Wait for globals to be present

wait-for-global.js

// Micro utility to execute a function when all globals are present

var waitForGlobal = function(params) {
    var pathExists = function( arr, obj ) {
        var target = obj[ arr.shift() ];
        var exists = target !== undefined;
        return arr.length == 0 ? exists : exists && pathExists(arr, target);
    };
    var predicate = function() {
        return params.globals.every(function(path) {
            return pathExists(path.split('.'), window);
        });
    };
    var wait = function() {
        setTimeout( function() { 
            predicate() && (params.callback() || true) || wait();
        }, 30);
    };
    wait();
};

waitForGlobal({
    globals: [ 'google.maps', 'initApp', 'fakeDep' ],
    callback: function() {
        initApp();
    }
});