ERC998 Composable NFT

Composing ERC721 with ERC20 into semi fungible token. Seems to be similar to ERC1155. Composability of the NFTs as crypto revolution of non fungibles.

Simple explanation

Selling the part of a parcel that has the biggest value. This contract is breaking down single NFT contract into more items and alllows you to set higher price on the value of the contract itself. Imagine a land with house, the hiuse have bigger value than the land itself so you are able to set higher price for the house and lower for the land.

Adding children to the NFT: Parent -> ERC998 Children -> ERC721

ERC998 requires mapping from the parent [[tokenID]] of the composable to another mapping between child contract address and signer
Child tokens are only able to be transferred from the contract if the sender also owns the parent token ID.
You MUST trust the composable ERC-998 contract does not also have the ability to arbitrarily transfer child tokens the contact technically owns.

Requirements

ERC998 contract requires approval from the ERC721 token in order to use the "transferFrom" (owner, to, 'tokenId') function

Fuctions

You can transfer ERC721 to ERC223 Token Standard using bytes field to indicate which NFT in the ERC998 you wish to transfer to
The sender of the function call owns the parent token, a standard method in the ERC-721 specification implemented as _owns(address, tokenId)
Implemented 'rootOwnerOf' which will actually check who owns the parent token ID all the way up the tree if there is a hierarchy of composable tokens
The parent token ID is mapped to the child token ID through the child contract address, enforcing the parent child relationship

Once these are OK, we can call the transfer function of the child contract and if our transfer is successful we set the children mapping to 0 reflecting that the child asset is no longer owned by the parent asset. This is called decomposing the asset.

Use case

Food or breeding functions of cryptokitties
Aavegotchi
Legal
Supply chain provenance
Virtual assets

ERC998 Composable NFT

Simple explanation

Requirements

Fuctions

Use case

Further reading

ERC998 Composable NFT

Simple explanation

Requirements

Fuctions

Use case

Further reading