Migration guide needed for Zone.js apps upgrading to ngx-bootstrap 21.2+

[awaismalik47]

ngx-bootstrap 21.2.0 dropped Zone.js as a dependency in favour of zoneless Angular. This is the right long-term direction, but it creates a gap for the large number of production Angular applications still running with Zone.js that want to upgrade ngx-bootstrap.

Problem
With ngx-bootstrap no longer running its internal async operations inside Zone.js, Angular's change detection is no longer automatically notified when ngx-bootstrap components update their internal state (e.g. modal shown/hidden, datepicker selection, dropdown toggle).

For apps using ChangeDetectionStrategy.OnPush this means UI can appear stale after ngx-bootstrap interactions — no error is thrown, the component simply doesn't re-render.

Questions
Will applications still using Zone.js be unable to use ngx-bootstrap 21.2+ until they have fully migrated to zoneless?
Is there an officially supported path for Zone.js apps to use newer versions of ngx-bootstrap during a gradual migration?
Is there any alternate till i can update my project to zonless?

let me know any alternate apparoch so i can update the project with latest ngx bootstrap

My project current version:
Angular: ~21.2.15
ngx-bootstrap: ^21.0.1

[sherlock1982]

The answer is yes you still can use zone.
Zone is still supported but in Angular 21 you need to opt-in. Just provide somewhere:

bootstrapApplication(AppComponent, {
    providers: [
        provideZoneChangeDetection(),

And don't forget to

import 'zone.js';

somewhere in polyfills

Though zoneless migration is another task but it might be quite big.

[lexasq]

Zoneless approach is backwards compatible, so you shouldn't experience issues.

[xfh]

Unfortunately, the migration to zoneless introduced major performance penalties. Several Browser-Events like Scrolling that were previously wrapped by ngZone.runOutsideAngular(() => {...}) are now triggering a lot of change detection cycles in apps that still require zone.js

Here an example:
v21.0.1...v21.2.0#diff-56c309ebee98ea0e2e29d4ffdf871d2b09d575754389e33340719ffd62d4d1acR58-R84

ngZone.runOutsideAngular is still available in zoneless-apps and should be re-introduced in ngx-bootstrap.

[lexasq]

Thanks for the report @xfh , if you could provide a sampel I'll see what I can work out with our solution.

[xfh]

here is a demo: https://stackblitz.com/~/github.com/xfh/ngx-bootstrap-ngZone

[Maxie42]

So this whole thing happened in #6804 and it also removed the forRoots which is most definitely a breaking change, not to mention the title 22.2 contradicts the final version 21.2. This definitely should have been a breaking change guys, what about semver?

[lexasq]

@Maxie42 ForRoots were deprecated a long time ago an supposed to be removed in v19, but as I didn't have time they lived.
Title is irrelevant in this case.
This is indeed a breaking change and it was mentioned on changelog.

@xfh thanks for the demo, I'll check how to work this out

[Maxie42]

Breaking means major in the world of semver :)

[lexasq]

We're syncing major with angular :)

[Maxie42]

Then remove it when you update angular :)

[lexasq]

Well, as it is an opensource project you can always make it yourself :)

[Maxie42]

I tried making prs myself but they have been pending review since last September..

[lexasq]

Because new features are postponed in favor of more pressing matters like zoneless and bugfixing. Datepicker is a pain as it is, I was working out issues when I could. But o well.

[Maxie42]

Look I'm just trying to explain that a breaking change is a breaking change regardless of angular versions. We depend on a library that uses ngx bootstrap with ^21.0.0 and still uses for root. Now since they are so lenient me the descendant were able to add 21.2 in my app, and where I used for root I could clean it up, but obviously I can't fix it in their end. All I can do is pin it down to a lower version or override it for now until they have time to fix it. Had this been a breaking change this would never happened. Now even if I update or if they will I'm going to make sure the exact version cause I can't trust that we won't get another breaking change on a minor or even patch..

BTW postponed for a year I mean come on? :)