Fire specific event if allowUserOptions was used to create a new option

[janosh]

Discussed in #262

^{Originally posted by igorlanko September 11, 2023}
It might be useful if you want to modify the list of tags by POSTing a request to create one.

In my context, I'd need to differentiate between updating a PGSQL table with new item-tag relation link in a many-to-many table, and creating a new tag in the tags table.

What do you think?

[janosh]

@igorlanko Sounds good, happy to take a PR for that. You'd start by adding a new DispatchEvent key

svelte-multiselect/src/lib/types.ts

Lines 19 to 25 in c4150c9

	export type DispatchEvents<T = Option> = {
	add: { option: T }
	create: { option: T }
	remove: { option: T }
	removeAll: { options: T[] }
	change: {
	option?: T

and then modifying the add function to check if it's an addition that required allowUserOptions

svelte-multiselect/src/lib/MultiSelect.svelte

Lines 198 to 200 in c4150c9

	}
	dispatch(`create`, { option })
	}