Beginning Ethereum Smart Contracts Programming: With Examples in Python, Solidity, and JavaScript

by Wei-Meng Lee

Overview

Use this book to write an Ethereum Blockchain Smart Contract, test it, deploy it, and create a web application to interact with your smart contract.


Beginning Ethereum Smart Contracts Programming is your fastest and most efficient means of getting started if you are unsure where to begin and how to connect to the Ethereum Blockchain. The book begins with a foundational discussion of blockchain and the motivation behind it. From there, you will get up close and personal with the Ethereum Blockchain, learning how to use an Ethereum client (geth) to connect to the Ethereum Blockchain to perform transactions such as sending Ethers to another account.


You will learn about smart contracts without having to wade through tons of documentation. Author Lee’s “learn-by-doing” approach will allow you to be productive and feel confident in your ability in no time. The last part of this book covers tokens, a topic that has taken the cryptocurrency market by storm.


Sample code in Python is provided in the book and online. C# samples are provided online.




What You'll Learn

• Understand the basic premise of blockchain and “record keeping” in a peer-to-peer network
  
• Experience blockchain in action by creating your own blockchain using Python and C#
  
• Know the foundation of smart contracts programming and how to deploy and test smart contracts
  
• Read a case study to illustrate the use of blockchain
  
• Be familiar with tokens, and how to create and launch your own ICO digital token
  
• Write smart contracts that transact using tokens
  

Who This Book Is For


Those who want to get started quickly with Ethereum Smart Contracts programming. Basic programming knowledge and an understanding of Python or C# is recommended.

Product Details

ISBN-13:	9781484250853
Publisher:	Apress
Publication date:	09/06/2019
Edition description:	1st ed.
Pages:	293
Sales rank:	1,083,740
Product dimensions:	6.90(w) x 9.80(h) x 0.60(d)

About the Author

Wei-Meng Lee is the founder of Developer Learning Solutions, a technology company specializing in hands-on training of blockchain and other emerging technologies. He has many years of training expertise and his courses emphasize a learn-by-doing approach. He is a master at making learning a new programming language or technology less intimidating and fun. He can be found speaking at conferences worldwide such as NDC and he regularly contributes to online and print publications such as DevX.com, MobiForge.com, and CoDe Magazine. He is active on social media on his blog learn2develop.net, on Facebook at DeveloperLearningSolutions, on Twitter @weimenglee, and on LinkedIn at leeweimeng.

Table of Contents

Chapter 1. What is Blockchain?

We start with the motivations of Blockchain - the trust issues we face today and how we can solve that using decentralization. We will use a real-life example to bring about the discussion. Next, we will talk about Blockchain and how it fits into the decentralized model. By the end of this chapter readers would have a pretty solid understanding of the main Blockchain terminologies, such as mining, PoW, Merkele Tree/Root, etc.

Trust Today

Placement of Trusts

Centralization - Problems with Trust Today

Solving Trust Issues with Decentralization

Blockchain - A Huge Chain of Blocks

Chaining usng Hashing Functions

Assembling the Transactions

Mining the Blocks using Proof of Work

Structure of a Blockchain

Blockheaders

Merkle Tree and Root

Types of Nodes

Confirmations

Consensus

Rewards for Mining

Chapter 2. Implementing Your Own Blockchain

This chapter basically reinforces the concept covered in Chapter 1. By implementing your own Blockchain, it makes it very useful to understand concepts like transactions, mining, consensus, etc. Here, we implement the blockchains using Python and C#.

Implementing your own Blockchain using Python

Implementing your own Blockchain using C#

Chapter 3. Connecting to the Ethereum Blockchain

For this book, I will primarily use geth, an Ethereum client, to connect to the Ethereum blockchain. Readers will learn how to download and install geth, and use it to connect to the various Ethereum blockchains (mainnet, testnet, etc). Readers will learn about the various sync modes - fast, full, and light.

