AngularJS directives for Baidu Maps

/** *  A directive which helps you easily show a baidu-map on your page. * * *  Usages: * *      <baidu-map options="options"></baidu-map> * *      options: The configurations for the map *            .width[Number]{M}:        The width of the map *            .height[Number]{M}:       The height of the map *            .center.longitude[Number]{M}: The longitude of the center point *            .center.latitude[Number]{M}: The latitude of the center point *            .zoom[Number]{O}:         Map's zoom level. This must be a number between 3 and 19 *            .navCtrl[Boolean]{O}:     Whether to add a NavigationControl to the map *            .scaleCtrl[Boolean]{O}:   Whether to add a ScaleControl to the map *            .overviewCtrl[Boolean]{O}: Whether to add a OverviewMapControl to the map *            .enableScrollWheelZoom[Boolean]{O}: Whether to enableScrollWheelZoom to the map *            .city[String]{M}:         The city name which you want to display on the map *            .markers[Array]{O}:       An array of marker which will be added on the map *                   .longitude{M}:                The longitude of the marker *                   .latitude{M}:                 The latitude of the marker *                   .icon[String]{O}:             The icon's url for the marker *                   .width[Number]{O}:            The icon's width for the icon *                   .height[Number]{O}:           The icon's height for the icon *                   .title[String]{O}:            The title on the infowindow displayed once you click the marker *                   .content[String]{O}:          The content on the infowindow displayed once you click the marker *                   .enableMessage[Boolean]{O}:   Whether to enable the SMS feature for this marker window. This option only available when title/content are defined. * * * *  @author      Howard.Zuo *  @copyright   April 9, 2014 *  @version     1.0.4 * */(function(angular) {    "use strict";    var defaults = {        navCtrl: true,        scaleCtrl: true,        overviewCtrl: true,        enableScrollWheelZoom: true,        zoom: 10    };    var checkNull = function(obj) {        return obj === null || obj === undefined;    };    var checkMandatory = function(prop, desc) {        if (!prop) {            throw new Error(desc);        }    };    /**     * Construction function     *     * @constructor     */    var baiduMapDir = function() {        // Return configured, directive instance        return {            restrict: 'E',            scope: {                'options': '='            },            link: function($scope, element, attrs) {                var ops = {};                ops.navCtrl = checkNull($scope.options.navCtrl) ? defaults.navCtrl : $scope.options.navCtrl;                ops.scaleCtrl = checkNull($scope.options.scaleCtrl) ? defaults.scaleCtrl : $scope.options.scaleCtrl;                ops.overviewCtrl = checkNull($scope.options.overviewCtrl) ? defaults.overviewCtrl : $scope.options.overviewCtrl;                ops.enableScrollWheelZoom = checkNull($scope.options.enableScrollWheelZoom) ? defaults.enableScrollWheelZoom : $scope.options.enableScrollWheelZoom;                ops.zoom = checkNull($scope.options.zoom) ? defaults.zoom : $scope.options.zoom;                checkMandatory($scope.options.width, 'options.width must be set');                checkMandatory($scope.options.height, 'options.height must be set');                checkMandatory($scope.options.center, 'options.center must be set');                checkMandatory($scope.options.center.longitude, 'options.center.longitude must be set');                checkMandatory($scope.options.center.latitude, 'options.center.latitude must be set');                checkMandatory($scope.options.city, 'options.city must be set');                ops.width = $scope.options.width;                ops.height = $scope.options.height;                ops.center = {                    longitude: $scope.options.center.longitude,                    latitude: $scope.options.center.latitude                };                ops.city = $scope.options.city;                ops.markers = $scope.options.markers;                element.find('div').css('width', ops.width + 'px');                element.find('div').css('height', ops.height + 'px');                // create map instance                var map = new BMap.Map(element.find('div')[0]);                // init map, set central location and zoom level                map.centerAndZoom(new BMap.Point(ops.center.longitude, ops.center.latitude), ops.zoom);                if (ops.navCtrl) {                    // add navigation control                    map.addControl(new BMap.NavigationControl());                }                if (ops.scaleCtrl) {                    // add scale control                    map.addControl(new BMap.ScaleControl());                }                if (ops.overviewCtrl) {                    //add overview map control                    map.addControl(new BMap.OverviewMapControl());                }                if (ops.enableScrollWheelZoom) {                    //enable scroll wheel zoom                    map.enableScrollWheelZoom();                }                // set the city name                map.setCurrentCity(ops.city);                if (!ops.markers) {                    return;                }                //create markers                var openInfoWindow = function(infoWin) {                    return function() {                        this.openInfoWindow(infoWin);                    };                };                for (var i in ops.markers) {                    var marker = ops.markers[i];                    var pt = new BMap.Point(marker.longitude, marker.latitude);                    var marker2;                    if (marker.icon) {                        var icon = new BMap.Icon(marker.icon, new BMap.Size(marker.width, marker.height));                        marker2 = new BMap.Marker(pt, {                            icon: icon                        });                    }                    else {                        marker2 = new BMap.Marker(pt);                    }                    // add marker to the map                    map.addOverlay(marker2); // 将标注添加到地图中                    if (!marker.title && !marker.content) {                        return;                    }                    var infoWindow2 = new BMap.InfoWindow("<p>" + (marker.title ? marker.title : '') + "</p><p>" + (marker.content ? marker.content : '') + "</p>", {                        enableMessage: checkNull(marker.enableMessage) ? false : marker.enableMessage                    });                    marker2.addEventListener("click", openInfoWindow(infoWindow2));                }            },            template: '<div></div>'        };    };    var baiduMap = angular.module('baiduMap', []);    baiduMap.directive('baiduMap', [baiduMapDir]);})(angular);