setLoadMoreDataCallback doesn't fire up.

[mj91-prog]

it seems I'm unable to load data as I scroll through the end of the chart, I thought of using the setLoadMoreDataCallback function for the task. this is my code:

` onMount(async () => {
chart = init("chart-container");
chart.setPrecision({ price: 5 });

await LoadChartConfiguration(chart);
await LoadDataConfiguration();
await LoadAssetData(chart);

chart.setLoadMoreDataCallback(({ type, data, callback }) => {
  console.log("data:", data); // it doesn't even print this
  if (type === "forward") {
    console.log(type);
    const date = formatDate(data.timestamp);
    fetch(
      `http://localhost:4000/LoadAssetSlice/${current_asset}/forward/${date}`
    )
      .then((res) => res.json())
      .then((dataList) => {
        const _data = formatOHLCData(dataList["data"]);
        let bars = CreateCustomBars(current_timeframe, _data);
        callback(bars, dataList["data"].length == 10000);
      });
  } else if (type === "backward") {
    console.log(type);
    const date = formatDate(data.timestamp);
    fetch(
      `http://localhost:4000/LoadAssetSlice/${current_asset}/backward/${date}`
    )
      .then((res) => res.json())
      .then((dataList) => {
        const _data = formatOHLCData(dataList["data"]);
        let bars = CreateCustomBars(current_timeframe, _data);
        callback(bars, dataList["data"].length == 10000);
      });
  }
});

});`

the problems seems that It doesn't even try to run the callback function despite reaching the far end of the chart in both directions. Any suggestions ? (ps:I'm using svelte as frontend )

[mj91-prog]

It turned out that you have to pass a true boolean value at the applyNewData function as second parameter, when you insert data for the first time, in order to signal the existence of more data to be added and the same goes for the second parameter of callback function.
To be fair this in the API is not specified.