p-dropdown: p-dropdown-open style is missing from dropdown

[jaspertolsma]

Describe the bug

We have a chevron icon that rotates when our p-dropdowns are opened. To detect whether a dropdown is opened we use the p-dropdown-open class. We were on PrimeNG 15.4.1 and updated recently to PrimeNG 17.7.0. In this version of PrimeNG the p-dropdown is missing the p-dropdown-open class. It is still mentioned in the docs, however in this commit you can see it is removed. Without this class we cannot detect whether the dropdown is opened.

The p-inputwrapper-focus class has partial overlap with the p-dropdown-open class, but is also set when the dropdown is focused, but not opened, so doesn't fit our use case.

Environment

Chrome

Reproducer

No response

Angular version

17.3.10

PrimeNG version

17.17.0

Build / Runtime

Angular CLI App

Language

TypeScript

Node version (for AoT issues node --version)

18

Browser(s)

No response

Steps to reproduce the behavior

1. Open a primeng dropdown
2. See in the html that the class p-dropdown-open is not set.

Expected behavior

1. Open a primeng dropdown
2. The class p-dropdown-open is set on the dropdown.

[B34v0n]

Hi, I just had the same issue, but I was able to find a workaround.
You can use the aria-expanded-tag to see if it is opened:

p-dropdown div.p-dropdown div.p-dropdown-trigger[aria-expanded='true'] {
    rotate: 180deg;
}

[willmca]

@jaspertolsma @B34v0n I have raised a PR that will address this issue