javascript - How to check empty object in angular 2 template using *ngIf

Question

I want to check if my object is empty dont render my element, and this is my code:

<div class="comeBack_up" *ngIf="previous_info != {}">
   <a 
      [routerLink]="['Inside_group_page',{'name':previous_info.path | dotTodash }]"
      >
        {{previous_info.title}}
   </a>
</div>

but my code is wrong, what is the best way to do this?

Answer 1

This should do what you want:

<div class="comeBack_up" *ngIf="(previous_info | json) != ({} | json)">

or shorter

<div class="comeBack_up" *ngIf="(previous_info | json) != '{}'">

Each {} creates a new instance and ==== comparison of different objects instances always results in false. When they are convert to strings === results to true

Plunker example