Custom Data Tip With D3 V4

<!DOCTYPE html>
<meta charset="utf-8">

<head>
    <title>Chandrakant Bharatkumar Thakkar</title>
    <link rel="stylesheet" href="./styles.css">
</head>

</div>
    <a href="https://stackoverflow.com/users/7430694/chandrakant-thakkar" style="position: absolute;top: 87%;left: 77%;" target="_blank">
        <img src="https://stackoverflow.com/users/flair/7430694.png" width="208" height="58" alt="profile for Chandrakant Thakkar at Stack Overflow, Q&amp;A for professional and enthusiast programmers" title="profile for Chandrakant Thakkar at Stack Overflow, Q&amp;A for professional and enthusiast programmers">
        </a>
    <script src="./jquery-latest.min.js"></script>
    <script src="./d3.v4.min.js"></script>
    <script src="./constant.js"></script>
    <script>
        var svg = d3.select("svg"),
            width = 800,
            height = 440;

const svgRef = "svg";
        const mainDivRef = ".cumulative-trend";
        const margin = {
            top: 90,
            right: 20,
            left: 50,
            bottom: 50
        };

const ticksSize = 6;

const minMaxValue = d3.extent(preparedChartData.map(data => data.value + data.pastValue));
        const { minValue, maxValue } = calculateMinMaxValue(minMaxValue[0], minMaxValue[1], false, ticksSize);

const minMaxValues = { minValue: Math.round(minValue), maxValue: Math.round(maxValue) };

let binSize = (minMaxValues.maxValue - minMaxValues.minValue) / (ticksSize - 1);
        binSize = Math.round(binSize);
        const tickValues = [];
        let currentValue = minMaxValues.minValue;
        while (currentValue <= minMaxValues.maxValue) {
            tickValues.push(currentValue);
            currentValue = currentValue + binSize;
        }

const dataTips = [...preparedChartData].reverse().filter((d, index) => {
            d.index = index;
            return d.dataTip != null;
        });

const updatedMargin = { ...margin };
        updatedMargin.top = (dataTips.length > 0 && updatedMargin.top < 50) ? 50 : updatedMargin.top;

const yScale = d3.scaleLinear().domain([0, minMaxValues.maxValue])
            .range([(height) - (updatedMargin.bottom + updatedMargin.top), 0]);

var yAxis = d3.axisLeft(yScale).ticks(ticksSize).tickFormat(d => d);

d3.select("svg")
            .append("g")
            .attr("class", "y-axis")
            .attr("transform", "translate(" + updatedMargin.left + "," + updatedMargin.top + ")").call(yAxis);

const ticksCalculationData = getTicksCalculation(preparedChartData[0].date, preparedChartData[preparedChartData.length - 1].date, "day", "0");
        const distinctTicks = ticksCalculationData.distinctTicks.map(d => d.data);
        const xScale = d3.scaleBand()
            .domain(distinctTicks)
            .range([0, width - (updatedMargin.left + updatedMargin.right)]);
        const groupKey = ["value", "pastValue"];
        const layersActual = d3
            .stack()
            .keys(groupKey)
            .offset(d3.stackOffsetDiverging)(preparedChartData);

const xAxisG = d3.select("svg")
            .append("g")
            .attr("transform", "translate(" + updatedMargin.left + "," + (height - (updatedMargin.top - 40)) + ")")

xAxisG.append("g")
            .attr("class", "range-slider-axis");
        CustomXAxis(xScale, width - (updatedMargin.left + updatedMargin.right), ticksCalculationData.distinctTicks, height - (updatedMargin.top + updatedMargin.bottom), preparedChartData);
        let tooltipData = "";
        let topLeftPositionOfTooltip = { topPosition: 100, leftPosition: 100 };
        const onMouseEnterOnBar = (d) => {
            let data = d3.event.target.getBBox();
            data = { x: data.x, y: data.y, width: data.width, height: data.height, ...d };

tooltipData = (
                '<div className="tooltip-table">\
                        <div className="tooltip-table-row">\
                            <span className="header">Current Value:</span>\
                            <span>'+ data.data.value + '</span>\
                        </div>\
                        <div className="tooltip-table-row">\
                            <span className="header">Past Value:</span>\
                            <span>'+ data.data.pastValue + '</span>\
                        </div>\
                    </div>'
            );

topLeftPositionOfTooltip = {
                topPosition:
                data.topY + updatedMargin.top,
                leftPosition: data.x + xScale.bandwidth() / 2 + updatedMargin.left
            };
            callShowTooltip(topLeftPositionOfTooltip.topPosition, topLeftPositionOfTooltip.leftPosition, tooltipData, mainDivRef);

}

const onMouseOutOnBar = () => {
            callHideTooltip(mainDivRef);
        }

const stackBarG = d3.select("svg")
            .append("g")
            .attr("class", "stack-bar")
            .attr("transform", "translate(" + updatedMargin.left + "," + updatedMargin.top + ")").call(yAxis);
        layersActual.length > 0 &&
            layersActual[0].forEach((dataPoint, index) => {
                const pastValue = [0, layersActual[1][index]["1"] - layersActual[1][index]["0"]];
                const currentValue = [pastValue[1], pastValue[1] + dataPoint["1"] - dataPoint["0"]];

stackBarG.append("g")
                    .append("rect")
                    .datum({ topY: yScale(currentValue[1]), data: dataPoint.data })
                    .classed('past-value', true)
                    .attr("x", xScale(ticksCalculationData.distinctTicks[index].data) + 1.5)
                    .attr("y", yScale(pastValue[1]))
                    .style("height", yScale(pastValue[0]) - yScale(pastValue[1]))
                    .style("width", xScale.bandwidth() - 1.5)
                    .style("fill", "#ccc")
                    .style("stroke", "transparent")
                    .on("mouseover", onMouseEnterOnBar)
                    .on("mouseout", onMouseOutOnBar);

stackBarG.append("g")
                    .append("rect")
                    .datum({ topY: yScale(currentValue[1]), data: dataPoint.data })
                    .classed('actual-value', true)
                    .attr("x", xScale(ticksCalculationData.distinctTicks[index].data) + 1.5)
                    .attr("y", yScale(currentValue[1]))
                    .style("height", yScale(currentValue[0]) - yScale(currentValue[1]))
                    .style("width", xScale.bandwidth() - 1.5)
                    .style("fill", "#ccc")
                    .style("stroke", "transparent")
                    .on("mouseover", onMouseEnterOnBar)
                    .on("mouseout", onMouseOutOnBar);

})

setDrawDataTips(dataTips, xScale, yScale, ticksCalculationData.distinctTicks, svgRef, updatedMargin, preparedChartData, mainDivRef);
    </script>