Book Image

Blockchain Development with Hyperledger

By : Salman A. Baset, Luc Desrosiers, Nitin Gaur, Petr Novotny, Anthony O'Dowd, Venkatraman Ramakrishna, Weimin Sun, Xun (Brian) Wu
Book Image

Blockchain Development with Hyperledger

By: Salman A. Baset, Luc Desrosiers, Nitin Gaur, Petr Novotny, Anthony O'Dowd, Venkatraman Ramakrishna, Weimin Sun, Xun (Brian) Wu

Overview of this book

Blockchain and Hyperledger are open source technologies that power the development of decentralized applications. This Learning Path is your helpful reference for exploring and building blockchain networks using Ethereum, Hyperledger Fabric, and Hyperledger Composer. Blockchain Development with Hyperledger will start off by giving you an overview of blockchain and demonstrating how you can set up an Ethereum development environment for developing, packaging, building, and testing campaign-decentralized applications. You'll then explore the de facto language Solidity, which you can use to develop decentralized applications in Ethereum. Following this, you'll be able to configure Hyperledger Fabric and use it to build private blockchain networks and applications that connect to them. Toward the later chapters, you'll learn how to design and launch a network, and even implement smart contracts in chain code. By the end of this Learning Path, you'll be able to build and deploy your own decentralized applications by addressing the key pain points encountered in the blockchain life cycle. This Learning Path includes content from the following Packt products: • Blockchain Quick Start Guide by Xun (Brian) Wu and Weimin Sun • Hands-On Blockchain with Hyperledger by Nitin Gaur et al.
Table of Contents (25 chapters)
Title Page
Copyright
About Packt
Contributors
Preface
Index

Decentralized application overview


A decentralized application (or DApp) is an application that uses smart contracts to run. Smart contracts are deployed on the Ethereum virtual machine (EVM). It is similar to a client-server low-tier architecture. A DApp can have a frontend (web) that makes calls to its backend (smart contract) through the web3.js API.

 

The following structure is what we are going to build for our crowdfunding DApp:

Strucuture of what we will be building for crowdfunding DApp

web3.js quick overview

web3.js is an Ethereum JavaScript API, that provides a collection of libraries to interact with a local or remote Ethereum network. The connection between web3js and Ethereum is made by using the HTTP or IPC protocol. In the following table, we quickly review a number of important web3.js API concepts:

API reference

Description

Example

web3-eth

This package provides an API to interact with the Ethereum blockchain and smart contracts

getBalancesendTransaction, coinbasegetBlockNumber...