Tips for retrieving input data sent from the parent component in Angular 2

Question

Tips for retrieving input data sent from the parent component in Angular 2

I am working on a playlist component that receives an input 'playlist' from its parent component. This input is an object of arrays structured as follows:

  playList: {
    headerPlaylists: Array<any>,
    bodyPlaylists: Array<any>
  } = {
    headerPlaylists: [],
    bodyPlaylists: []
  }

The child component code looks like this:

@Component({
  selector: 'playlist',
  styleUrls: ['app/channel/playlist/playlist.css'],
  templateUrl: 'app/channel/playlist/playlist.html',
  directives: [VideoItemComponent],
  inputs: ['playlist']
})

My main question is, how can I access the 'playlist' input in my class? For example, if I want to simply log the playlist contents using console.log(playlist), what would be the correct way to do so?

export class PlaylistComponent {

  constructor() {

  }
}

angular typescript

Answer 1

Answer №1

Thierry's insight regarding the availability of inputs throughout the lifecycle is accurate, however, a more intuitive approach can be achieved by utilizing @Input() on the field instead of specifying them as inputs in the metadata.

@Component({
  selector: 'playlist',
  styleUrls: ['app/channel/playlist/playlist.css'],
  templateUrl: 'app/channel/playlist/playlist.html',
  directives: [VideoItemComponent],
 // inputs: ['playlist'] // would be redundant
})
class PlaylistComponent implements OnInit {
  @Input() playlist: YourPlaylistType; // Represents the data structure provided

  ngOnInit(){
     // Access and utilize this.playlist 
  }
}

It's worth noting that, primarily for clarity purposes, defining inputs using @Input() is favored over the conventional method according to the ng2 style guide.

Answer 2

Thierry's insight regarding the availability of inputs throughout the lifecycle is accurate, however, a more intuitive approach can be achieved by utilizing @Input() on the field instead of specifying them as inputs in the metadata.

@Component({
  selector: 'playlist',
  styleUrls: ['app/channel/playlist/playlist.css'],
  templateUrl: 'app/channel/playlist/playlist.html',
  directives: [VideoItemComponent],
 // inputs: ['playlist'] // would be redundant
})
class PlaylistComponent implements OnInit {
  @Input() playlist: YourPlaylistType; // Represents the data structure provided

  ngOnInit(){
     // Access and utilize this.playlist 
  }
}

It's worth noting that, primarily for clarity purposes, defining inputs using @Input() is favored over the conventional method according to the ng2 style guide.

Answer 3

Answer №2

The playlist property will be accessible in the ngOnInit hook method of this component:

export class PlaylistComponent {
  playlist: any; // or a specific type instead of any

  constructor() {
    console.log(this.playlist); // returns null
  }

  ngOnInit() {
    console.log(this.playlist); // is now set
  }
}

In the constructor, the property remains unset.

For additional information, check out this page regarding lifecycle hooks:

https://angular.io/docs/ts/latest/guide/lifecycle-hooks.html

Answer 4

The playlist property will be accessible in the ngOnInit hook method of this component:

export class PlaylistComponent {
  playlist: any; // or a specific type instead of any

  constructor() {
    console.log(this.playlist); // returns null
  }

  ngOnInit() {
    console.log(this.playlist); // is now set
  }
}

In the constructor, the property remains unset.

For additional information, check out this page regarding lifecycle hooks:

https://angular.io/docs/ts/latest/guide/lifecycle-hooks.html

Tips for retrieving input data sent from the parent component in Angular 2

Answer №1

Answer №2

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