Javascript / Blockchain.info Websocket API Address Subscription

Question

I am new to bitcoin, Blockchain.info API and javascript, however, i am trying to implement a code that tracks Live Payments notification on a particular bitcoin address. The idea here is... after the user scans the QR image <img src="http://chart.googleapis.com/chart?chs=200x200&cht=qr&chl=12fMma2J15qre9bZPsX3AerdgWd9Poe9ee">, and makes payment to the BTC address, 12fMma2J15qre9bZPsX3AerdgWd9Poe9ee, the Div with ID #websocket will instantly display Live (without refreshing the webpage), the amount of Bitcoins Transaferred to the address, thus switching the initial content of the div from monitoring... to the amount transferred Recieved: 0.003 BTC.

I have written a piece of code ... but i'm not sure what i'm missing. Please Help. Thank you.

The code:

        <div class="row">
            <div class="col-md-4 "> 
                <img src="http://chart.googleapis.com/chart?chs=200x200&cht=qr&chl=12fMma2J15qre9bZPsX3AerdgWd9Poe9ee"> 
                <div id="websocket">
                    Monitoring Transactions ...
                </div>

                <script>
                var btcs = new WebSocket("12fMma2J15qre9bZPsX3AerdgWd9Poe9ee");
                btcs.onopen = function() {
                    btcs.send(JSON.stringify({"op":"addr_sub", "addr":"12fMma2J15qre9bZPsX3AerdgWd9Poe9ee"}));
                };

                btcs.onmessage = function (onmsg) {
                    var response = JSON.parse(onmsg.data);
                    var getOutputs = response.x.out;
                    var countOuts = getOutputs.length;

                    for (i=0; i < countOuts; i++){
                        var outAdd = response.x.out[i].addr;
                        var address = "12fMma2J15qre9bZPsX3AerdgWd9Poe9ee";
                        if (outAdd == address){
                            var amount =response.x.out[i].value;
                            var calAmount = Amount / 100000000;
                            document.getElementById("websocket").innerHTML = "Recieved" + calAmount + "BTC";
                        }
                    }
                };
                </script>

            </div>
            <div class="col-md-8">
                <!-- more html stuff goes here -->
            </div>
        </div>

score 2 · Answer 1 · answered Dec 28 '17 at 02:30

2

I don't see anywhere in the code a connection being made to blockchain's api, so I'm guessing this

var btcs = new WebSocket("12fMma2J15qre9bZPsX3AerdgWd9Poe9ee");

should use the api's address instead of the target bitcoin wallet address.

answered Dec 28 '17 at 02:30

Daniel Sousa

81
8

score 1 · Answer 2 · answered Dec 18 '17 at 18:39

1

Probably you need to put wss://ws.blockchain.info/inv while starting a new socket at the place of address.

answered Dec 18 '17 at 18:39

A.K.

326
3
18

above WebSocket api will not work for TestNet address?? – shankar May 29 '18 at 11:53

score 1 · Answer 3 · edited Mar 08 '19 at 05:16

    <div class="row">
        <div class="col-md-4 "> 
            <img src="http://chart.googleapis.com/chart?chs=200x200&cht=qr&chl=12fMma2J15qre9bZPsX3AerdgWd9Poe9ee"> 
            <div id="websocket">
                Monitoring Transactions ...
            </div>

            <script>
            var btcs = new WebSocket("wss://ws.blockchain.info/inv");
            btcs.onopen = function() {
                btcs.send(JSON.stringify({"op":"addr_sub", "addr":"12fMma2J15qre9bZPsX3AerdgWd9Poe9ee"}));
            };

            btcs.onmessage = function (onmsg) {
                var response = JSON.parse(onmsg.data);
                var getOutputs = response.x.out;
                var countOuts = getOutputs.length;

                for (i=0; i < countOuts; i++){
                    var outAdd = response.x.out[i].addr;
                    var address = "12fMma2J15qre9bZPsX3AerdgWd9Poe9ee";
                    if (outAdd == address){
                        var amount =response.x.out[i].value;
                        var calAmount = Amount / 100000000;
                        document.getElementById("websocket").innerHTML = "Recieved" + calAmount + "BTC";
                    }
                }
            };
            </script>

        </div>
        <div class="col-md-8">
            <!-- more html stuff goes here -->
        </div>
    </div>

Javascript / Blockchain.info Websocket API Address Subscription

3 Answers3