Book Image

Hands-On Blockchain with Hyperledger

By : Nitin Gaur, Luc Desrosiers, Venkatraman Ramakrishna, Petr Novotny, Salman A. Baset, Anthony O'Dowd
Book Image

Hands-On Blockchain with Hyperledger

By: Nitin Gaur, Luc Desrosiers, Venkatraman Ramakrishna, Petr Novotny, Salman A. Baset, Anthony O'Dowd

Overview of this book

Blockchain and Hyperledger technologies are hot topics today. Hyperledger Fabric and Hyperledger Composer are open source projects that help organizations create private, permissioned blockchain networks. These find application in finance, banking, supply chain, and IoT among several other sectors. This book will be an easy reference to explore and build blockchain networks using Hyperledger technologies. The book starts by outlining the evolution of blockchain, including an overview of relevant blockchain technologies. You will learn how to configure Hyperledger Fabric and become familiar with its architectural components. Using these components, you will learn to build private blockchain networks, along with the applications that connect to them. Starting from principles first, you’ll learn to design and launch a network, implement smart contracts in chaincode and much more. By the end of this book, you will be able to build and deploy your own decentralized applications, handling the key pain points encountered in the blockchain life cycle.
Table of Contents (20 chapters)
Title Page
Copyright and Credits
Packt Upsell

Implementing chaincode functions

At this point, we now have the basic building blocks of chaincode. We have the Init method, which initiates the chaincode and the Invoke method, which receives request from the client and the access control mechanism. Now, we need to define the functionality of the chaincode.

Based on our scenario, the following tables summarize the list of functions that record and retrieve data to and from the ledger to provide the business logic of the smart contract. The tables also define the access control definitions of organization member, which are needed in order to invoke the respective functions.

The following table illustrates the chaincode modification functions, that is, how to record transactions on the ledger:

Function name

Permission to invoke




Requests a trade agreement



Accepts a trade agreement



Requests a letter of credit



Issues a letter of credit



Accepts a letter of...