StyleGuide - Prefer inputs over the @Attribute parameter decorator

[johnpapa]

*To be discussed ... *

I copied several of these from early discussions and will list them as issues for future discussion after ngConf

cc // @mgechev @wardbell

• Prefer inputs over the @Attribute parameter decorator.

  Why?: The input creates one-way binding which means that we can bind it to an expression and its value gets automatically updated. We can inject a property with @Attribute to a controller's constructor and get its value a single time.

  /* AVOID */
  @Component({
    selector: 'sg-button',
    template: `...`
  })
  class ButtonComponent {
    label: string;
    constructor(@Attribute('label') label) {
      this.label = label;
    }
  }

  /* RECOMMENDED */
  @Component({
    selector: 'sg-button',
    template: `...`
  })
  class ButtonComponent {
    @Input() label: string;
  }

[zoechi]

We can inject a property with @Attribute to a controller's constructor and get its value a single time.

I think this should be inject an attribute instead of inject a property. This can only be used to read statically added attributes AFAIK.