C#: Add PropertyHint.Enum support to Array<StringName>

[magian1127]

Previously, only StringName was supported but not Array<StringName>, now it has been added.

    [Export(PropertyHint.Enum, "a,b,c")]
    public Godot.Collections.Array<StringName> Tests

[RedworkDE]

Works as expected, code change looks good.

[akien-mga]

Out of curiosity, is this feature supported in GDScript? I don't see it in the docs / can't find intuitively how to use it for an Array[String] or Array[StringName].

[RedworkDE]

I don't think it is, beyond manually defining an appropriate PROPERTY_HINT_TYPE_STRING for a property using _get_property_list.

Edit: gdscript doesn't even support the enum annotation on StringName.

[magian1127]

gds 3.5 export support Array[String] .
4.x ......

[raulsntos]

GDScript doesn't support this, but there's an open PR:

• GDScript: Add array support to @export_enum annotation #72951.

It seems to support Array[int], Array[String] and Array[T] where T is an enum.
But it doesn't seem to support Array[StringName]. It may be an oversight, specially since String and StringName are pretty much interchangeable in GDScript, I'd expect both to be supported.

Personally, I think it'd be best to merge GDScript support first, and make the C# implementation sync with that. My biggest concern is to deviate too much from whatever GDScript ends up doing.

[dalexeev]

It seems to support Array[int], Array[String] and Array[T] where T is an enum.

I don't know how applicable this is to C#, but I'll mention it here for completeness. In the PR, Array[Enum] is not supported by the @export_enum annotation, it makes no sense and is confusing. Array[int] is for values, Array[String] and Array[StringName] are for keys. Array[Enum] is supported by the @export annotation, for which you don't need to list options as annotation arguments.

[raulsntos]

Thanks for the explanation! We don't have an [ExportEnum] attribute in C#, what we have is [Export] which is similar to the @export_custom annotation¹, but when used without parameters it works like @export (no need to provide a list of values for enum arrays).

If/when we implement an [ExportEnum] attribute I assume it will work like @export_enum.

When [Export] is used with PropertyHint.Enum and an Array[Enum] property, I agree it can be confusing, but it just creates the PropertyInfo with the hint and hint_string as specified. So it's up to Core whether those hints work or not, we don't touch them².

Footnotes

1. Yet another unmerged GDScript PR about export annotations: https://github.com/godotengine/godot/pull/72912 ↩

2. We do actually touch them a little bit, to format the hint_string as {ARRAY_ELEMENT_TYPE}/{PROVIDED_HINT}:{PROVIDED_HINT_STRING}. ↩

[YuriSizov]

Personally, I think it'd be best to merge GDScript support first, and make the C# implementation sync with that. My biggest concern is to deviate too much from whatever GDScript ends up doing.

So it looks like there are already deviations. [ExportEnum] does not exist, and [Export] doesn't work like @export but rather like a not-yet-implemented @export_custom or just manually crafted property definitions. So it seems to me that this PR doesn't make the situation worse and less in line than the implementation already is.

What do you think @raulsntos @RedworkDE @neikeq, should we merge this now then?

[RedworkDE]

I don't see how this can conflict with any future plans we may end up having, unless these plans break the behavior of the existing Array<string> support, in which case breaking the behavior of Array<StringName> as well doesn't make the change any bigger of a deal; so I would merge this.

[raulsntos]

I'm also fine with merging this. Since we already support Array<string> it's not too far-fetched to also support Array<StringName>.

My biggest concerns were addressed by @dalexeev, it seems we want to support Array[String] and Array[StringName] with @export_enum in GDScript too, so it feels like this matches.

[YuriSizov]

Let's merge it then. Thanks!