document that setFeatureState needs numeric ids

[andrewharvey]

#9559 changed the documentation for setFeatureState which previously read

Features are identified by their id attribute, which must be an integer or a string that can be cast to an integer.

That part was removed, however it appears that string id's don't work when using setFeatureState.

I couldn't find an existing ticket, so short of implementing this so that string id's work, we could better document this limitation.

[geirmarius]

Hey, we're using string IDs without issues in setFeatureState in the latest release version. We're targeting the promoteId which points to a string value in our geojson.

Just wanted to let you know.

[andrewharvey]

Strange I put together a minimal example https://jsfiddle.net/andrewharvey4/1oLj6u8t/3/ and it's not working with string ids.

[geirmarius]

Aha, that makes ... sense. Ids in mapbox cannot be numbers, but you can use promoteId to "promote" another property to use in setFeatureState, and that one can be a string: https://jsfiddle.net/g1wL8q7n/

Not very well documented tho, and I spent hours trying to figure out how to. 😅

[douglasg14b]

Seriously, I just wasted 1/2 a day trying to figure out why setFeatureState wasn't working. Then I found this issue #7986 that states that is accepts strings that can be coerced into numbers. Except that I'm using hexadecimal strings that are numbers just in base 16...

Please fix the document, this was absolutely exhausting.

[asheemmamoowala]

Thanks for the feedback here, I have a small improvement in #10356