Book Image

Blockchain Developer's Guide

By : Brenn Hill, Samanyu Chopra, Paul Valencourt, Narayan Prusty
Book Image

Blockchain Developer's Guide

By: Brenn Hill, Samanyu Chopra, Paul Valencourt, Narayan Prusty

Overview of this book

Blockchain applications provide a single-shared ledger to eliminate trust issues involving multiple stakeholders. It is the main technical innovation of Bitcoin, where it serves as the public ledger for Bitcoin transactions. Blockchain Developer's Guide takes you through the electrifying world of blockchain technology. It begins with the basic design of a blockchain and elaborates concepts, such as Initial Coin Offerings (ICOs), tokens, smart contracts, and other related terminologies. You will then explore the components of Ethereum, such as Ether tokens, transactions, and smart contracts that you need to build simple DApps. Blockchain Developer's Guide also explains why you must specifically use Solidity for Ethereum-based projects and lets you explore different blockchains with easy-to-follow examples. You will learn a wide range of concepts - beginning with cryptography in cryptocurrencies and including ether security, mining, and smart contracts. You will learn how to use web sockets and various API services for Ethereum. By the end of this Learning Path, you will be able to build efficient decentralized applications. This Learning Path includes content from the following Packt products: • Blockchain Quick Reference by Brenn Hill, Samanyu Chopra, Paul Valencourt • Building Blockchain Projects by Narayan Prusty
Table of Contents (37 chapters)
Title Page
Copyright
About Packt
Contributors
Preface
Index

Building a wallet service


Now we have learned enough theory about LightWallet, it's time to build a wallet service using LightWallet and hooked-web3-provider. Our wallet service will let users generate a unique seed, display addresses, and their associated balance, and finally, the service will let users send ether to other accounts. All the operations will be done on the client side so that users can trust us easily. Users will either have to remember the seed or store it somewhere.

Prerequisites

Before you start building the wallet service, make sure that you are running the geth development instance, which is mining, has the HTTP-RPC server enabled, allows client-side requests from any domain, and finally has account 0 unlocked. You can do all these by running this:

geth --dev --rpc --rpccorsdomain "*" --rpcaddr "0.0.0.0" --rpcport "8545" --mine --unlock=0

Here, --rpccorsdomain is used to allow certain domains to communicate with geth. We need to provide a list of domains space separated...