This boilerplate uses Web3.js and MetaMask to connect to blockchain in HTML5.

It also shows an example of:

• using a web3 method
• using call() on a contract's method that doesn't require gas
• using send() on a contract's method that requires gas
• subscribing to an Event

1. You should have a smart contract deployed to the blockchain first. If you don't, you can deploy ./SampleContract.sol with remix.ethereum.org. Take a note of the deployed contract's address.
2. Set the variables contractAddress and contractAbi in ./index.js. The contractAbi takes a path to a JSON file. You will find the ABI for ./SampleContract.sol in ./sampleAbi.json.
3. Make sure you have the MetaMask Chrome plugin activated and you are logged in to your account.
4. Run ./index.html in localhost (to start a localhost, you can use the Live Server extension for VS Code for example).