@Component({
selector: "parent",
template: `<child [userId]="(userId$ | async)"></child>`,
changeDetection: ChangeDetectionStrategy.OnPush
})
export class ParentCmp implements OnInit {
userId$: BehaviorSubject<string> = new BehaviorSubject<string>(null);
constructor(private activatedRoute: ActivatedRoute) { }
ngOnInit() {
this.activatedRoute.queryParams.subscribe(query => {
//notify child with BehaviorSubject
this.userId$.next(query["userid"])
}
}
}
@Component({
selector: "child",
template: `<div *ngIf="(userState$ | async) && userId">
{{(userState$ | async).user.id)}}
</div>`,
changeDetection: ChangeDetectionStrategy.OnPush
})
export class ChildCmp implements OnChanges {
@Input() userId: string;
private userState$: Observable<User>;
constructor(private store: Store<store.AppState>) { }
ngOnChanges(changes: SimpleChanges) {
//when it gets userId it starts to track fit user in ngrx store
this.userState$ = this.store
.select(state => state.user-list)
.map(userList => userList[this.userId])
.filter(user => !!user);
}
}
Child cmp從父級獲取userId並且需要用戶包含在ngrx store(userList)中,但是不會重新呈現子視圖。當兒童的ChangeDetectionStrategy是默認值時,它完美地工作。這裏有什麼可能是錯的? 角V2.4使用OnPush策略時,子組件的視圖不會被重新渲染
你可以創建plunker嗎? – yurzui