gistfile1.js

Ext.define('App.someclass.SomeClass', {

someFunction: function(data) {
		this.offers = someArrayOfOffers();
		var blahCallback = (function (offers, context) {
			return function(points){
				for (var i = 0; i < points.length; i++) {
					Ext.bind(context.onMarkerTap, context, offers[i], points[i])
				}
			}
		})(this.offers, this); // in this case 'this' is a reference to the current class

		// This function expects a callback that accepts an array of points
		BMap.Convertor.translate(data, blahCallback);
	}
})