bootstrap’s invalid feedback is disabled by selectize

[mauricev]

I did:

• [ x] Search for if my issue has already been submitted
• [ x] Make sure I'm reporting something precise that needs to be fixed
• [ x] Give my issue a descriptive and concise title
• Create a minimal working example on JsFiddle or Codepen
  (or gave a link to a demo on the Selectize docs)
• [ x] Indicate precise steps to reproduce in numbers and the result,
  like below

Bootstrap (4) provides an adornment to required items by way of the invalid-feedback class when the item was not filled in or set. It does not work for selectized elements.

Steps to reproduce:

1. Create a selectized dropdown inside a form with some items to choose from
2. Give it the required attribute
3. Put in an enclosing div tag with itself and an invalid-feedback div tag (per bootstrap 4)
4. The form should be setup with class="needs-validation" novalidate
5. Do not select any items in the selectized dropdown
6. Attempt to submit the form

Expected result:
The invalid feedback should display and the form should not be accepted

Actual result:
The invalid feedback never even engages. Repeat the steps above without selectizing the select element and you do you get the invalid-feedback.

[fabienwnklr]

So, the first step of the cause of this error it's in function refreshValidityState the required attribute is removed from the native select or input element (cf : https://github.com/selectize/selectize.js/blob/master/src/selectize.js#L1806) added by this commit from 6 years..

1. So if i remove this line the message is displayed, maybe first step are to remove this ? Is this line still necessary?
2. but there is still a problem : selectize input donc have error style cause Bootstrap use .custom-select OR .form-select and :invalid CSS selector and it's available only any or other elements , the only one solution i found would be to listen to the invalid event and apply the desired style to the control-input div

Valid codepen for example

Hope this help.
Feel free to suggest solutions I wouldn’t have thought of.