javascript - 格式化 chart.js x 标签

Question

我将 chart.js 与 React 一起使用。我的问题是如何每月仅显示一次月份标签(MMM)？
图表当前有标签:[May 15, May 18, May 21, May 24, ...] 结果我想得到:[May 15, 18, 21, 24, 27, 30, Jun 2, 5, ...] CodeSandbox

折线图:

import React from 'react'
import { Line } from 'react-chartjs-2'
import date from 'date-and-time'

const startDate = new Date(2020, 4, 15)

//===fake data===
const json = '{"responses":[{"rows":[{"values":["1"]},{"values":["0"]},{"values":["0"]},{"values":["0"]},{"values":["0"]},{"values":["0"]},{"values":["0"]},{"values":["0"]},{"values":["0"]},{"values":["0"]},{"values":["0"]},{"values":["0"]},{"values":["0"]},{"values":["0"]},{"values":["0"]},{"values":["0"]},{"values":["0"]},{"values":["0"]},{"values":["0"]},{"values":["0"]},{"values":["0"]},{"values":["0"]},{"values":["0"]},{"values":["0"]},{"values":["0"]},{"values":["0"]},{"values":["0"]},{"values":["0"]},{"values":["0"]},{"values":["0"]},{"values":["0"]},{"values":["0"]},{"values":["0"]},{"values":["0"]},{"values":["0"]},{"values":["0"]},{"values":["0"]},{"values":["0"]},{"values":["0"]},{"values":["0"]},{"values":["0"]},{"values":["0"]},{"values":["0"]},{"values":["0"]},{"values":["0"]},{"values":["0"]},{"values":["0"]},{"values":["0"]},{"values":["1"]},{"values":["6"]},{"values":["7"]},{"values":["5"]},{"values":["8"]},{"values":["9"]},{"values":["2"]},{"values":["1"]},{"values":["1"]},{"values":["1"]},{"values":["6"]},{"values":["3"]},{"values":["0"]},{"values":["20"]},{"values":["9"]},{"values":["3"]},{"values":["2"]},{"values":["1"]},{"values":["13"]},{"values":["3"]},{"values":["13"]},{"values":["13"]},{"values":["7"]},{"values":["12"]},{"values":["0"]}]}]}'
const values = JSON.parse(json).responses[0].rows.map((row, index) => {
  let date = new Date(2020, 4, 20)
  date.setDate(startDate.getDate() + index)
  return {
    y: row.values[0],
    x: date,
  }
})
//===============

const options = {
  legend: {
    display: false,
  },
  hover: {
    mode: 'index',
    intersect: false,
    animationDuration: 0,
  },
  scales: {
    yAxes: [{ position: 'right' }],
    xAxes: [{
      gridLines: { display: false },
      distribution: 'linear',
      type: 'time',
      time: {
        parser: 'MMM D',
        tooltipFormat: 'MMM D',
        unit: 'day',
        unitStepSize: 3,
        displayFormats: {
          day: 'MMM D',
        },
      },
      ticks: {
        min: startDate,
        max: date.format(date.addDays(new Date(), 1), 'MMM D'),
        autoSkip: true
      },
    }],
  },
  tooltips: {
    mode: 'x-axis',
  },
}

const data = {
  datasets: [
    {
      label: 'test',
      fill: false,
      data: values,
      backgroundColor: '#fff',
      borderWidth: 2,
      lineTension: 0,
      borderColor: 'forestgreen',
      hoverBorderWidth: 2,
      pointBorderColor: 'rgba(0, 0, 0, 0)',
      pointBackgroundColor: 'rgba(0, 0, 0, 0)',
      pointHoverBackgroundColor: '#fff',
      pointHoverBorderColor: 'forestgreen',
      showLine: true,
    }
  ],
}

const LineChart = () => <Line data={data} options={options}/>

export default LineChart

Answer 1

解决方案 1 标签过滤器:
根据filtering labels sample您可以设置一个函数来定义应显示的内容:

options: {
    scales: {
        x: {
            display: true,
            ticks: {
                callback: function(dataLabel, index) {
                    // Apply logic to remove name of the month
                    return dataLabel
                }
            }
        },
        y: {
            display: true,
            beginAtZero: false
        }
    }
}

Github source of the example
解决方案2:
您可以事先准备好您的标签数组。过滤所有即将出现的提及并将此数组提供给 chart.js。