如何在SAP UI5 JS视图中从构造函数对象接收属性值

Question

I coded an object constructor in util.Common.js file which enable me to receive this object from everywhere. Here my object constructor taken from javascript google maps examples

jQuery.sap.declare("util.Common");

util.Common = {
    /** @constructor */
    MercatorProjection : function() {
        this.TILE_SIZE = 256;
        this.pixelOrigin_ = new google.maps.Point(this.TILE_SIZE / 2,
          this.TILE_SIZE / 2);
        this.pixelsPerLonDegree_ = this.TILE_SIZE / 360;
        this.pixelsPerLonRadian_ = this.TILE_SIZE / (2 * Math.PI);
        Map.prototype.googlemap = null;

        this.createMap = function(mapOptions){
            Map.prototype.mapOptions = mapOptions;
            Map.prototype.googlemap = new google.maps.Map(Map.prototype.map_canvas_div.getDomRef(),  
            Map.prototype.mapOptions);
        };

        this.createInfoWindowContent = function(map) {
            var numTiles = 1 << map.getZoom();
            var projection = new MercatorProjection();
            var worldCoordinate = projection.fromLatLngToPoint(chicago);
            var pixelCoordinate = new google.maps.Point(
              worldCoordinate.x * numTiles,
              worldCoordinate.y * numTiles);
            var tileCoordinate = new google.maps.Point(
              Math.floor(pixelCoordinate.x / TILE_SIZE),
              Math.floor(pixelCoordinate.y / TILE_SIZE));

            return [
            'Chicago, IL',
            'LatLng: ' + chicago.lat() + ' , ' + chicago.lng(),
            'World Coordinate: ' + worldCoordinate.x + ' , ' +
              worldCoordinate.y,
            'Pixel Coordinate: ' + Math.floor(pixelCoordinate.x) + ' , ' +
              Math.floor(pixelCoordinate.y),
            'Tile Coordinate: ' + tileCoordinate.x + ' , ' +
              tileCoordinate.y + ' at Zoom Level: ' + map.getZoom()
            ].join('<br>');
        };
        ...
    },
    ...
};

and I'm trying to reach one of properties of object from home.js like that :

var me = new util.Common.MercatorProjection();
var mapOptions = {
   zoom: 3,
   center: chicago
};
me.createMap(mapOptions);

var coordInfoWindow = new google.maps.InfoWindow();
coordInfoWindow.setContent(me.createInfoWindowContent(me.googlemap));
coordInfoWindow.setPosition(me.chicago);
coordInfoWindow.open(me.googlemap);
var listener1 = new google.maps.event.addListener(me.googlemap, 'zoom_changed', function() {
coordInfoWindow.setContent(icm.Google.Charts.values.chart.createInfoWindowContent(me.googlemap));
coordInfoWindow.open(me.googlemap);

But when I write

me.googlemap

it says googlemap is undefined and it couldn't create info window but I created it in createMap function so it shouldn't be undefined I think I just reached this value wrongly so I don't know how I can reach this value. Any suggestion would be very nice thanks in advance.

Answer 1

If you look at your code, you're defining googlemap as a property of Map :

Map.prototype.googlemap = null;

Yet, your object name is MercatorProjection :

MercatorProjection : function() {
...

I assume you want googlemaps to be a property of MercatorProjection (I'm not even sure what Map is?) - if you adjust your code accordingly (changing references to Map to references to MercatorProjection ), your references to me.googlemap further on will work.

Unrelated to your question, but if you're working with Google Maps and UI5, take a look at openui5-googlemaps .