Question

Why is cdkVirtualFor not rendering new items in Angular?

I'm using cdkVirtualFor in my Angular project, but it's not rendering new items when the data changes. Can someone help me troubleshoot this?

Answer 1

The issue of cdkVirtualFor not rendering new items in Angular often arises from how change detection is managed or configured in your application. Here are the common causes and solutions:

• Data Source Compatibility: Ensure that the data source used with cdkVirtualFor is updated correctly. If you're directly modifying the array, Angular might not detect changes due to its immutability expectations. Use array methods that return a new reference (e.g., concat, slice, or spreading into a new array).

• Proper Binding: Verify that cdkVirtualFor is bound to a valid iterable or observable, such as [cdkVirtualFor]="items", and that items is updated appropriately.

• Scanned and Piped Observables: If the source is an observable, ensure it emits new values with updates. Using RxJS operators like scan or map can help manage and propagate changes effectively.