Call a method when ng-template is visible

Question

Does ng-template have any events when it is visible or active in the scope or is it possible to execute any method in such way to call it from the container?

<ng-template (active/vissible)="callMethod()"> ... </ng-template>

(Or)

<ng-container *ngTemplateOutlet="mytemplate" ></ng-container>

Does the template only become visible at some point, or does it also go from visible to not visible? — ConnorsFan, Apr 19 '18 at 17:49
it only gets visible at some point It is being used within an ng-tabset — Mahi Tej Gvp, Apr 19 '18 at 17:52

score 3 · Answer 1 · answered Apr 19 '18 at 17:52

3

One option could be (valid for any DOM object) is via ViewChildren's QueryList's changes. You mark any DOM element (or use it's type) - <div #myEl></div>

Assign it:

@ViewChildren('myEl') myEl: QueryList<any>;

And subscribe for changes in ngAfterViewInit (as earlier AFAIK its not yet created):

ngAfterViewInit() {
  this.myEl.changes.subscribe(_ => console.log(_));
}

answered Apr 19 '18 at 17:52

Julius Dzidzevičius

10,775
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1

I am not familiar with ngTabset, but this should work with any DOM element – Julius Dzidzevičius Apr 19 '18 at 18:05
isn't there any other way to implement it other than a lifecycle hook – Mahi Tej Gvp Apr 19 '18 at 19:32
Pretty sure there are other ways. Why you dont want lifecycle hook? – Julius Dzidzevičius Apr 20 '18 at 04:19

score -1 · Answer 2 · answered Apr 19 '18 at 17:15

-1

You can use

public mycondition: boolean = true;   ///according to need make it true or false

<ng-template *ngIf="mycondition"> ... </ng-template>

answered Apr 19 '18 at 17:15

Lavkush Gupta

103
13

can I call a method from it ? @Lavkush Gupta I need to call a method when the template is vissible – Mahi Tej Gvp Apr 19 '18 at 17:24
Yes Of cause you can call a method – Lavkush Gupta Apr 19 '18 at 17:27
I do not want to make the view visible/hide with *ngIf I need it to notify to the component that it is active or vissible like an event – Mahi Tej Gvp Apr 19 '18 at 17:31

Call a method when ng-template is visible

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