[ionic v4 beta.3] Can’t apply virtualTrackBy on virtual-scroll component

Bug Report

Ionic Info


   ionic (Ionic CLI)          : 4.1.0
   Ionic Framework            : @ionic/angular 4.0.0-beta.3
   @angular-devkit/core       : 0.7.2
   @angular-devkit/schematics : 0.7.2
   @angular/cli               : 6.1.2   @ionic/ng-toolkit          : 1.0.5
   @ionic/schematics-angular  : 1.0.4


   cordova (Cordova CLI) : 6.5.0   Cordova Platforms     : none   Cordova Plugins       : no whitelisted plugins (0 plugins total)


   ios-deploy : 1.9.2
   ios-sim    : 6.1.3
   NodeJS     : v8.9.4 (/usr/local/bin/node)
   npm        : 5.6.0
   OS         : macOS High Sierra
   Xcode      : Xcode 9.4.1 Build version 9F2000


   ANDROID_HOME : not set

Describe the Bug
I cant apply the virtualTrackBy function on this virtual scroll, it tells me Can't bind to 'virtualTrackBy' since it isn't a known property of 'ion-virtual-scroll'. on console. The IonicModule is imported in my module by default.

There is no any docs about virtualTrackBy in v4.

Steps to Reproduce
Steps to reproduce the behavior:

  1. Create any virtual scroll component.
  2. Just give a virtualTrackBy on this component.
  3. It will return this error msg.

Related Code

<ion-virtual-scroll *ngIf="formattedRows.length" [items]="formattedRows" approxItemHeight="40px" [virtualTrackBy]="">
    <div class="data-row" *virtualItem="let item;">
      <div class="data-cell" *ngFor="let data of item | keyvalue" [innerHTML]="data.value"></div>

Author: Fantashit

3 thoughts on “[ionic v4 beta.3] Can’t apply virtualTrackBy on virtual-scroll component

  1. Hi guys, now using the stable release of @ionic/angular, trackBy it’s finally working.

    <ion-virtual-scroll [items]="myList" [trackBy]="trackByFn">
      trackByFn(index, item) {
        return item ? item.id : index;

    I hope now this issue can be closed.

Comments are closed.