Question: combobox item callback

[ptmdmusique]

Question

Is there anyway we can expose something like a isValid callback for calcite-combobox-item or calcite-combobox so we can validate the item the user adds before actually add it to the combobox ❓

We're having a tag list feature for items and one of the issue came up is that tags that have trailing/leading spaces are considered as separated tags. So, I think having a callback to validate the tag before adding it to the combobox would be the solution in the long run

cc @paulcpederson

[driskull]

We can probably add a property to do this:

  /**
   * When provided, this method will be called before a custom value is added. 
   * Depends on 'allowCustomValues' being true.
   */
  @Prop() beforeAddCustomValue?: () => Promise<void>;

What do you think @paulcpederson ?

[paulcpederson]

This is a nice approach!

I would change the promise signature slightly so that the resolved value is what we use for the custom value. That way a dev could transform things if need be (ie escape certain chars, dedupe things, etc). If resolved with a falsey value this could stop the addition entirely?

@Prop() beforeAddCustomValue?: (customValue: string) => Promise<string|false>;

or something like that.