ng-content

ng-bind

app.directive('ngBindAttrs', function() {
  return function(scope, element, attrs) {
    scope.$watch(attrs.ngBindAttrs, function(value) {
      angular.forEach(value, function(value, key) {
        attrs.$set(key, value);
      })
    }, true)
  }
});



<input type="text" ng-bind-attrs="{placeholder: somePropertyOfTheScope, tabindex: anotherPropertyOfTheScope}" >