Angular - how to check length of Array in *ngFor, when using Async pipe?

Question

I have:

<mat-toolbar-row *ngFor="let idp of Idps | async; last as isLast">

and I need to access the length of it for these:

 <button [disabled]="(Idps| async)?.length===1" [ngClass]="{'disabledBtn': !(Idps | async)?.length > 1}"

this sadly does not work, I managed to make that syntax work only here:

{{ (Idps | async)?.length }}

if I put this in my HTML, it will show on screen the length, but I cannot find the right syntax to use for my [disabled] and [ngClass] tags

Chris · Accepted Answer · 2020-04-17 13:34:34Z

5

Use local variable from NgForOf directive ("count")

<mat-toolbar-row *ngFor="let idp of Idps | async; last as isLast; count as count">

Here you can find all the variables available for NgForOf directive

answered Apr 17, 2020 at 13:27

Chris

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1 Comment

It worth to add that full list of available variables can be found at angular.io/api/common/NgForOf#local-variables