A voting application demo for codemash

• Get online (CodeMash)

• VM is available here

• Check if npm is installed using this command on the Ubuntu terminal npm -v

• You will get a version number starting with 5, you are good to go the next step.

• Clone this git repo like this git clone https://github.com/abhi12ravi/blockchain-vote.git

• cd into the repo

• Run this command to install web3 and ganache-cli sudo npm install ganache-cli web3@0.20.1

• Install the solidity compiler npm install solc Note: testrpc is deprecated and now we have ganache-cli

• Start the test blockchain network like this: node_modules/.bin/testrpc. If all is well, this returns a list of 10 eth accounts and starts the blockchain network.

If you get an error message npm update check failed, run this on terminal -

• sudo chown -R $USER:$(id -gn $USER) /home/<username>/.config
• sudo npm install -g npm

$node_modules/.bin/ganache-cli

> Web3 = require('web3')

> web3 = new Web3(new Web3.providers.HttpProvider("http://localhost:8545"));

> web3.eth.accounts
> code = fs.readFileSync('Voting.sol').toString()
>solc = require('solc')
> compiledCode = solc.compile(code)

> abiDefinition = JSON.parse(compiledCode.contracts[':Voting'].interface)
> VotingContract = web3.eth.contract(abiDefinition)
> byteCode = compiledCode.contracts[':Voting'].bytecode

> deployedContract = VotingContract.new(['Rama','Nick','Jose'],{data: byteCode, from: web3.eth.accounts[0], gas: 4700000})
> deployedContract.address
> contractInstance = VotingContract.at(deployedContract.address)

>contractInstance.totalVotesFor.call('Rama')
{ [String: '0'] s: 1, e: 0, c: [ 0 ] }

>contractInstance.voteForCandidate('Rama', {from: web3.eth.accounts[0]})

>contractInstance.totalVotesFor.call('Rama').toLocaleString()
'3'

Save the contractInstance.address for next exercise.

• Clone this repo
• Open index.js and change the contractInstance.address to your own address
• Open index.html on any browser
• Increment votes and play around.

Part 2: https://medium.com/@mvmurthy/full-stack-hello-world-voting-ethereum-dapp-tutorial-part-2-30b3d335aa1f