[Swift] Reference in Object API to underlying type

[jackflips]

Would it be possible to have a reference to the underlying FlatBufferObject type in its generated convenience class?

For example, if I have a Request type, and I pass in --gen-object-api to the FlatBuffer schema compiler, I get a RequestT class. I think it would be really nice to have a reference to the Request type in the RequestT class, so that I could write an extension on RequestT that would let users call serialize() and have it spit out FlatBuffer Data, without having to worry about how FlatBuffers work at all.

[mustiikhalil]

@jackflips thanks for opening the issue. I think the serialize method you are mentioning already exists.

        var monster = Monster.getRootAsMonster(bb: fb)
        readFlatbufferMonster(monster: &monster)
        var unpacked: MyGame_Example_MonsterT? = monster.unpack()
        readObjectApi(monster: unpacked!)
        var builder = FlatBufferBuilder()
        let root = Monster.pack(&builder, obj: &unpacked)

So you can write an extension that does the following:

func serialize() -> Data {} 

[jackflips]

Makes sense! But the serialize extension would have to be on Monster, right? Rather than MonsterT?

[mustiikhalil]

@jackflips.
The extension is going to be on MonsterT, and it would be something like this:

func serialize() -> ByteBuffer {
  var builder = FlatBufferBuilder(initialSize: 64)
  let root = Type.pack(&builder, obj: &self)
  builder.finish(root)
  return builder.sizedBuffer
}

more or less it should look like this, which gives me the idea of actually adding this method to the ObjectApi protocol, instead of letting the users have the control over it.

[jackflips]

On my generated PacketT object (analogous to MonsterT), I don't have a pack function. Pack is a static function on the Packet class. This brings me back to my original question, which is how can I access the Packet class from PacketT to use Pack? Your example seems to imply that pack is a function on MonsterT.

more or less it should look like this, which gives me the idea of actually adding this method to the ObjectApi protocol, instead of letting the users have the control over it.

That's a great idea.

[mustiikhalil]

so, pack is indeed a Monster static function, and you can't access it through MonsterT. since if you see the example let root = Monster.pack(&builder, obj: &new_T_object) we pack the new_T_object by passing it with the builder into that function. So the object Api objects don't hold any reference to the original buffer since they are unpacked objects, however, you can pack them back to a new buffer by using the pack function. I will add a wrapper function to ease the transition for that.

[jackflips]

however, you can pack them back to a new buffer by using the pack function. I will add a wrapper function to ease the transition for that.

I'm confused about this. How am I supposed to call the pack function from an extension on NativeTable? I see the ObjectAPI protocol definition in the FlatBufferObject.swift file but it doesn't seem like any of the generated code conforms to this protocol.

[mustiikhalil]

@jackflips I created the PR, you can take a look at the solution there. plus if you want it urgently you can adapt that solution into your own extension.

[jackflips]

Thank you!