hello.component.ts

import { Component, Input } from '@angular/core';

@Component({
  // ...
})
export class HelloComponent  {
  private _primary: boolean;
  @Input() get primary (): boolean {
    return this._primary;
  }
  set primary (newValue: boolean) {
    this._primary = newValue != null && `${newValue}` !== 'false';
  }
}