$observe multiple attributes at the same time and fire callback only once

Question

I wonder is it possible to execute some callback only once after evaluation all (or only some) attributes of directive (without isolated scope). Attributes are really great to p

Answer 1

Underscore (or lo-dash) has a once function. If you wrap your function inside once you can ensure your function will be called only once.

angular.module('app', []).

directive('person', function() {
  return {
    restrict: 'A',
    link: function($scope, $elem, $attrs) {
        var action = function() {
          $elem.append('name: ' + $attrs.name + '
 surname: ' + $attrs.surname+'

');
        }
        var once = _.once(action);
        $attrs.$observe('name', once);
        $attrs.$observe('surname', once);
    }
 }
});