurant-71.png"
                    });
                }
            }
        </script>
    </head>
    <body>
        <div id="map-canvas"></div>
    </body>
</html>

Solution

  • You aren't checking the return status of the places search. If it encounters an error (or doesn't return any results), it will fail.

    function handleSearchResult(results, status){
      if (status == google.maps.places.PlacesServiceStatus.OK) {
        for (var i = 0; i < results.length; i++) {
          var marker = new google.maps.Marker({
              position: results[i].geometry.location,
              map: map,
              icon: "images//restaurant-71.png"
           });
         }
      } else { alert("no results"); }
    }
    

    html,
    body {
      height: 100%;
      margin: 0;
      padding: 0;
    }
    
    #map-canvas {
      height: 80%;
      width: 80%;
      margin: auto;
      padding: 0;
    }
    <html>
    
    <head>
      <title>
        Google Search
      </title>
      <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
      <script src="https://maps.googleapis.com/maps/api/js?libraries=places&key=AIzaSyCkUOdZ5y7hMm0yrcCQoCvLwzdM6M8s5qk"></script>
      <script>
        var map;
        var service;
        const successCb = (position) => {
          console.log('in success callback');
          console.log(position);
          initialize(position);
        }
    
        const errorCb = (error) => {
          console.log('in error callback');
          console.error(error);
          // allow map to be initialized
          position = {
            coords: {
              latitude: 40.7127753,
              longitude: -74.0059728
            }
          }
          initialize(position);
        }
    
    
        $(document).ready(function() {
          // navigator.geolocation.getCurrentPosition(initialize);
          navigator.geolocation.getCurrentPosition(successCb, errorCb);
        });
    
        function initialize(location) {
          console.log(location);
    
          var currentlocation = new google.maps.LatLng(location.coords.latitude, location.coords.longitude);
    
          var mapOptions = {
            center: currentlocation,
            zoom: 12,
            mapTypeId: google.maps.MapTypeId.ROADMAP,
            disableDefaultUI: true,
            draggable: true
          };
          map = new google.maps.Map(document.getElementById("map-canvas"),
            mapOptions);
    
          var marker = new google.maps.Marker({
            position: currentlocation,
            map: map,
            title: "Hello World!"
          });
    
          service = new google.maps.places.PlacesService(map);
    
          google.maps.event.addListener(map, 'bounds_changed', performSearch);
    
          var circleOptions = {
            strokeColor: '#FF0000',
            strokeOpacity: 0.8,
            strokeWeight: 2,
            fillColor: '#FF0000',
            fillOpacity: 0.25,
            map: map,
            center: currentlocation,
            radius: 10000
          };
    
          var circle = new google.maps.Circle(circleOptions);
    
        }
    
        function performSearch() {
          var request = {
            bounds: map.getBounds(),
            name: "McDonald's"
          };
    
          service.nearbySearch(request, handleSearchResult);
        }
    
        function handleSearchResult(results, status) {
          if (status == google.maps.places.PlacesServiceStatus.OK) {
            for (var i = 0; i < results.length; i++) {
              var marker = new google.maps.Marker({
                position: results[i].geometry.location,
                map: map,
                // icon: "images//restaurant-71.png" use default icon
              });
            }
          } else {
            alert("no results");
          }
        }
      </script>
    </head>
    
    <body>
      <div id="map-canvas"></div>
    </body>
    
    </html>