Hide calendar if no booking slots are available

Thanks, it works as expected.

With these changes the month selector does not appear if the prev month the current has no slots.
In this way you cannot select a next months.

Example:
Start date: April 10th
End date: June 28th
Current date: May 11th

I can confirm luca_cracco’s comment. If the start date is in the previous month, the daysData variable remains empty.
Consequently, the condition if (!daysData || daysData.length === 0) is triggered, resulting in the display of the no-slots-message.

I created two new branches.
The first one contains changes that fix the issue where the calendar is hidden when the start date is in a past month.

As a workaround, I added a month selection because otherwise, the bookable days were not displayed on page load.
If someone can solve it without the selection, feel free to change it. However, it would be good to keep my workaround as an option.

The second branch is identical functionwise, but now it no longer uses jQuery, only pure JavaScript.
I did this because Drupal Core is trying to deprecate jQuery.
https://www.drupal.org/project/drupal/issues/3052002 🌱 [meta] Replace JQuery with vanilla Javascript in core Active

@rfmarcelino
Could you reopen the issue and change the status to Needs review?

Thank you @hewi1345
Yes, I also considered using plain js.
From my tests, the code in both branches seem to need some work:

I worked on the vanilla js branch.

I tried another approach and the code now removes the month without available slots from the select list.
If this would an option we would not need the "no slots available" message anymore or?

However the code still needs some work. I am not so familiar with the core/once implementation.
If two webforms are placed on a page with the same booking field id the second form does not work.

Thank you for your work!
I committed the plain js version with some changes.
From my tests it worked but I didn't made a release tag yet since I want to do some more testing and eventualy also send the webform settings validation in plain js.
Meanwile, feel free to play around with it and give your feedback.

I want to do some more testing

That would be good.

and eventualy also send the webform settings validation in plain js.

Do you mean the validation on the config form?

Take a look at Use form validation instead of custom js for exclusion dates and time intervals 📌 Use form validation instead of custom js for exclusion dates and time intervals Needs review