在气泡图上的某个点下方对齐数据标签 (Chart.JS)

Question

我正在尝试将与数据集相关的标签放置在气泡图上某个点的下方，并将值显示在该点的顶部。

我尝试返回两个不同的值，但它只允许我返回一个。

因此，我在同一个字符串中返回了两个值。

是否可以返回标签并将其放置在数据集的值下方并将值放在数据集的点上方？

如果不可能，是否有可能在我添加到字符串的换行符后以某种方式使文本与中心对齐？

Here is what I have so far

This is what I am trying to achieve, but with the value above the bubble

到目前为止，这是我的代码：

var ctx = document.getElementById('myChart').getContext('2d');

var myChart = new Chart(ctx, {

    type: 'bubble',

    data: {
        datasets: [
            {
                label: 'Top',
                data: [
                    {x: 110, y: 0, r: 12, name: "Performance"}
                ],
                backgroundColor: "rgba(255,255,255,1)",
                borderColor: "rgba(91,182,209,1)",
                borderWidth: 2,
                hoverBackgroundColor: "rgba(255,255,255,1)",
                hoverBorderWidth : 2
            },
            {
                label: 'Average',
                data: [
                    {x: 75, y: 0, r: 12, name: "Performance"}
                ],
                backgroundColor: "rgba(255,255,255,1)",
                borderColor: "rgba(91,182,209,1)",
                borderWidth: 2,
                hoverBackgroundColor: "rgba(255,255,255,1)",
                hoverBorderWidth : 2
            },
            {
                label: 'You 2017',
                data: [
                    {x: 55, y: 0, r: 15, name: "Performance"}
                ],
                backgroundColor: "rgba(255,255,255,1)",
                borderColor: "rgba(91,182,209,1)",
                borderWidth: 2,
                hoverBackgroundColor : "rgba(255,255,255,1)",
                hoverBorderWidth : 2
            },
            {
                label: 'You 2018',
                data: [
                    {x: 90, y: 0, r: 15, name: "Performance"} // The labe needs to be
                ],
                backgroundColor: "rgba(255,255,255,1)",
                borderColor: "rgba(91,182,209,1)",
                borderWidth: 2,
                hoverBackgroundColor : "rgba(255,255,255,1)",
                hoverBorderWidth : 2
            }
        ]
    },
    options: {
        legend: {
            display: false
        },
        plugins: {
            datalabels: {
                anchor: function (context) {
                    var value = context.dataset.data[context.dataIndex];
                    return value.x < 1000 ? 'end' : 'center';
                },
                align: function (context) {
                    var value = context.dataset.data[context.dataIndex];
                    return value.x < 1000 ? 'end' : 'center';
                },
                color: function (context) {
                    var value = context.dataset.data[context.dataIndex];
                    return value.x < 1000 ? context.dataset.borderColor : 'white';
                },
                font: {
                    weight: 'bold'
                },
                formatter: function (value, context) {
                    ctx.textAlign = "center";
                    return context.dataset.label + "\n" + Math.round(value.x);
                },
                offset: 2,
                padding: 0
            }
        },
        maintainAspectRatio: false,
        scales: {
            yAxes: [{
                id: 'first-y-axis',
                type: 'linear',
                ticks: {
                    min: 0,
                    max: 1,
                    stepSize: 1,
                    display: false
                },
                gridLines: {
                    display: false,
                    drawBorder: false
                }
            }],
            xAxes: [
                {
                    id: 'first-x-axis',
                    ticks: {
                        min: 50, // Controls where axis starts
                        max: 120, // Controls where axis finishes
                        stepSize: 70 // Control the gap between the first x-axis value and the last x-axis value
                    },
                    gridLines: {
                        display: false,
                        lineWidth: 3 // Width of bottom line
                    }
                }
            ]

        }
    }

});

任何帮助或建议将不胜感激^_^

Answer 1

我通过在图表参数中应用“textAlign”并将其设置为中心来解决这个问题。

您可以在下面的代码中看到这一点：

plugins: {
    datalabels: {
        anchor: function (context) {
            var value = context.dataset.data[context.dataIndex];
            return value.x < 1000 ? 'end' : 'center';
        },
        align: function (context) {
            var value = context.dataset.data[context.dataIndex];
            return value.x < 1000 ? 'end' : 'center';
        },
        color: function (context) {
            var value = context.dataset.data[context.dataIndex];
            return value.x < 1000 ? context.dataset.borderColor : 'white';
        },
        textAlign: 'center',
        font: {
            weight: 'bold',
            alignment: 'right' // Is this the place to be doing this?
        },
        formatter: function (value, context) {
            return context.dataset.label + '\n' + Math.round(value.x);
        },
        offset: 2,
        padding: 0
    }
},

希望对你有所帮助^^