Load google maps v3 dynamically with ajax

Found a practical way.

Fiddle here with custom event (jQuery): http://jsfiddle.net/fZqqW/94/

window.gMapsCallback = function(){
    $(window).trigger('gMapsLoaded');
}

$(document).ready((function(){
    function initialize(){
        var mapOptions = {
            zoom: 8,
            center: new google.maps.LatLng(47.3239, 5.0428),
            mapTypeId: google.maps.MapTypeId.ROADMAP
        };
        map = new google.maps.Map(document.getElementById('map_canvas'),mapOptions);
    }
    function loadGoogleMaps(){
        var script_tag = document.createElement('script');
        script_tag.setAttribute("type","text/javascript");
        script_tag.setAttribute("src","http://maps.google.com/maps/api/js?sensor=false&callback=gMapsCallback");
        (document.getElementsByTagName("head")[0] || document.documentElement).appendChild(script_tag);
    }
    $(window).bind('gMapsLoaded', initialize);
    loadGoogleMaps();
})());​

EDIT
The loadGoogleMaps function might be more practical if declared in the global scope, especially when working in an ajax application. And a boolean check will prevent loading the api multiple times because of navigation.

var gMapsLoaded = false;
window.gMapsCallback = function(){
    gMapsLoaded = true;
    $(window).trigger('gMapsLoaded');
}
window.loadGoogleMaps = function(){
    if(gMapsLoaded) return window.gMapsCallback();
    var script_tag = document.createElement('script');
    script_tag.setAttribute("type","text/javascript");
    script_tag.setAttribute("src","http://maps.google.com/maps/api/js?sensor=false&callback=gMapsCallback");
    (document.getElementsByTagName("head")[0] || document.documentElement).appendChild(script_tag);
}

$(document).ready(function(){
    function initialize(){
        var mapOptions = {
            zoom: 8,
            center: new google.maps.LatLng(47.3239, 5.0428),
            mapTypeId: google.maps.MapTypeId.ROADMAP
        };
        map = new google.maps.Map(document.getElementById('map_canvas'),mapOptions);
    }
    $(window).bind('gMapsLoaded', initialize);
    window.loadGoogleMaps();
});

I’ve done it like so… this example uses jQuery and google map v3.x

$.getScript("http://maps.google.com/maps/api/js?sensor=true&region=nz&async=2&callback=MapApiLoaded", function () {});

function MapApiLoaded() {
   //.... put your map setup code here: new google.maps.Map(...) etc
}

You must use this parameter ‘callback=initialize’ in the google maps API script to load with ajax:

<script src="https://maps.googleapis.com/maps/api/js?v=3.exp&sensor=false&callback=initialize"></script>

Here is a google maps documentation:

Cómo cargar el API de forma asíncrona

Simple and working solution (using jQuery):

var gMapsLoaded = false;

function loadGoogleMaps() { if(!gMapsLoaded) { $.getScript("https://maps.googleapis.com/maps/api/js?sensor=false&async=2&callback=GoogleMapsLoaded", function(){}); } else { GoogleMapsLoaded(); } }

function GoogleMapsLoaded() {

   gMapsLoaded = true;

   // your code here - init map ...
}

paste this in your scripts and then call function loadGoogleMaps(); when you need it!

I’ve changed a little bit Myster sample, that looks working well for me

    window.mapapiloaded = function () {
        console.log('$.ajax done: use google.maps');
        createusinggmaps();
    };

    $.ajax({
        url: 'http://maps.google.com/-maps/api/js?v=3.2&sensor=true&region=it&async=2&callback=mapapiloaded',
        dataType: 'script',
        timeout: 30000, 
        success: function () {
            console.log('$.ajax progress: waiting for mapapiloaded callback');
        },
        error: function () {
            console.log('$.ajax fail: use osm instead of google.maps');
            createusingosm();
        }
    });

$LAB
  .setOptions({AlwaysPreserveOrder:true})
  .script("http://maps.google.com/maps/api/js?v=3.exp&sensor=false&async=2")
  .script("http://maps.gstatic.com/intl/en_us/mapfiles/api-3/13/6/main.js")
  .script("script.js");

Inside of script.js initialize your map without googles load method for example:

Namespace.map = (function(){

    var map,
        markers = [];

    return{
        init: function(){
                var myLatlng = new google.maps.LatLng(-25.363882,131.044922),

                    mapOptions = {
                      zoom: 4,
                      center: myLatlng,
                      mapTypeId: google.maps.MapTypeId.ROADMAP
                    };

                map = new google.maps.Map(document.getElementById('map-canvas'), mapOptions);

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

                markers.push(marker);
            }
    };

}());

Inside of script.js:

Namespace.map.init();

// Don't use: google.maps.event.addDomListener(window, 'load', initialize);

Note: Do not rely on this method as Google changes the name of the second js file. Here is an example from their documentation:

https://developers.google.com/maps/documentation/javascript/examples/map-simple-async

It is now possible. See here
On that page there is also a variant for manual loading, without library.

npm install @googlemaps/js-api-loader


import { Loader } from "@googlemaps/js-api-loader"


const loader = new Loader({
apiKey: "YOUR_API_KEY",
version: "weekly",
...additionalOptions,
});

loader.load().then(() => {
 map = new google.maps.Map(document.getElementById("map") as HTMLElement, {
 center: { lat: -34.397, lng: 150.644 },
 zoom: 8,
  });
});