If you’re looking to build an Ethereum dApp, one of the first things you’ll need to do is integrate web3 monitoring into your application. While this may sound complicated, it’s actually quite simple and only requires a few steps.

The first step is to create a new file in your project directory called web3Monitor.js. Next, copy the following code into that file:

var Web3 = require(‘web3’); var web3 = new Web3(new Web3.providers.HttpProvider(“http://localhost:8545”)); var filter = web3.eth.

filter(‘pending’); filter.watch(function(error, result) { if (!error) { console.log(result); } });.

This code creates a connection to an Ethereum node running on your local machine and sets up a filter for pending transactions. Every time a new transaction is detected, the callback function will be triggered and the result will be logged to the console.

Now that we have our monitoring set up, we need to make sure our dApp can actually use it. The easiest way to do this is by using the web3-react library, which provides React bindings for web3.

js.

First, install the library using npm:

npm install –save web3-react

Next, we need to modify our App component to use the library:

import React from ‘react’; import { useWeb3Context } from ‘web3-react’; function App() { const context = useWeb3Context(); if (context.active && !context.error) { // web3 is ready, do something. } else if (context.error) { // handle error. } else { // loading screen.

} } export default App;.

Now that our App component is set up to use web3-react, we can access our Ethereum node via the context object inside of our component functions. For example, we could get the current block number like this:

context.web3 eth.

getBlockNumber().then(console.log); // logs the current block number to the console.

Or we could get the balance of an address like this:

context .web3 .eth .

getBalance(“0x6C1DC62497b1d8b7a70A6822f4f5ae0080a9a872”) .then(console .log ); // logs the balance of 0x6C1DC62497b1d8b7a70A6822f4f5ae0080a9a872 address to the console.

And finally, we could submit a transaction like this:

context .

sendTransaction({ from: “0x6C1DC62497b1d8b7a70A6822f4f5ae0080a9a872”, // sender’s address to: “0xd46e8dd67c5d32be8058bb8eb970870f07244567”, // recipient’s address value: “1000000000000000000” // amount in wei }) .log ); .

That’s all there is to it! With just a few lines of code, you can easily add web3 monitoring to your Ethereum dApp.