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

Case study – crowdfunding campaign


In this section, we will implement and deploy the smart contract for the crowdfunding campaign use case.

The idea of crowd funding is a process of raising funds for a project or venture from the masses. Investors receive tokens that represent a share of the startup they invested. The project sets up a predefined goal and a deadline for reaching it. Once a project misses the goal, the investments are returned, which reduces the risk for investors. This decentralized fundraising model can supplant the fund need for startup, and there is no need for a centralized trusted platform. Investors will only pay the gas fees if the fund returns. Any project contributor gets a token, and they can trade, sell, or keep these tokens. In a certain stage, the token can be used in exchange for real products as the physical reward.

Define struct and events, shown as follows:

pragma solidity ^0.4.24;

contract CrowdFunding {

    Project public project;
    Contribution[] public...