Installing Geth

Getting Started with Geth

Connecting to the various Ethereum Blockchains

Syncing with the Ethereum Blockchain

Chapter 4. Creating Your Private Ethereum Test Network

One feature of geth is that you can use it to create your own private test network, without connecting to the real blockchain. This makes development work much easier, and allow you to explore the Ethereum blockchain without needing to acquire ether.

Creating the Genesis Block

Creating a folder for storing Blockchain Data

Initiating a Blockchain Node

Starting Nodes

Creating Accounts

Checking the Balance of an Account

Ethereum Units

Pairing the Nodes

Performing Mining

Transferring Ethers between Nodes

Chapter 5. Using the Metamask Chrome Extension

In order to connect to the Ethereum blockchain to deploy and consume contracts, you need to hold Ether. An easy way would be to use the MetaMask Chrome extension. The MetaMask Chrome Extension is an Ethereum wallet. This chapter will show how you can use it to obtain Ethers for testing on the Ethereum testnet.

What is MetaMask?

Creating Accounts

Recovering Accounts

Getting Ethers

Transferring Ethers

Connecting MetaMask to Geth

Chapter 6. Introduction to Smart Contracts

Now that readers are familiar with the Ethereum blockchain, it is now time to explore the most exciting feature of it - Smart Contracts. Smart contracts are written using the Solidity programming language. This chapter goes through the syntax of the language and explores the most salient parts of the language.

Solidity

Hello, Solidity

Comments

Data Types

Integer Literals

Ether and Time Units

Arrays

Structures

Enums

State Variables

Control Structures

Functions

Fallback Functions

Special Variable

Cryptographic Functions

Inheritance

Modifiers and Events

Storage Layout

Chapter 7. Developing and Deploying Smart Contracts

This chapter dives into the details of developing and deploying the Smart contract using the Remix IDE. It also discusses how Smart Contracts can be called and tested from the command line.

Using the Remix IDE

Application Binary Interface (ABI)

Bytecode

Deploying the Smart Contract onto an Ethereum Node using Geth

Invoking the Contract from a Local Node

Invoking the Contract from a Another Node

Calling a Smart Contract from Another

Deploying a Contract Dynamically

Chapter 8. Testing Smart Contracts using ganache

Another tool that is useful for Smart Contract developers is Ganache. Ganache simulates an Ethereum network, and it comes with 10 pre-created accounts each credited with 100 Ethers. Using Ganache, developers can deploy their smart contract without needing to connect to the real Ethereum network.

What is ganache (formerly testrpc)?

Installing ganache

Deploying Smart Contracts to ganache

Connecting MetaMask to ganache

Importing the accounts in ganache into MetaMask

Chapter 9. Using the Web3.js API

Once a Smart contract is deployed, how does the end user use it? In this chapter, readers will learn how to use the Web3.js APIs in their Web application to consume Smart contracts. Readers will learn how Web3.js works and the techniques for connecting to the different Ethereum in the background.

What is Web3.js?

Installing Web3.js

Consuming a contract using Web3.js

Loading the page using file:///

Loading the page using http://

Chapter 10. Smart Contract Events

When a Smart Contract has finished performing a task, how does it inform the user? This is achieved using events. In this chapter, readers will extend some of the contracts developed in the earlier chapters to use events to extend the usefulness of the application.

What are events?

Defining events in your contract

Handling events in your web Application

Chapter 11. Project – Online Lottery

Now that readers have learned all the fundamental building blocks of blockchain, it is now time to put them into a working example. This chapter implements an online betting system using Smart Contracts.

How the Game Works

Creating the contract

Testing the Contract using the Remix IDE

Creating the Web Frontend

Testing the App

Chapter 12. Creating Your Own ERC20 Tokens

ICOs are all the rage these days! This bonus chapter talks about tokens and how you can create tokens using Smart Contracts. Once readers have learned how to create tokens, I will show them how to use tokens to pay for services in Smart Contracts.

What are Tokens?

Tokens Standards - ERC20 and ERC223

Creating Token Contracts

Deploying the Token Contracts

Adding Tokens to MetaMask

Paying for Smart Contracts using Tokens