Unable to connect to geth

Question

I'm totally new to Ethereum, and want to create some deposit address monitoring system using web socket. Which gets newly generated blocks and scan it for transactions made into it. You can find code here: https://github.com/AlanL1/Ethereum-FrontEnd

But geth is not connected with application. I have already installed geth

Am i missing something?

Answer 1

you can use this sample code:

    if(type of web3 !== 'undefined'){
         // Use injected web3 by Metamask/Mist
         window.web3js = new Web3(web3.currentProvider);
     } else {
         // Fallback to local node
         // you can use Infura Node Urls also
         // 'http://127.0.0.1:8545' will be replaced by 
         // 'https://ropsten.infura.io/<API KEy>'
         window.web3js = new Web3(new Web3.providers.HttpProvider('http://127.0.0.1:8545'));
     }

here you can see i have added web3js instance, instead of replacing web3 instance injected by Metamask or Mist.

Update

To consume JSON-RPC API's over WebSockets, use web3.js beta version 1.0.0-beta https://github.com/ethereum/web3.js/tree/1.0

First expose RPC API's over Web Socket Interface

geth --testnet --ws --wsorigins="*"

then instantiate web3 in your page as

web3 = new Web3("ws://127.0.0.1:8546");   

Written a detailed blog on setting up local geth node & communicating with it. http://blog.kherwa.com/2018/05/10/building-a-dapp-series-part1-set-up-and-communicate-with-an-ethereum-node/