Adding Multiple Markers to Google Maps using json file

Question

I have a map and a JSON file containing information on Restaurants. I need to add markers to the map for 20 of the restaurants from the JSON file, but I just can't get the map to load with the markers on. I don't think i'm retrieving the data from the JSON file correctly. A point in the right direction would be greatly appreciated.

Here is my code:

  var map;
    function initialize() {
        var mapOptions = {
            center: new google.maps.LatLng(55.9753905, -1.6236163),
            zoom: 12,
            mapTypeId: google.maps.MapTypeId.ROADMAP
        };

       map = new 
         google.maps.Map(document.getElementById("EstablishmentCollection"),
           mapOptions);
           $.getJSON("'FHRS_json.json'", 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.BusinessName
               });
               marker.setMap(map);
               });
            });

And then this is sample of the start of the JSON file. There's loads of restaurants so I wont post it all.

 {
   "FHRSEstablishment": {
   "-xmlns:xsi": "http://www.w3.org/2001/XMLSchema-instance",
   "Header": {
   "ExtractDate": "2018-02-03",
   "ItemCount": "2369",
   "ReturnCode": "Success"
  },
"EstablishmentCollection": {
      "EstablishmentDetail": [
        {
          "FHRSID": "1011573",
          "LocalAuthorityBusinessID": "17/00395/MIXED",
          "BusinessName": "#Central",
          "BusinessType": "Pub/bar/nightclub",
          "BusinessTypeID": "7843",
          "AddressLine1": "15 Marlborough Crescent",
          "AddressLine2": "Newcastle upon Tyne",
          "PostCode": "NE1 4EE",
          "RatingValue": "AwaitingInspection",
          "RatingKey": "fhrs_awaitinginspection_en-GB",
          "RatingDate": { "-xsi:nil": "true" },
          "LocalAuthorityCode": "416",
          "LocalAuthorityName": "Newcastle Upon Tyne",
          "LocalAuthorityWebSite": "http://www.newcastle.gov.uk/",
          "LocalAuthorityEmailAddress": "psr@newcastle.gov.uk",
          "SchemeType": "FHRS",
          "NewRatingPending": "False",
          "Geocode": {
            "Longitude": "-1.62244200000000",
            "Latitude": "54.96785900000000"
          }
        },

Answer 1

Change your loop processing to process over the array in the JSON data:

$.each(jsonData.EstablishmentCollection.EstablishmentDetail, function(key, data) {
  var latLng = new google.maps.LatLng(data.Geocode.Latitude, data.Geocode.Longitude);
  // Creating a marker and putting it on the map
  var marker = new google.maps.Marker({
    position: latLng,
    title: data.BusinessName
  });
  marker.setMap(googleMap);
});

proof of concept fiddle

code snippet:

html,
body,
#googleMap {
  height: 100%;
  width: 100%;
  margin: 0px;
  padding: 0px
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div id="googleMap"></div>
<script>
  function initialize() {

    var center = new google.maps.LatLng(54.9753905, -1.6236163);
    var mapCanvas = document.getElementById("googleMap");
    var mapOptions = {
      center: center,
      zoom: 12
    };
    var googleMap = new google.maps.Map(mapCanvas, mapOptions);
    $.each(jsonData.EstablishmentCollection.EstablishmentDetail, function(key, data) {
      var latLng = new google.maps.LatLng(data.Geocode.Latitude, data.Geocode.Longitude);
      // Creating a marker and putting it on the map
      var marker = new google.maps.Marker({
        position: latLng,
        title: data.BusinessName
      });
      marker.setMap(googleMap);
    });
  }
</script>
<script>
  var jsonData = {
    "EstablishmentCollection": {
      "EstablishmentDetail": [{
        "FHRSID": "1011573",
        "LocalAuthorityBusinessID": "17/00395/MIXED",
        "BusinessName": "#Central",
        "BusinessType": "Pub/bar/nightclub",
        "BusinessTypeID": "7843",
        "AddressLine1": "15 Marlborough Crescent",
        "AddressLine2": "Newcastle upon Tyne",
        "PostCode": "NE1 4EE",
        "RatingValue": "AwaitingInspection",
        "RatingKey": "fhrs_awaitinginspection_en-GB",
        "RatingDate": {
          "-xsi:nil": "true"
        },
        "LocalAuthorityCode": "416",
        "LocalAuthorityName": "Newcastle Upon Tyne",
        "LocalAuthorityWebSite": "http://www.newcastle.gov.uk/",
        "LocalAuthorityEmailAddress": "psr@newcastle.gov.uk",
        "SchemeType": "FHRS",
        "NewRatingPending": "False",
        "Geocode": {
          "Longitude": "-1.62244200000000",
          "Latitude": "54.96785900000000"
        }
      }]
    }
  }
</script>
<script async defer src="https://maps.googleapis.com/maps/api/js?callback=initialize"></script>

Answer 2

Try changing the loop to:

$.each(json1.EstablishmentCollection.EstablishmentDetail, function(key, data) {

  var coords = data.Geocode;
  //look in browser console for errors and/or proper lat/lng object
  console.log(coords)


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

Answer 3

I think the main problem you're having is you need to parse the floats. Currently they are just strings. You can create a marker with the following function. Just pass the establishment as an object into the function and it will create the marker for you:

   function createMarker(obj) {
        const LatLng = new google.maps.LatLng(
            parseFloat(obj.geocode.Latitude),
            parseFloat(obj.gecode.Longitude)
        );    marker = new google.maps.Marker({
            position: LatLng,
            map: map,
            title: obj.BusinessName
        });
    }