Ethereum, tokens & smart contracts.

Notes on getting started : Part 12. Some advanced considerations.

Previous notes in case you are just joining us:
Part 1. Setting up.
Part 2. Web3.js/node.
Part 3. Solidity.
Part 4. Smart Contracts.
Part 5. Smarter Contracts.
Part 6. Tokens & Inheritance.
Part 7. ERC20 Token Standard.
Part 8. Crowdfunding and ICOs.
Part 9. Dapps & MetaMask.
Part 10. Remix, Truffle, TestRPC.
Part 11. Some intermediate considerations.

You made it ! this is the last set of notes on getting started with ehereum, tokens & smart contracts, before leaving I would like to touch on a few more advanced topics, some are somehow abstract and part of the business part and some are code, let’s look at them.

What the heck is an oracle ?

An oracle is a provider of external data to smart contracts, let’s say you want to have a smart contract release some funds or perform some other action when something in the external world happens ( a stock price, a business event, life ). Your first option is to manually signal the contract by calling a method or changing a variable:

// A child is born, so a nurse in the hospital calls a registry contract(pseudo code):
stKenosHospitalBirthRegistryContract.newBaby.call…