custom field - multiselect field predefined and new values?

Hi,

You need first to add the values you want to use in the custom field settings. There is no option to add new values from the form where the field is being used.

Hello,

Since the creation of a product custom field or an item custom field result to the alteration of the database ; we cannot authorize a vendor to create them.

But in HikaShop, it is possible to have item custom field with dynamic values.
You can create one dropdown item field (like "dynamic_field") and one text product field with the suffix "_values" (so "dynamic_field_values").
But letting the item field values empty, HikaShop will use what is stored in the product custom field for the display of the item field.
The data in the product field need to be formatted as the dropdown data is stored into your database : the value, "::" and the text. And you will have one entry per line.

That feature is a bit technical but is currently used in a few websites.
Afterwards, it is still possible to use a plugin to create a new kind of type so the vendor would have a nice interface to configure the dropdown values instead than a raw text box with specific format.

Regards,