Using expressions in ngModel in Angular.js

Slava, I’m not too sure if this is a good idea to begin with. But anyhow,
You need to make your model getterSetter aware by adding this property to your input ng-model-options="{ getterSetter: true }.
Then you need a function in your controller that builds a getterSetter out of a sting.

<input type="text" ng-model="propertify('entity.' + path)" ng-model-options="{ getterSetter: true }">

That’s how the resulting template would look.

Luckily angular has an $parse service that makes this a lot easier. so something like this would need to be in your controller, or even better in a injected service.

  $scope.propertify = function (string) {
      var p = $parse(string);
      var s = p.assign;
      return function(newVal) {
          if (newVal) {
              s($scope,newVal);
          }
          return p($scope);
      } ;
  };

That will return a getter-setter function that handles this for you.
see it in action in this plunk