Picking up echo_req responses

Middleend

Hi there,

Another noob question. would like to get Tick_history_update with the subscribe function. msg1 arrives as msg_type : 'candles' with history and I can successfully map this to a new HTML table no problem. I want to merge the original JSON and ohlc JSON's. The table creates no problem but defining the data for 'ohlc' is the difficulty. I keep getting 'undefined' errors. I have been going round in circles for days. I am sure it will be the simplest oversight on my behalf, but if someone could kindly point out the error of my ways it would be much appreciated, please. Code I am using so far is below:

    ws.onopen = function(evt) {
    ws.send(JSON.stringify({ "ticks_history": "frxGBPUSD","end": "latest","count": 86400,"style":"candles","granularity": 14400,"subscribe":1})); }
    ws.onmessage = function(msg) {
        var data = JSON.parse(msg.data); console.log('ticks_history update: %o', data);     
         for (var i = 0; i < data["msg_type"].length; i ++){ 
            var arr1 = data.candles.map(function(candles){ return { 
                    day : moment(candles.epoch*1000).format('DD/MM/YYYY'), 
                    time : moment(candles.epoch*1000).format('HH:MM:SS'), 
                    open : candles.open, 
                    high : candles.high, 
                    low : candles.low, 
                    close : candles.close}; });}
                    console.log('can_Array: %o', arr1);
         if( typeof data.candles !== 'undefined' ){
            var echo = ["ohlc"];
            for (var i = 0; i < echo.length; i ++){ 
            var arr2 = echo.map(function(echo){ return { 
                    day : moment(echo.epoch*1000).format('DD/MM/YYYY'), 
                    time : moment(echo.open_time*1000).format('HH:MM:SS'), 
                    open : echo.open, 
                    high : echo.high, 
                    low : echo.low, 
                    close : echo.close};});}}
         console.log('tic_Array: %o', arr2);
        var liv = arr1.concat(arr2);

Many thanks.

Raunak

@Middleend why not do something like this

ws.onopen = function(evt) {
    ws.send(JSON.stringify({ 
        "ticks_history": "frxGBPUSD","end": "latest","count": 86400,"style":"candles","granularity": 14400,"subscribe":1 })
    ); 
}

ws.onmessage = function(msg) {
    var data = JSON.parse(msg.data); 

    // categorised based on msg_type rather than data
    if (data["msg_type"] === "candles") {
        var arr1 = data["candles"].map(function(candles) {
            return {
                day: moment(candles.epoch * 1000).format('DD/MM/YYYY'),
                time: moment(candles.epoch * 1000).format('HH:MM:SS'),
                open: candles.open,
                high: candles.high,
                low: candles.low,
                close: candles.close
            };
        });
    } else if (data["msg_type"] === "ohlc") {
        var ohlc = data["ohlc"];
        // play with it, use it the way you want
    }
}

Middleend

Thanks @Raunak unfortunately this has no helped, but I have learned a lot from it thank you. The code works for the map funcrion to create the arrays, I can define elements of the very first JSON message and produce the table, can create the second array but am unable to define the components. The tick_history_update continues but ignores the typeof catch and get the errors. I have checked the JSON in the API playground and it is "ohlc", {"ohlc" [...... please see below screen shot.

of the console log. if use if and if else the results are the same...many thanks once again.

ws.send(JSON.stringify({
    "ticks_history": "frxGBPUSD",
    "end": "latest",
    "count": 86400,
    "style": "candles",
    "granularity": 14400,
    "subscribe": 1
}));
}
ws.onmessage = function(msg) {
        var data = JSON.parse(msg.data);
        console.log('ticks_history update: %o', data);
        for (var i = 0; i < data["msg_type"].length; i++) {
            var arr1 = data["candles"].map(function(candles) {
                return {
                    day: moment(candles.epoch * 1000).format('DD/MM/YYYY'),
                    time: moment(candles.epoch * 1000).format('HH:MM:SS'),
                    open: candles.open,
                    high: candles.high,
                    low: candles.low,
                    close: candles.close
                };
            });
        }
        console.log('can_Array: %o', arr1);
        if (data.candles !== 'undefined') {
            var echo = ["ohlc"];
            for (var i = 0; i < echo.length; i++) {
                var arr2 = echo.map(function(echo) {
                    return {
                        day: moment(echo.epoch * 1000).format('DD/MM/YYYY'),
                        time: moment(echo.open_time * 1000).format('HH:MM:SS'),
                        open: echo.open,
                        high: echo.high,
                        low: echo.low,
                        close: echo.close
                    };
                });
            }
        }
        console.log('tic_Array: %o', arr2);
        var liv = arr1.concat(arr2);

Raunak

The problem with your code is that you are checking msg_type length for (var i = 0; i < data["msg_type"].length; i++) { rather than type of it.

When you request ticks_history with subscribe first it returns candles from time to current time (if no end_time) with msg_type: candles then it will start streaming ohlc from there on hence change of msg_type

Middleend

Thanks Raunak I think Inhave cracked it now needed to set up a function to parse ohlc. Many thanks for your support