Simple on-demand lazy loader for the Google Maps Geocoding service

geocoder.js

/**
 * Geocoder is a simple on-demand lazy loader for the Google Maps Geocoding service
 *
 * Usage: `Geocoder.call(function (geocoder) {});`
 */
var Geocoder = (function (self) {
    var _geocoder = null;

    self.call = function (cb) {
        // available
        if (_geocoder) {
            cb(_geocoder);
            return;
        }

        // maps api available
        if (window.google && window.google.maps) {
            _geocoder = new google.maps.Geocoder;
            cb(_geocoder);
            return;
        }

        // maps api unavailable -- load it
        var callbackId = 'geocoder_' + Math.random().toString(36).slice(2);

        window[callbackId] = function () {
            _geocoder = new google.maps.Geocoder;
            cb(_geocoder);
        };

        var script = document.createElement('script');
        script.type = 'text/javascript';
        script.src = '//maps.google.ch/maps/api/js?v=3.9&sensor=false&callback=' + callbackId;
        document.body.appendChild(script);
    };

    return self;

})(Geocoder || {});