Property showDropdownIfEmpty of TagInputDropdown not working as expected

[piraces]

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[ ] support request/question

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Current behavior

• The input showDropdownIfEmpty of TagInputDropdown is not working as expected. It currently does not show the dropdown when focusing the form input (while is true). Not working with clicks in different areas, selections, keys... This behaviour can be also seen in the live demo (example with the title 'Tags accepting only items from an autocomplete using an observable and showing dropdown without entering text').

Expected behavior

• The input showDropdownIfEmpty if set to true (as docs explains) should show the autocomplete dropdown as soon as the user focuses on the form.

Minimal reproduction of the problem with instructions (if applicable)

If using TagInputDropdown with autocomplete and you set the showDropdownIfEmpty to true, the dropdown is not shown when the user focus the form.

An example code can be seen in this repo: https://github.com/Gbuomprisco/ngx-chips/blob/03875e13177b6d845c0bc6b319bbeabaf7344240/demo/home/home.html#L110

Reproducible at the live demo.

What do you use to build your app?. Please specify the version

Angular-cli v8.3.20.

Angular version:

Angular 8.2.14.

ngx-chips version:

ngx-chips 2.1.0 (latest)

Browser:

Chrome, Edge (Chromium).

Related issue (but not same): #768