Google Maps - Multiple marker from extern json

Question

I have to add multiple marker to a google map, but the data is in an extern json file.

At the moment Im running it like this

var json = [
  {
    "title": "Stockholm",
    "lat": 59.3,
    "lng": 18.1,
    "description": "Stockholm is the capital and the largest city of Sweden and constitutes the most populated urban area in Scandinavia with a population of 2.1 million in the metropolitan area (2010)"
  },
  {
    "title": "Oslo",
    "lat": 59.9,
    "lng": 10.8,
    "description": "Oslo is a municipality, and the capital and most populous city of Norway with a metropolitan population of 1,442,318 (as of 2010)."
  },
  {
    "title": "Copenhagen",
    "lat": 55.7,
    "lng": 12.6,
    "description": "Copenhagen is the capital of Denmark and its most populous city, with a metropolitan population of 1,931,467 (as of 1 January 2012)."
  }
];



for (var i = 0, length = json.length; i < length; i++) {
  var data = json[i],
      latLng = new google.maps.LatLng(data.lat, data.lng); 

  // Creating a marker and putting it on the map
  var marker = new google.maps.Marker({
    position: latLng,
    map: map,
    title: data.title
  });
} 

Now im trying to exlude the Json File to an another file, but sadyl I cant get it to work ;(

Code

$.getJSON("foo.txt", function(json1) {

});


for (var i = 0, length = json.length; i < length; i++) {
  var data = json[i],
      latLng = new google.maps.LatLng(data.lat, data.lng); 

  // Creating a marker and putting it on the map
  var marker = new google.maps.Marker({
    position: latLng,
    map: map,
    title: data.title
  });
} 

foo.txt

{
    "title": "Stockholm",
    "lat": 59.3,
    "lng": 18.1,
    "description": "Stockholm is the capital and the largest city of Sweden and constitutes the most populated urban area in Scandinavia with a population of 2.1 million in the metropolitan area (2010)"
  },
  {
    "title": "Oslo",
    "lat": 59.9,
    "lng": 10.8,
    "description": "Oslo is a municipality, and the capital and most populous city of Norway with a metropolitan population of 1,442,318 (as of 2010)."
  },
  {
    "title": "Copenhagen",
    "lat": 55.7,
    "lng": 12.6,
    "description": "Copenhagen is the capital of Denmark and its most populous city, with a metropolitan population of 1,931,467 (as of 1 January 2012)."
  }

Thanks for your help

Answer 1

In the Google maps documentation you can find an example : https://developers.google.com/maps/documentation/javascript/importing_data

JQuery not needed

<div id="map"></div>
<script>
  var map;
  function initMap() {
    map = new google.maps.Map(document.getElementById('map'), {
      zoom: 2,
      center: new google.maps.LatLng(2.8,-187.3),
      mapTypeId: 'terrain'
    });

    // Create a <script> tag and set the USGS URL as the source.
    var script = document.createElement('script');
    // This example uses a local copy of the GeoJSON stored at
    // http://earthquake.usgs.gov/earthquakes/feed/v1.0/summary/2.5_week.geojsonp
    script.src = 'https://developers.google.com/maps/documentation/javascript/examples/json/earthquake_GeoJSONP.js';
    document.getElementsByTagName('head')[0].appendChild(script);
  }

  // Loop through the results array and place a marker for each
  // set of coordinates.
  window.eqfeed_callback = function(results) {
    for (var i = 0; i < results.features.length; i++) {
      var coords = results.features[i].geometry.coordinates;
      var latLng = new google.maps.LatLng(coords[1],coords[0]);
      var marker = new google.maps.Marker({
        position: latLng,
        map: map
      });
    }
  }
</script>

Answer 2

The example halex provided didn't work for me. I sorted it out by adding square brackets into foo.txt to declare it as an array and running a web server to access the html file, rather than just opening it in a browser.

I also needed to add a delay:

setTimeout(function (){marker.setMap(map);}, 1000); 

Now it works beautifully!

Answer 3

There are two problems in your code. Your json file misses the [ at the beginning and ] at the end. Your javascript is wrong too, you want to do something with the json in the callback of getJSON. The code for your problem is:

$.getJSON("foo.txt", function(json1) {
    $.each(json1, function(key, data) {
        var latLng = new google.maps.LatLng(data.lat, data.lng); 
        // Creating a marker and putting it on the map
        var marker = new google.maps.Marker({
            position: latLng,
            map: map,
            title: data.title
        });
    });
});

---

EDIT:

Here is a working example based on the google maps tutorial. You need the correct file foo.txt:

<!DOCTYPE html>
<html>
  <head>
    <meta name="viewport" content="initial-scale=1.0, user-scalable=no" />
    <style type="text/css">
      html { height: 100% }
      body { height: 100%; margin: 0; padding: 0 }
      #map_canvas { height: 100% }
    </style>
    <script type="text/javascript"
      src="http://maps.googleapis.com/maps/api/js?key=YOUR_API_KEY&sensor=true">
    </script>
    <script type="text/javascript">
      var map;
      function initialize() {
        var mapOptions = {
          center: new google.maps.LatLng(58, 16),
          zoom: 7,
          mapTypeId: google.maps.MapTypeId.ROADMAP
        };
        map = new google.maps.Map(document.getElementById("map_canvas"),
            mapOptions);
      }
    </script>
    <script type="text/javascript" src="http://code.jquery.com/jquery-latest.min.js"></script>    
  </head>
  <body onload="initialize()">
    <div id="map_canvas" style="width:100%; height:100%"></div>
    <script type="text/javascript">
      $(document).ready(function() {
        $.getJSON("foo.txt", function(json1) {
          $.each(json1, function(key, data) {
            var latLng = new google.maps.LatLng(data.lat, data.lng); 
            // Creating a marker and putting it on the map
            var marker = new google.maps.Marker({
                position: latLng,
                title: data.title
            });
            marker.setMap(map);
          });
        });
      });
    </script>
  </body>
</html>