How to display placeholders in AngularJS for undefined expression values?

Question

If I have an expression {{ x }} and x is undefined or null, then how can I display a placeholder for it?

I provided one solution

Answer 1

I would do it like this, but maybe there is a better way:

angular.module('app').filter('placeholdEmpty', function(){
  return function(input){
    if(!(input == undefined || input == null)){
      return input;
    } else {
      return "placeholder";
    }
  }
});

and then use {{ x | placeholdEmpty}}