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.
These instructions will get you a copy of the project up and running on your local machine for development and testing purposes.
Installing Node and NPM is pretty straightforward using the installer package available from the (Node.js® web site)[https://nodejs.org/en/].
- 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
- Add levelSanbox.js and simpleChain.js to Project
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
3: Copy and paste your code [levelSanbox.js and simpleChain.js] into your node session
4: Instantiate blockchain with blockchain variable. Genesis Block will be created, as we are doing for the first time
let blockchain = new Blockchain();
5: Generate 10 blocks using a for loop
for (var i = 0; i <= 10; i++) {
blockchain.addBlock(new Block("test data "+i));
}
Note: For testing, I have added 4 Blocks.
blockchain.addBlock(new Block("First Custom Block"));
6: Check the Block height
blockchain.getBlockHeight();
7: Get Details of particular Block
blockchain.getBlock("2")
8: Validate Block
blockchain.validateBlock("2")
9: Validate BlockConnection
blockchain.validateBlockConnection("2")
10: Validate Blockchain
blockchain.validateChain();
11: Print BlockChain
blockchain.printBlockChain();
12: Induce errors by changing block data [This is created intentionaly to check this scenario ]
addLevelDBData("2", new Block("It's an Induced Error"));
8: Validate blockchain. The chain should now fail .
blockchain.validateChain();
