如何获得stackedBar ChartJs中的总值之和

Question

我正在尝试获取stackedBar的所有值的总和,并在工具提示中包含此总数.

注意:我的数据集不是静态的,这是一个例子

var barChartData = {
        labels: ["January", "February", "March", "April", "May", "June", "July"],
        datasets: [{
            label: 'Corporation 1',
            backgroundColor: "rgba(220,220,220,0.5)",
            data: [50, 40, 23, 45, 67, 78, 23]
        }, {
            label: 'Corporation 2',
            backgroundColor: "rgba(151,187,205,0.5)",
            data: [50, 40, 78, 23, 23, 45, 67]
        }, {
            label: 'Corporation 3',
            backgroundColor: "rgba(151,187,205,0.5)",
            data: [50, 67, 78, 23, 40, 23, 55]
        }]

    };

    window.onload = function() {
        var ctx = document.getElementById("canvas").getContext("2d");
        window.myBar = new Chart(ctx, {
            type: 'bar',
            data: barChartData,
            options: {
                title:{
                    display:true,
                    text:"Chart.js Bar Chart - Stacked"
                },
                tooltips: {
                    mode: 'label',
                    callbacks: {
                       label: function(tooltipItem, data) {
                       var corporation = data.datasets[tooltipItem.datasetIndex].label;
                       var valor = data.datasets[tooltipItem.datasetIndex].data[tooltipItem.index];
                       var total = eval(data.datasets[tooltipItem.datasetIndex].data.join("+"));
                       return total+"--"+ corporation +": $" + valor.toFixed(2).replace(/(\d)(?=(\d{3})+\.)/g, '$1,');
                  }
                    }
                },
                responsive: true,
                scales: {
                    xAxes: [{
                        stacked: true,
                    }],
                    yAxes: [{
                        stacked: true
                    }]
                }
            }
        });
    };

现在total是每个数据集的总和,我需要每个stackedBar的总和.

例

标签A:价值A.

标签B:值B.

标签C:值C

总计:值A +值B +值C.

有可能获得总价值吗？

谢谢,Idalia.

Answer 1

我修改了tektiv的答案,只显示活动集的Total,并将其移动到工具提示页脚.

tooltips: {
        mode: 'label',
        callbacks: {
            afterTitle: function() {
                window.total = 0;
            },
            label: function(tooltipItem, data) {
                var corporation = data.datasets[tooltipItem.datasetIndex].label;
                var valor = data.datasets[tooltipItem.datasetIndex].data[tooltipItem.index];
                window.total += valor;
                return corporation + ": " + valor.toString().replace(/\B(?=(\d{3})+(?!\d))/g, " ");             
            },
            footer: function() {
                return "TOTAL: " + window.total.toString().replace(/\B(?=(\d{3})+(?!\d))/g, " ");
            }
        }
    }

Answer 2

首先,您应该知道,如果callback在工具提示中返回数组而不是单个字符串,它将显示数组中的所有字符串,就好像它是不同的数据集一样(有关详细信息,请参阅此答案).

所以我编辑了一下你的回调以下内容:

callbacks: {
    label: function(tooltipItem, data) {
        var corporation = data.datasets[tooltipItem.datasetIndex].label;
        var valor = data.datasets[tooltipItem.datasetIndex].data[tooltipItem.index];

        // Loop through all datasets to get the actual total of the index
        var total = 0;
        for (var i = 0; i < data.datasets.length; i++)
            total += data.datasets[i].data[tooltipItem.index];

        // If it is not the last dataset, you display it as you usually do
        if (tooltipItem.datasetIndex != data.datasets.length - 1) {
            return corporation + " : $" + valor.toFixed(2).replace(/(\d)(?=(\d{3})+\.)/g, '$1,');
        } else { // .. else, you display the dataset and the total, using an array
            return [corporation + " : $" + valor.toFixed(2).replace(/(\d)(?=(\d{3})+\.)/g, '$1,'), "Total : $" + total];
        }
    }
}

你可以在这个jsFiddle中看到完整的代码,结果如下:

Answer 3

加斯帕答案的简短版本：

tooltips: {
  callbacks: {
    footer: (tooltipItems, data) => {
      let total = tooltipItems.reduce((a, e) => a + parseInt(e.yLabel), 0);
      return 'Total: ' + total;
    }
  }
}

示例：https : //jsfiddle.net/g3ba60zc/2/

Answer 4

在其他答案中，您不需要替换最后一个数据集

tooltips: {
    callbacks: {
        title: function(tooltipItems, data) {
            return _this.chart.data.labels[tooltipItems[0].index];
        },
        footer: function(tooltipItems, data) {
            let total = 0;
            for (let i = 0; i < tooltipItems.length; i++) {
                total += parseInt(tooltipItems[i].yLabel, 10);
            }
            return 'Total: ' + total;
        }
    }
}

附言：这是打字稿郎。