Blockchain Live Transactions

livetransactions.js

function BlockchainRealtime(callback){

    /**
     * Opens a stream which subscribes to receive new unconfirmed transactions
     * on the blockchain
     * @param {function} callback which accepts a object of the form {input: array: output: array}
     * @returns {function} return value of this function is a function, which will stop the stream if called.
     */

    const sock = new WebSocket('wss://ws.blockchain.info/inv');
    
    sock.onmessage = function(msg){
        let data = JSON.parse(msg.data);
        let input = data.x.inputs[0].prev_out;
        let output = data.x.out[0];
        callback({"input": input, "output": output})
        
    }
    sock.onopen = function(ev){
        sock.send(JSON.stringify({"op":"unconfirmed_sub"}))
    }
    
    return function(){
        sock.send(JSON.stringify({"op": "unconfirmed_unsub"}));
    }
}