Book Image

Advanced Blockchain Development

By : Imran Bashir, Narayan Prusty
Book Image

Advanced Blockchain Development

By: Imran Bashir, Narayan Prusty

Overview of this book

Blockchain technology is a distributed ledger with applications in industries such as finance, government, and media. This Learning Path is your guide to building blockchain networks using Ethereum, JavaScript, and Solidity. You will get started by understanding the technical foundations of blockchain technology, including distributed systems, cryptography and how this digital ledger keeps data secure. Further into the chapters, you’ll gain insights into developing applications using Ethereum and Hyperledger. As you build on your knowledge of Ether security, mining, smart contracts, and Solidity, you’ll learn how to create robust and secure applications that run exactly as programmed without being affected by fraud, censorship, or third-party interference. Toward the concluding chapters, you’ll explore how blockchain solutions can be implemented in applications such as IoT apps, in addition to its use in currencies. This Learning Path also highlights how you can increase blockchain scalability, and discusses the future scope of this fascinating and powerful technology. By the end of this Learning Path, you'll be equipped with the skills you need to tackle pain points encountered in the blockchain life cycle and confidently design and deploy decentralized applications.
Table of Contents (25 chapters)
Title Page
Copyright and Credits
About Packt
Contributors
Preface
15
Blockchain - Outside of Currencies
16
Scalability and Other Challenges
Index

Chapter 12. Building a Betting App

Sometimes, it is necessary for smart contracts to access data from other dapps or from the World Wide Web. But it's really complicated to let smart contracts access outside data due to technical and consensus challenges. Therefore, currently, Ethereum smart contracts don't have native support to access outside data. But there are third-party solutions for Ethereum smart contracts to access data from some popular dapps and from the World Wide Web. In this chapter, we will learn how to use Oraclize to make HTTP requests from Ethereum smart contracts to access data from the World Wide Web. We will also learn how to access files stored in IPFS, use the strings library to work with strings, and so on. We will learn all this by building a football-betting smart contract and a client for it.

In this chapter, we'll cover the following topics:

  • How does Oraclize work?
  • What are Oraclize's various data sources and how do each of them work?
  • How does consensus work in Oraclize...