[WIP] Implementation of plugins for ERC165, ERC721 and cryptokitties

[leonprou]

PR for issue #109

[CLAassistant]

All committers have signed the CLA.

[raulk]

Some initial feedback. I think we're off to a very good start!

[raulk]

We prefer strict camel casing.

Suggested change

	supportsInterface(interfaceID: "0x01ffc9a7")
	supportsInterface(interfaceId: "0x01ffc9a7")

[leonprou]

I prefer too, but that's the language of the original EIP - https://github.com/ethereum/EIPs/blob/master/EIPS/eip-165.md. Of course we can do interfaceId, your call.

[raulk]

How about we add a a field an an enum type for known interface IDs?

[leonprou]

as a new grapql method (like supportsInterfaceByEnum) or just at the backend?

[raulk]

We don't want to pollute the global namespace. How about adding a if this plugin extends the Account type with an nftToken field? We'd need to add the token field in the core plugin schema. A query would look like this:

{
  account(address: "0x06012c8cf97BEaD5deAe237070F9587f8E7A266d") {
    contract {
      nftContract {
      }
    }
  }
}

[leonprou]

Interesting, yeah this looks cleaner. But I'm not sure why we need the contract fields as a intermediary (for logical distinction?). For now I did this syntax:

  {
  account(address:"0x6EbeAf8e8E946F0716E6533A6f2cefc83f60e8Ab") {
    nftToken {
      balanceOf(owner: "0xD418c5d0c4a3D87a6c555B7aA41f13EF87485Ec6")
      }
    }    
  }

If I would add the contract to Account, what should it return if plugins are used? An empty object?

[raulk]

This is referencing the ERC20 TokenHolder, right? I think we need to rename TokenHolder to ERC20TokenHolder, and we might need to add a field owns(tokenId: Long) that calls ownerOf on the token ID and returns true if we own it.

[leonprou]

Yes this makes sense. Just didn't want to touch the old code

[leonprou]

about the method owns, what's the proposed graphql sytnax? If it's:

account(address:"0x06012c8cf97BEaD5deAe237070F9587f8E7A266d") {
owns(tokenId: 1)
}

The account address is the address of the token owner or of the token contract?