javascript - 工具提示自定义不适用于 Google 图表

Question

我正在尝试为 Google Charts 时间线图表创建自定义工具提示，但无法显示自定义字符串。图表仍显示默认工具提示。

  google.charts.load('current', {'packages':['timeline']});
google.charts.setOnLoadCallback(drawChart);

function drawChart() {
  var data = new google.visualization.DataTable();
  data.addColumn('string', 'Team');
  data.addColumn('date', 'Season Start Date');
  data.addColumn('date', 'Season End Date');
  data.addColumn({type: 'string', role: 'tooltip'});

  data.addRows([
    ['Baltimore Ravens',     new Date(2000, 8, 5), new Date(2001, 1, 5), 'my tooltip'],
    ['New England Patriots', new Date(2001, 8, 5), new Date(2002, 1, 5), 'my tooltip'],
  ]);

  var options = {
    height: 450,
    timeline: {
      groupByRowLabel: true
    }
  };

  var chart = new google.visualization.Timeline(document.getElementById('chart_div'));

  chart.draw(data, options);
}

这里是 Google 图表文档:https://developers.google.com/chart/interactive/docs/customizing_tooltip_content

JSFiddle:https://jsfiddle.net/nt12ev9h/

我做错了什么？

Answer 1

正如 WhiteHat 所说，我的专栏出现了故障。

function drawChart() {
  var data = new google.visualization.DataTable();
  data.addColumn('string', 'Team');
  data.addColumn('string', 'Time');
  data.addColumn({type: 'string', role: 'tooltip'});
  data.addColumn('date', 'Season Start Date');
  data.addColumn('date', 'Season End Date');

  data.addRows([
    ['Baltimore Ravens',  '', 'my tooltip',   new Date(2000, 8, 5), new Date(2001, 1, 5)],
    ['New England Patriots', '', 'my tooltip', new Date(2001, 8, 5), new Date(2002, 1, 5)],
  ]);

更新了 JSFiddle:https://jsfiddle.net/nt12ev9h/2/