Dropdown an passing options with an async pipe

[rehdie]

Unfortunately the AsyncPipe of angular potentially returns null, which cause a compile error when using the async-pipe for the options of a dropdown like this:

<p-dropdown ..... [options]="options$ | async" />

It would be great to allow the options to be null (for now only undefined and [] is allowed):

set options(val: any[] | undefined)

The only workaround for now is this ugly code:

[options]="(countries$ | async) || []"