chuanqin3 / Udacity-Blockchain-Project-2

Blockchain Data

Blockchain has the potential to change the way that the world approaches data. Develop Blockchain skills by understanding the data model behind Blockchain by developing your own simplified private blockchain.

Getting Started

These instructions will get you a copy of the project up and running on your local machine for development and testing purposes.

Prerequisites

Installing Node and NPM is pretty straightforward using the installer package available from the (Node.js® web site)[https://nodejs.org/en/].

Configuring your project

• Use NPM to initialize your project and create package.json to store project dependencies.

npm init

• Install crypto-js with --save flag to save dependency to our package.json file

npm install crypto-js --save

• Install level with --save flag

npm install level --save

Testing

To test code:

1. Open a command prompt or shell terminal after install node.js.
2. Enter a node session, also known as REPL (Read-Evaluate-Print-Loop).

node
.load simpleChain.js

3. The simpleChain.js will initiate the blockchain for you, and add 10 blocks after Genesis block
4. Validate a block, using Genesis block as an example

chain.validateBlock(0);

5. Feel free to generate another 10 (or any number you like) blocks using a for loop

for (var i = 0; i <= 10; i++) {
  blockchain.addBlock(new Block("test data "+i));
}

6. Validate blockchain

chain.validateChain();

7. Get Block information

chain.getBlock(0).then((c)=>{console.log(c)});