更改Google差异图表中的工具提示名称（当前和先前）

Question

我想为调查创建一个Google差异图。这将显示用户总数和调查给定的用户。我的JavaScript代码是：-

google.charts.load('current', {packages: ['corechart']});
google.charts.setOnLoadCallback(drawChart);
function drawChart() {
    var overallData = [];
    var givenData = [];
    overallData.push(['Department', 'Total Users']);
    givenData.push(['Department', 'Given feedback']);
    for (var i in data) {
        overallData.push([data[i].department_name, data[i].emp_count]);
        givenData.push([data[i].department_name, data[i].upward_done]);
    }
    var oldData = google.visualization.arrayToDataTable(overallData);
    var newData = google.visualization.arrayToDataTable(givenData);
    var colChartDiff = new google.visualization.ColumnChart(document.getElementById('feedback_dept_chart'));
    var options = {
        fontName: 'Calibri',
        legend: 'none',
        height: 200,
        width: 960,
        vAxis: {title: 'No of employee'},
        tooltip: {isHtml: false}
    };
    var diffData = colChartDiff.computeDiff(oldData, newData);
    colChartDiff.draw(diffData, options);

数据是：-

[{"department_name":"Design","emp_count":1,"upward_done":1},
 {"department_name":"Management","emp_count":1,"upward_done":0},
 {"department_name":"Technology","emp_count":3,"upward_done":2}]

差异图的问题在于它显示了名为“当前”和“上一个”的工具提示。我想通过“总用户数”和“调查给定用户数”来更改它。

任何帮助将不胜感激。谢谢

Answer 1

将以下工具提示代码添加到选项中

    diff: { 
            oldData: { opacity: 1, color: 'yellow',
                 tooltip:{
                    prefix:'Label 1'
                    } 
                  }, 
            newData: { opacity: 1, widthFactor: 1,
                 tooltip:{
                    prefix:'Label 2'
                    }
                 }
          }