Angular - ng-template with parameter inside ngIf inside ngFor

Question

I am trying to build this template:

<ul>
    <li *ngFor='let link of links'>
        <ng-container *ngIf="link.type == 'complex'; then complexLink else simpleLink"></ng-container>
    </li>
</ul>

<ng-template #simpleLink>
    ...
    {{ link.some_property }}
</ng-template>

<ng-template #complexLink>
    ...
    {{ link.some_property }}
</ng-template>

The problem is that the link variable is undefined inside the ng-template so I get an error of accessing 'some_property' of undefined.

I am struggeling to understand how I pass the link variable from the ngFor to the ng-template

It would be great to know if there are multiple solutions for this problem.

Vivek Doshi · Accepted Answer · 2018-11-06T13:49:20.827

271

You can do it like :

<ul>
    <li *ngFor='let link of links'>
        <ng-container 
             [ngTemplateOutlet]="link.type == 'complex' ?complexLink : simpleLink" 
             [ngTemplateOutletContext]="{link:link}">
        </ng-container>
    </li>
</ul>

<ng-template #simpleLink let-link='link'>
    Simple : {{ link.name }}
</ng-template>

<ng-template #complexLink let-link='link'>
    Complex : {{ link.name }}
</ng-template>

WORKING DEMO

edited Nov 06 '18 at 13:49

answered Jan 30 '18 at 06:40

Vivek Doshi

52,153
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1

Hi Vivek i need to pass external values like output to access [ngTemplateOutletContext] in another component refer this plunker:https://plnkr.co/edit/lHFWI9KEHXPaJT4YKDkD?p=preview – Venkateswaran R Jan 30 '18 at 07:39
3

Your answer helped me grasp the concept that each `ng-template` has its own context of template variables. Ended up helping me build a great page. Thanks! – Jacob Stamm Jun 12 '18 at 15:35
17

Updated syntax: `` https://angular.io/api/common/NgTemplateOutlet – Anis Abboud Jun 06 '19 at 10:58
Hey Vivek, is it possible to pass multiple values at once? Thanks for the example though. – Hemang Jun 24 '20 at 19:40
1

Yes you can pass json to `ngTemplateOutletContext`,as shown above each key considered as variable – Vivek Doshi Jun 25 '20 at 02:47
That's pretty awesome! :) – Mateusz Moroz Nov 05 '20 at 12:22

score -18 · Answer 2 · answered Jan 30 '18 at 06:49

You can use it in this way

<ul>
  <li *ngFor='let link of links'>
      <ng-container *ngIf="link.type == 'complex'; then complexLink else simpleLink"></ng-container>

      <ng-template #simpleLink>
          ... {{ link.some_property }}
      </ng-template>

      <ng-template #complexLink>
          ... {{ link.some_property }}
      </ng-template>
  </li>
</ul>

Angular - ng-template with parameter inside ngIf inside ngFor

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