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 getAddressData method

We'll build a new method on the blockchain prototype, called getAddressData, and we'll use this method inside of the /address/:address endpoint to fetch the data for a specific address that we are searching for:

  1. Let's build this new method inside of the blockchain.js file. After the getTransaction method, define the getAddressData method as follows:
Blockchain.prototype.getAddressData = function(address) {

});
  1. Now, the first thing that we want to do inside of this method is to get all of the transactions that are associated with the address and put them into a single array. Let's define that array now:
Blockchain.prototype.getAddressData = function(address) {
const addressTransactions = [];
});
  1. Then, we want to cycle through all of the transactions inside of the blockchain. If any of those blocks have the address...