Angular2 Init and destroy component

Question

Developers. There's a problem with <ng-content></ng-content> . I have created a component and it look's like this. But component <boat></boat> <competitorEvent ></competitorEvent > and <waypoint ></waypoint> initializes one time and don not get destroyed

 <tabs> <tab number="{{event?.boats?.length}}" title="{{'CATEGORY.BOATS' | translate}}" icon="directions_boat"> <boat [data]=event?.boats></boat> </tab> <tab number="{{event?.competitors?.length}}" title="{{'CATEGORY.COMPETITOR' | translate}}" icon="people"> <competitorEvent [data]="event?.competitors"></competitorEvent> </tab> <tab number="{{event?.wayPoints?.length}}" title="{{'CATEGORY.WAYPOINTS' | translate}}" icon="place"> <waypoint [distances]="event?.distances"></waypoint> </tab> </tabs> 

 tabs.ts @Component({ selector: "tabs", template: ` <div class="ui-g"> <ng-container *ngFor="let tab of tabs" > <div class="ui-g-12 ui-md-2 ui-lg-2" (click)="selectTab(tab)"> <a> <div class="ui-g card colorbox colorbox-1" [class.active]="tab.pressed"> <div class="ui-g-4" *ngIf="tab.icon"> <i class="material-icons">{{tab.icon}}</i> </div> <div class="ui-g-8"> <div class="colorbox-name truncate">{{tab.title}}</div> <div class="colorbox-count">{{tab.number}}</div> </div> </div> </a> </div> </ng-container> </div> <ng-content ></ng-content> ` }) 

 tab.ts @Component({ selector: "tab", template: ` <ng-template class="container" *ngIf="pressed"> <ng-content *ngIf="pressed"></ng-content> </ng-template> ` }) 

In this code when you click each component launches component lifecycle everytime

 <div [ngSwitch]="tab"> <div *ngSwitchCase="1"> <boat [data]=event?.boats></boat> </div> <div *ngSwitchCase="2"> <competitorEvent [data]="event?.competitors"></competitorEvent> </div> <div *ngSwitchCase="3"> <waypoint [distances]="event?.distances"></waypoint> </div> </div> 

Answer 1

update Angular 5

ngOutletContext was renamed to ngTemplateOutletContext

See also https://github.com/angular/angular/blob/master/CHANGELOG.md#500-beta5-2017-08-29

original

<ng-content *ngIf="pressed"></ng-content>

doesn't create or destroy the content projected through them, it's just a marker where child content should be displayed (projected to).

The content stays part of the component where it's actually added.

To have more control you could pass <template><boat></boat></template> and add it using ngTemplateOutlet (or similar) in TabComponent.

Another alternative would be

<tab number="{{event?.boats?.length}}" title="{{'CATEGORY.BOATS' | translate}}" icon="directions_boat" #tab>
    <boat *ngIf="tab.visible" [data]=event?.boats></boat>

where TabComponent provides a property visible that the child uses to get itself added/removed depending on the value of visible .