Open-Attestation Token

This library facilitates ERC721 Token interactions using OpenAttestation wrapped documents as token identifiers. EthersJS is heavily used in this library and unless otherwise stated all Ethereum-related interfaces are expected to be derived from EthersJS.

Install

    $ npm install @govtechsg/oa-token or yarn @govtechsg/oa-token

Initialize

    import { ReadOnlyToken, WriteableToken } from "@govtechsg/oa-token";
    const tokenInstance = new ReadOnlyToken({document: wrappedDocument});

Save Web3 Provider or Wallet

    import { WriteableToken, setWeb3Provider, setWallet } from "@govtechsg/oa-token";

    setWeb3Provider(provider)
    setWallet(wallet)

    const token = new WriteableToken({document}) // Don't need to provider wallet or provider again here

Get the owner of the contract

    await tokenInstance.getOwner();

returns a promise for a class instance that allows interaction with the owner of the token.

Types of Owners

EthereumAccountOwner

EthereumAccountOwner are simply objects with a .address property. This owner class is instantiated when the owner of the Token is simply an externally owned Ethereum Account - i.e, not a smart contract.

TitleEscrowOwner

TitleEscrowOwner is instantiated when the owner of the Token is a TitleEscrow smart contract, which governs the transfer of ownership according to UN/MLETR.

It allows the reading of the properties, holder and beneficiary.

Usage:

const tokenInstance = new ReadOnlyToken({document: wrappedDocument});
const tokenOwner = tokenInstance.getOwner()

if (tokenOwner.isTitleEscrow()) {
   const beneficiary = tokenOwner.beneficiary();
   const holder = tokenOwner.holder();

   console.log(
     `Token ID: ${
       Token.tokenId
     } is owned by TitleEscrow at ${tokenOwner.address}. Has beneficiary ${beneficiary} and held by ${holder}`
   );
 } else {
   console.log(`Token ID: ${Token.tokenId}, owned by ${tokenOwner.address}`);
}

WriteableTitleEscrowOwner

WriteableTitleEscrowOwner is the writeable extension of TitleEscrowOwner, it allows for calling the smart contract functions which change the state of the system, in addition to everything TitleEscrowOwner has.

It has the additional methods changeHolder(newHolder: EthereumAddress), endorseTransfer(newBeneficiary: EthereumAddress) , transferTo(newBeneficiary: EthereumAddress), mint(to: EthereumAddress).

There are also additional helper methods to make a transfer or mint to a new TitleEscrow contract transferToNewEscrow(beneficiary: EthereumAddress, holder: EthereumAddress) and mintToEscrow(beneficiary: EthereumAddress, holder: EthereumAddress). These methods first deploy a TitleEscrow contract then executes the transfer or mint function to that TitleEscrow's address.

These methods all return a promise that resolves to the transaction hash when the transaction has been confirmed.

Usage:

const writeableTokenInstance = new WriteableToken({document: wrappedDocument, web3Provider, wallet})
const tokenOwner = writeableTokenInstance.getOwner()

const transactionHash = await tokenOwner.changeHolder(newHolder);

Transfer the token ownership

Writeable token instance initialisation requires an EthersJS type wallet that has write permissions for that token.

    const writeableTokenInstance = new WriteableToken({document: wrappedDocument, web3Provider, wallet})
    await token.transferOwnership("NEW_OWNER_ADDRESS");

returns a transaction hash after the transaction has been mined.

Development

Logging

Turn on debugging by using the DEBUG environment variable for Node.js and using localStorage.debug in the browser.

E.g:

DEBUG="PLACEHOLDER_PROJECT_NAME:*" npm run dev

Commit message format

This boiler plate uses the semantic-release package to manage versioning. Once it has been set up, version numbers and Github release changelogs will be automatically managed. semantic-release uses the commit messages to determine the type of changes in the codebase. Following formalized conventions for commit messages, semantic-release automatically determines the next semantic version number, generates a changelog and publishes the release.

Use npm run commit instead of git commit in order to invoke Commitizen commit helper that helps with writing properly formatted commit messages.

API

Table of Contents

License

MIT © Sumit Chaudhari