javascript - 如何使用 JSON 数据为 Google Charts 实现样式或属性？

Question

使用 JSON 格式数据时，将样式/属性应用于 Google 可视化图表的各个点的正确方法是什么？具体来说，我需要根据数据更改图表上各个点的颜色。例如 - 使用下面的 JSFiddle，您将如何将第一个点更改为另一种颜色？我尝试了各种使用“p”(属性)字段的选项，但没有成功。有人知道怎么做吗？

https://jsfiddle.net/burtonrhodes/fpd08jrt/14/

Json 数据

{
  "cols": [
    {
      "id": "Week",
      "label": "Week",
      "type": "string",
      "pattern": null,
      "p": null
    },
    {
      "id": "Showings",
      "label": "Showings",
      "type": "number",
      "pattern": null,
      "p": null
    }
  ],
  "rows": [
    {
      "c": [
        {
          "v": "1",
          "f": null,
          "p": null
        },
        {
          "v": 2,
          "f": null,
          "p": {"point" : "fill-color: #FF7A06;"}
        }
      ]
    },
    {
      "c": [
        {
          "v": "2",
          "f": null,
          "p": null
        },
        {
          "v": 1,
          "f": null,
          "p": null
        }
      ]
    }
  ]
}

Answer 1

在使用json时，这与其他答案的概念相同，
在样式的系列列之后添加一列，
如下……

{
  "cols": [
    {
      "id": "Week",
      "label": "Week",
      "type": "string",
      "pattern": null,
      "p": null
    },
    {
      "id": "Showings",
      "label": "Showings",
      "type": "number",
      "pattern": null,
      "p": null
    },
    {
      "id": "Sytle",
      "role": "style",
      "type": "string",
      "pattern": null,
      "p": null
    }
  ],
  "rows": [
    {
      "c": [
        {
          "v": "1",
          "f": null,
          "p": null
        },
        {
          "v": 2,
          "f": null,
          "p": null
        },
        {
          "v": "point {fill-color: #ff7a06;}",
          "f": null,
          "p": null
        }
      ]
    },
    {
      "c": [
        {
          "v": "2",
          "f": null,
          "p": null
        },
        {
          "v": 1,
          "f": null,
          "p": null
        },
        {
          "v": null,
          "f": null,
          "p": null
        }
      ]
    }
  ]
}

关键是要有一个属性 --> "role": "style"
样式应该是行的值。

style role reference

请参阅以下工作片段...

google.charts.load('current', {
  packages: ['corechart']
}).then(function () {
  var data = new google.visualization.DataTable({
    "cols": [
      {
        "id": "Week",
        "label": "Week",
        "type": "string",
        "pattern": null,
        "p": null
      },
      {
        "id": "Showings",
        "label": "Showings",
        "type": "number",
        "pattern": null,
        "p": null
      },
      {
        "id": "Sytle",
        "role": "style",
        "type": "string",
        "pattern": null,
        "p": null
      }
    ],
    "rows": [
      {
        "c": [
          {
            "v": "1",
            "f": null,
            "p": null
          },
          {
            "v": 2,
            "f": null,
            "p": null
          },
          {
            "v": "point {fill-color: #ff7a06;}",
            "f": null,
            "p": null
          }
        ]
      },
      {
        "c": [
          {
            "v": "2",
            "f": null,
            "p": null
          },
          {
            "v": 1,
            "f": null,
            "p": null
          },
          {
            "v": null,
            "f": null,
            "p": null
          }
        ]
      }
    ]
  });

  let chart = new google.visualization.LineChart(document.getElementById('chart'));
  chart.draw(data, {
    title: "Showings by Week",
    fontName: "Arial",
    fontSize: 14,
    titleTextStyle: {
      color: "#2B557D"
    },
    pointSize: 6,
    colors: ['#C6D9FD'],
    lineWidth: 1,
    curveType: "line",
    vAxis: {
      minValue:0,
      viewWindow: {
        min: 0
      },
      maxValue: 3
    },
    hAxis: {
      maxAlternation: 1,
      //title: 'Week'
    },
    legend:  {
      position: 'none'
    },
    tooltip: {
      isHtml: true
    },
    animation:{
      duration: 1500,
      easing: 'out',
      startup: true
    }
  });
});

<script src="https://www.gstatic.com/charts/loader.js"></script>
<div id="chart"></div>