docs/building-with-ocean/using-ocean-libraries/update-metadata.md

Update metadata

This tutorial will guide you to update an existing asset published on-chain using Ocean libraries. The tutorial assumes that you already have the did of the asset which needs to be updated. In this tutorial, we will update the name, description, tags of the data NFT. Please refer the page on DDO to know more about additional the fields which can be updated.

Configuration

See this guide on defining a .env file and a configuration file

Create a script to update the metadata

Create a new file in the same working directory where configuration file (config.py/config.js) and .env files are present, and copy the code as listed below.

{% tabs %} {% tab title="ocean.js" %} {% code title="updateMetadata.js" %}

const {
  Nft,
  ProviderInstance,
  getHash,
  Aquarius
} = require('@oceanprotocol/lib');
const { SHA256 } = require('crypto-js');
const Web3 = require('web3');
const { web3Provider, oceanConfig } = require('./config');

const web3 = new Web3(web3Provider);
const aquarius = new Aquarius(oceanConfig.metadataCacheUri);
const nft = new Nft(web3);
const providerUrl = oceanConfig.providerUri;

// replace the did here
const did = "did:op:a419f07306d71f3357f8df74807d5d12bddd6bcd738eb0b461470c64859d6f0f";

const setMetadata = async (did) => {
  const accounts = await web3.eth.getAccounts();
  const publisherAccount = accounts[0];

  const ddo = await aquarius.resolve(did);

  // update the ddo here
  ddo.metadata.name = "Sample dataset v2";
  ddo.metadata.description = "Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam";
  ddo.metadata.tags = ["new tag1", "new tag2"];

  providerResponse = await ProviderInstance.encrypt(ddo, providerUrl);
  const encryptedResponse = await providerResponse;
  const metadataHash = getHash(JSON.stringify(ddo));

  await nft.setMetadata(
    ddo.nftAddress,
    publisherAccount,
    0,
    providerUrl,
    '',
    '0x2',
    encryptedResponse,
    `0x${metadataHash}`
  );

  await aquarius.waitForAqua(ddo.id);

  console.log(`Resolved asset did [${ddo.id}]from aquarius.`);
  console.log(`Updated name: [${ddo.metadata.name}].`);
  console.log(`Updated description: [${ddo.metadata.description}].`);
  console.log(`Updated tags: [${ddo.metadata.tags}].`);

};

setMetadata(did).then(() => {
  process.exit();
}).catch((err) => {
  console.error(err);
  process.exit(1);
});

{% endcode %}

Execute the script

node updateMetadata.js

{% endtab %} {% endtabs %}