function getRandomNumber(min, max) {
  return Math.floor(Math.random() * (max - min + 1) + min);
};

function generateData(iterations = 100, defaultValues = [], namePrefix = {}, maxJump = 100) {
  const arr = [];
  for (let i = 0; i  {
      if (i === 0 && typeof v.value === 'number') {
        return v;
      }
      return {
        ...v,
        value: i === 0 ? this.getRandomNumber(1, 1000) : arr[i - 1].values[idx].value + this.getRandomNumber(0, maxJump)
      }
    });
    arr.push({
      name: `${namePrefix.prefix || ''} ${(namePrefix.initialValue || 0) + i}`,
      values
    });
  }
  return arr;
};

export default {
  getRandomNumber,
  generateData
}

mocks.js :

import helpers from './helpers';
const defaultChart = [
  {
    id: 1,
    label: 'Google',
    value: helpers.getRandomNumber(0, 50)
  },
  {
    id: 2,
    label: 'Facebook',
    value: helpers.getRandomNumber(0, 50)
  },
  {
    id: 3,
    label: 'Outbrain',
    value: helpers.getRandomNumber(0, 50)
  },
  {
    id: 4,
    label: 'Apple',
    value: helpers.getRandomNumber(0, 50)
  },
  {
    id: 5,
    label: 'Amazon',
    value: helpers.getRandomNumber(0, 50)
  },
];
export default {
  defaultChart,
}

一个乞丐版的动态排行榜可视化就做好喇。

8. 完整代码

import React, { useState, useEffect } from 'react';
import PropTypes from 'prop-types';
import './styles.scss';

const getRandomColor = () => {
  const letters = '0123456789ABCDEF';
  let color = '#';
  for (let i = 0; i  {
  return `translateY(${value}px)`;
}

const DynamicBarChart = (props) => {
  const [dataQueue, setDataQueue] = useState([]);
  const [activeItemIdx, setActiveItemIdx] = useState(0);
  const [highestValue, setHighestValue] = useState(0);
  const [currentValues, setCurrentValues] = useState({});
  const [firstRun, setFirstRun] = useState(false);
  let iterationTimeoutHolder = null;

  function start () {
    if (activeItemIdx > 1) {
      return;
    }
    nextStep(true);
  }

  function setNextValues () {
    if (!dataQueue[activeItemIdx]) {
      iterationTimeoutHolder = null;
      return;
    }

    const roundData = dataQueue[activeItemIdx].values;
    const nextValues = {};
    let highestValue = 0;
    roundData.map((c) => {
      nextValues[c.id] = {
        ...c,
        color: c.color || (currentValues[c.id] || {}).color || getRandomColor()
      };

      if (Math.abs(c.value) > highestValue) {
        highestValue = Math.abs(c.value);
      }

      return c;
    });
    console.table(highestValue);

    setCurrentValues(nextValues);
    setHighestValue(highestValue);
    setActiveItemIdx(activeItemIdx + 1);
  }

  function nextStep (firstRun = false) {
    setFirstRun(firstRun);
    setNextValues();
  }

  useEffect(() => {
    setDataQueue(props.data);
  }, []);

  useEffect(() => {
    start();
  }, [dataQueue]);

  useEffect(() => {
    iterationTimeoutHolder = window.setTimeout(nextStep, 1000);
    return () => {
      if (iterationTimeoutHolder) {
        window.clearTimeout(iterationTimeoutHolder);
      }
    };
  }, [activeItemIdx]);

  const keys = Object.keys(currentValues);
  const { barGapSize, barHeight, showTitle, data } = props;
  console.table('data', data);
  const maxValue = highestValue / 0.85;
  const sortedCurrentValues = keys.sort((a, b) => currentValues[b].value - currentValues[a].value);
  const currentItem = dataQueue[activeItemIdx - 1] || {};

  return (
    

      {
        
          {
            showTitle &&
            
{currentItem.name}
          }
          

            

              {
                sortedCurrentValues.map((key, idx) => {
                  const currentValueData = currentValues[key];
                  const value = currentValueData.value
                  let width = Math.abs((value / maxValue * 100));
                  let widthStr;
                  if (isNaN(width) || !width) {
                    widthStr = '1px';
                  } else {
                    widthStr = `${width}%`;
                  }

                  return (
                    

                      
                        {
                          !currentValueData.label
                            ? key
                            : currentValueData.label
                        }
                      
                      

                      {currentValueData.value}
                    
                  );
                })
              }
            
          
        
      }
    
  );
};

DynamicBarChart.propTypes = {
  showTitle: PropTypes.bool,
  iterationTimeout: PropTypes.number,
  data: PropTypes.array,
  startRunningTimeout: PropTypes.number,
  barHeight: PropTypes.number,
  barGapSize: PropTypes.number,
  baseline: PropTypes.number,
};

DynamicBarChart.defaultProps = {
  showTitle: true,
  iterationTimeout: 200,
  data: [],
  startRunningTimeout: 0,
  barHeight: 50,
  barGapSize: 20,
  baseline: null,
};

export {
  DynamicBarChart
};

styles.scss

.live-chart {
  width: 100%;
  padding: 20px;
  box-sizing: border-box;
  position: relative;
  text-align: center;
  h1 {
    font-weight: 700;
    font-size: 60px;
    text-transform: uppercase;
    text-align: center;
    padding: 20px 10px;
    margin: 0;
  }

  .chart {
    position: relative;
    margin: 20px auto;
  }

  .chart-bars {
    position: relative;
    width: 100%;
  }

  .bar-wrapper {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    position: absolute;
    top: 0;
    left: 0;
    transform: translateY(0);
    transition: transform 0.5s linear;
    padding-left: 200px;
    box-sizing: border-box;
    width: 100%;
    justify-content: flex-start;

    label {
      position: absolute;
      height: 100%;
      width: 200px;
      left: 0;
      padding: 0 10px;
      box-sizing: border-box;
      text-align: right;
      top: 50%;
      transform: translateY(-50%);
      font-size: 16px;
      font-weight: 700;
      display: flex;
      justify-content: flex-end;
      align-items: center;
    }

    .value {
      font-size: 16px;
      font-weight: 700;
      margin-left: 10px;
    }

    .bar {
      width: 0%;
      transition: width 0.5s linear;
    }
  }
}

原项目地址：react-dynamic-charts：https://dsternlicht.github.io/react-dynamic-charts/

结语

一直对实现动态排行榜可视化感兴趣，无奈多数都是基于 D3 或 echarts 实现。

而这个库，不仅脱离图形库，还使用了 React 16 的新特性。也让我彻底理解了 React Hook 的妙用。

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