promise.js

this.getCurrentPosition = function() {
    var position = $q.defer();

    geolocation.getCurrentPosition(function(pos) {
        position.resolve(pos);
    }, function() {
        position.reject();
    });

    return position.promise;
};

this.render = function() {
  this.getCurrentPosition.then(function(position) {
    // modifica aqui o dom
  });
}