Correct use of Elvis operator in Angular2 for Dart component's view

Question

I see in Angular2 Dart Angular for Dart Cheat Sheet (v2.0.0-beta.2) that the Elvis operator is supported.

I am trying to use it in an a components view but it seems

Answer 1

Go to your component.ts class and initialize the model's properties to "" or whatever the appropriate default value should be.

A good place would be ngOnInit() method.

This helped me on Angular 5.