为什么自定义组件在ionic 2中创建页面之前运行？

Question

I would like to implement a custom component in my ionic project and I followed this guide to realize it.

On my page, instantiate a variable to pass to my component

export class NewSegmentPage {

name: any;

constructor(public navCtrl: NavController, public navParams: NavParams) {
this.name = "hello";      
}

and in the template

...
<ion-content>
  <slider [name]="name"></slider>
</ion-content>

Now I create my component

<ion-item>
  <ion-range dualKnobs="true" pin="true" [(ngModel)]="structure"></ion-range>
</ion-item>

and retrieve the data that I pass to the variable by @Input

@Input("coordinates") activity;
structure: any = { lower: 33, upper: 60 };

constructor() {
   console.log(this.activity);
}

but this.activity variable is undefined.

In addition, in the google console I saw that the component is created before the page and that's why it fails to pass the data. But, How does it behave like that?

Answer 1

The execution is right but I was wrong to retrieve the this.activity variable in the constructor. Off of my constructor my variable is instantiated.

ngAfterViewInit() {
   console.log(this.activity);    
}