[Accordion] onOpen and onClose emitter won't trigger any events with the new components for accordion

[ruthjohnstonmusic]

Describe the bug

The onOpen and onClose emitter for accordion don't work with the new accordion-header and accordion-content components. The events are triggered when you use the old component p-accordionTab or p-accordion-tab. I see this issue has been resolved for v19 but it is also occurring in v18 and I'm not sure if the fix for 19 will be applied to 18 as well.

Pull Request Link

No response

Reason for not contributing a PR

• Lack of time
• Unsure how to implement the fix/feature
• Difficulty understanding the codebase
• Other

Other Reason

No response

Reproducer

https://stackblitz.com/edit/github-8n33ys8f?file=src%2Fapp%2Ftest%2Ftest.component.html

Environment

stackblitz

Angular version

18.1.2

PrimeNG version

v18 (LTS Only)

Node version

22.5.1

Browser(s)

No response

Steps to reproduce the behavior

Link the onClose or onOpen Emitter to p-accordion with p-accordion-panel, header, content.
Try to open or close and accordion panel and nothing is triggered.

Expected behavior

Trigger the events for the onClose and onOpen Emitters with the new accordion components.

[gregorwinkler]

With PrimeNG 19.0.8 the events are triggered but the emitted index is always -1 which is not how it was in older PrimeNG versions.