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NFT Voucher Library

This is a sub module in the web3 integration module that is utilzied to create and sign the NFT vouchers for the NFT drop and redeem features in the Webaverse app.

const { ClaimableVoucher } = require("./integration/web3/lib");

Usage​

initialize​

const  claimableVoucher = new  ClaimableVoucher({ contract:  contract, signer:  signer });

Initializes an instance of claimableVoucher library

Inputs​

  • Object: {Object} [Required]
    • contract: {object} ethers contract instance
    • signer: {object} ethers signer instance

createVoucher​

let voucher = await  claimableVoucher.createVoucher(tokenID, balance, nonce, timestamp);

Creates a signed voucher of the given token ID using ethers library and returns the instance of it.

Inputs​

  • tokenId: {int|string} [Required] The smart contract generated token ID of the object that is to be dropped in the world
  • balance: {int|string} [Required] Integer value for token balance(NOT APPLICABLE YET i.e. should be "0")
  • nonce: {int|string} [Required]4 bytes random integer
  • timestamp: {int|string} [Required] Unix timestamp that would be stored as an expiry for the NFT drop

Return​

  • voucher: {object} A voucher object signed by the user metamask wallet that contains tokenId, nonce, expiry, and user wallet's signature.

Example​

const  claimableVoucher = new  ClaimableVoucher({ contract:  contract, signer:  signer });
const  tokenID = localStorageSlotIndex;
const  timestamp = Math.round(new  Date().getTime() / 1000) + 1000;
const  nonce = await  ethers.BigNumber.from(ethers.utils.randomBytes(4)).toNumber();
const  balance = 0;
try {
  voucher = await  claimableVoucher.createVoucher(tokenID, balance, nonce, timestamp);
  } catch (err) {
    console.log(err);
   }

Architecture​

Location​

Webaverse App
└───integration
   └───web3
       └───lib

Methods​

createVoucher​

async  createVoucher(tokenId, balance, nonce, expiry) {
    const  voucher = { tokenId, balance, nonce, expiry };
    const  domain = await  this._signingDomain();
    const  types = {
    NFTVoucher: [
       { name:  "tokenId", type:  "uint256" },
       { name:  "balance", type:  "uint256" },
       { name:  "nonce", type:  "uint256" },
       { name:  "expiry", type:  "uint256" },
      ],
     };
    const  signature = await  this.signer._signTypedData(domain, types, voucher);
    return {...voucher, signature};
}