Book Image

Learn Blockchain Programming with JavaScript

By : Eric Traub
Book Image

Learn Blockchain Programming with JavaScript

By: Eric Traub

Overview of this book

Learn Blockchain Programming with JavaScript begins by giving you a clear understanding of what blockchain technology is. You’ll then set up an environment to build your very own blockchain and you’ll add various functionalities to it. By adding functionalities to your blockchain such as the ability to mine new blocks, create transactions, and secure your blockchain through a proof-of-work you’ll gain an in-depth understanding of how blockchain technology functions. As you make your way through the chapters, you’ll learn how to build an API server to interact with your blockchain and how to host your blockchain on a decentralized network. You’ll also build a consensus algorithm and use it to verify data and keep the entire blockchain network synchronized. In the concluding chapters, you’ll finish building your blockchain prototype and gain a thorough understanding of why blockchain technology is so secure and valuable. By the end of this book, you'll understand how decentralized blockchain networks function and why decentralization is such an important feature for securing a blockchain.
Table of Contents (10 chapters)

Building the /receive-new-block endpoint

The next thing that we're going to do is build the /receive-new-block endpoint that we use in the updated /mine endpoint. Let's get started on building the endpoint:

  1. In the dev/networkNode.js file, before the /register-and-broadcast-node endpoint, define the /receive-new-block endpoint as follows:
app.post('/receive-new-block', function(req, res) {
};
  1. Inside this endpoint, the code expects to receive a new block that is being broadcast. Let's save that new block in a variable, as highlighted in the following code:
app.post('/receive-new-block', function(req, res) {
const newBlock = req.body.newBlock;

};
  1. When all of the other nodes receive this new block, they need to check whether it's actually a real block and whether it fits into the chain properly. To verify this, the previousBlockHash...