Question

Hello 🙂 Please bear with me, I’m not a coder but I’m trying to learn by doing. This is the page I’m working on currently; http://www.websu.it/devnw/dev/contact.html.
I’ve currently set up a map using the Google Maps API, using the following javascript:

    function initialize() {

          var mapOptions = {
          zoom: 5,
          center: new google.maps.LatLng(48.160, -6.832),
          disableDefaultUI: true,
          mapTypeId: google.maps.MapTypeId.ROADMAP
          };

         map = new google.maps.Map(document.getElementById('map_canvas'), mapOptions);
             setMarkers(map, cities);
              }


 var cities = [
   ['Groningen', 53.216723950863425, 6.560211181640625, 4],
   ['San Francisco', 34.01131647557699, -118.25599389648437, 5],
   ['New York City', 40.7143528, -74.0059731, 3],
   ['Amsterdam', 52.3702157, 4.8951679, 2],
   ['Maroubra Beach', -33.950198, 151.259302, 1]
 ];

 function setMarkers(map, locations) {

   for (var i = 0; i < locations.length; i++) {
     var city = locations[i];
     var myLatLng = new google.maps.LatLng(city[1], city[2]);
     var marker = new google.maps.Marker({
         position: myLatLng,
         map: map,
         title: city[0],
         zIndex: city[3]
     });
   }
 }

 This continues below...

And then I created a list where every li element, when clicked upon, results in a panning of the map to one of these markers.

I’ve added the following code and it works very well. But it means that I have to add the longitudes/latitudes for every city in the above code array of “cities”, as well as in the code below for the var laLatLng. How can I get the lat’s and lon’s more easily in the panning script below?

      $(document).ready(function() {
      initialize();

      $("#contacts").on("click", "#sanfransisco", function() {
          var laLatLng = new google.maps.LatLng(34.01131647557699, -118.25599389648437);
          map.panTo(laLatLng);
          map.setZoom(5);
       });
      $("#contacts").on("click", "#groningen", function() {
          var laLatLng = new google.maps.LatLng(53.216723950863425, 6.560211181640625);
          map.panTo(laLatLng);
          map.setZoom(6);
      });
      $("#contacts").on("click", "#nyc", function() {
          var laLatLng = new google.maps.LatLng(40.7143528, -74.0059731);
          map.panTo(laLatLng);
          map.setZoom(6);
      });
      $("#contacts").on("click", "#losangeles", function() {
          var laLatLng = new google.maps.LatLng(52.3702157, 4.8951679);
          map.panTo(laLatLng);
          map.setZoom(6);
      });
  });

I hope someone can explain to me how to get the variables from cities into clickable list javascript. Thanks a lot, I deeply appreciate your response!

Answer 1

If you convert the cities array to an object like:

var cities = {
  'Groningen':  [ 53.216723950863425, 6.560211181640625, 4],
   'San Francisco': [ 34.01131647557699, -118.25599389648437, 5],
   'New York City': [ 40.7143528, -74.0059731, 3]

};

And add a data- attribute with matching city name along with a common class name to each of the links:

/* not sure what html looks like , using pseudo "tagName"*/
<tagName class="map_link" data-city="Groningen">Groningen</tagName>

You can create one handler for the whole class:

$("#contacts").on("click", ".map_link", function() {
          /* "this" within handler is the actual element clciked*/

          /* find correct array from "cities" object */
         var data=cities[ $(this).data('city') ]; /* returns array[ 53.21, 6.56, 4]*/
          var laLatLng = new google.maps.LatLng( data[0],  data[1]);
          map.panTo(laLatLng);
          map.setZoom( data[2]);
       });