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Ethereum Cookbook

You're reading from   Ethereum Cookbook Over 100 recipes covering Ethereum-based tokens, games, wallets, smart contracts, protocols, and Dapps

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Product type Paperback
Published in Aug 2018
Publisher Packt
ISBN-13 9781789133998
Length 404 pages
Edition 1st Edition
Languages
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Author (1):
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Manoj P R Manoj P R
Author Profile Icon Manoj P R
Manoj P R
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Toc

Table of Contents (13) Chapters Close

Preface 1. Getting Started 2. Smart Contract Development FREE CHAPTER 3. Interacting with the Contract 4. The Truffle Suite 5. Tokens and ICOs 6. Games and DAOs 7. Advanced Solidity 8. Smart Contract Security 9. Design Decisions 10. Other Protocols and Applications 11. Miscellaneous 12. Other Books You May Enjoy

Fetching data from APIs using solidity

Ethereum virtual machine (EVM), by design, cannot read data from the outside world. This restricts achieving certain functionalities in Ethereum blockchain. Since every node runs every calculation, it’s not efficient to make arbitrary network requests from an Ethereum contract.

We can overcome this limitation with the help of oracles. These allow a smart contract to read data from an external source in an intelligent way. In this recipe, you will learn to create an Oracle service and read data from an external API.

Getting ready

You need to have a working Ethereum installation for deploying and testing the smart contract. You can also use the Remix IDE to write and test the solidity...

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