Angular2: *ngFor does not update when array is updated
You could also use the trackBy
option in your *ngFor
expression, providing a unique ID for every item inside the array. This does make you 100% responsible for change detection, so update this (unique) property every time the item in the array changes. Angular will then only re-render the list if any item inside your array has been given a different trackBy
property:
*ngFor="let item of (itemList$ | async); trackBy: trackItem"
or:
*ngFor="let item of itemList; trackBy: trackItem"
where:
trackItem
is a public method in your component:
public trackItem (index: number, item: Item) { return item.trackId;}
Since you mentioned that you already tried markForCheck()
, you should try detectChanges instead (that just what worked for me and markForCheck did not work). For those that need the steps:
Add ChangeDetectorRef to your imports:
import { Component, OnInit, ChangeDetectorRef } from '@angular/core';
Add ChangeDetectorRef to your constructor:
constructor( private changeDetection: ChangeDetectorRef ) { }
Then on the next line after you update the array:
this.changeDetection.detectChanges();
late to the game but creating a deep clone using lodash worked for me
this.arr = cloneDeep(this.arr);