skip to Main Content

How can we achieve automatic updating of chart data in a chart component wrapped with React?

For example, the data I requested from backend will change and I want to update it whever it changes.

I tried to look up the documents of some chart library, but didn’t find the answer.

2

Answers


  1. If you are passing a state with data to a line chart or any other chart from react-chartjs-2, it gets automatically updated.
    Here is a basic example, hopefully, it makes sense for you.

    import React, { useState, useEffect } from 'react';
    import { Line } from 'react-chartjs-2';
    
    function ChartComponent() {
      const [chartData, setChartData] = useState({
        labels: [],
        datasets: [
          {
            label: 'Data Series',
            data: [],
            borderColor: 'rgba(75,192,192,1)',
            borderWidth: 1,
            fill: false,
          },
        ],
      });
    
      useEffect(() => {
        // Function to fetch data from your backend
        const fetchData = async () => {
          try {
            const response = await fetch('your-backend-endpoint');
            const data = await response.json();
    
            // Extract relevant data from the response and update the chartData
            const newLabels = data.map(entry => entry.label);
            const newDataPoints = data.map(entry => entry.value);
    
            setChartData({
              labels: newLabels,
              datasets: [
                {
                  ...chartData.datasets[0], // Keep other properties as they are
                  data: newDataPoints,
                },
              ],
            });
          } catch (error) {
            console.error('Error fetching data:', error);
          }
        };
    
        fetchData();
      }, []);
    
      return (
        <div>
          <Line data={chartData} />
        </div>
      );
    }
    
    export default ChartComponent;
    
    Login or Signup to reply.
  2. Solution

    In VChart, you can update the chart by calling either updateSpec or updateData.
    enter image description here

    To update the chart data, you can save the chart instance using ref when initializing the chart instance in a React component. Then, use useEffect to set the dependencies to the data that needs to be updated, and call the chart instance’s updateData method in the callback function.

    VChart also provides a React-VChart wrapper:

    https://www.visactor.io/vchart/guide/tutorial_docs/Cross-terminal_and_Developer_Ecology/react

    You can refer to the code example below to update the chart data using React-VChart.

    Code Example

    Clicking the "Update the data of bar chart" button allows for the updating of the chart’s data.

    import "./styles.css";
    import { BarChart } from "./BarChart";
    import { LineChart } from "./LineChart";
    import { AreaChart } from "./AreaChart";
    import { getBarData } from "./bar-data";
    import { useState } from "react";
    
    const colorMaps = {
      default: [
        "#6690F2",
        "#70D6A3",
        "#B4E6E2",
        "#63B5FC",
        "#FF8F62",
        "#FFDC83",
        "#BCC5FD",
        "#A29BFE",
        "#63C4C7",
        "#F68484"
      ],
      red: [
        "#c12e34",
        "#e6b600",
        "#0098d9",
        "#2b821d",
        "#005eaa",
        "#339ca8",
        "#cda819",
        "#32a487"
      ]
    };
    
    export default function App() {
      const [barData, setBarData] = useState<any[]>(getBarData());
      const [colors, setColors] = useState<string[]>(colorMaps.default);
      const handleUpdateBarData = () => {
        setBarData(getBarData());
      };
    
      const handleUpdateColors = () => {
        if (colors === colorMaps.default) {
          setColors(colorMaps.red);
        } else {
          setColors(colorMaps.default);
        }
      };
    
      return (
        <div className="App">
          <div>
            <img src="https://lf9-dp-fe-cms-tos.byteorg.com/obj/bit-cloud/logo_500_200_light.png" />
          </div>
          <button onClick={handleUpdateBarData}>
            Update the data of bar chart
          </button>
    
          <button onClick={handleUpdateColors}>update colors</button>
    
          <h2>A Bar Chart</h2>
    
          <BarChart data={barData} colors={colors} />
    
          <h2>A Line Chart</h2>
          <LineChart colors={colors} />
    
          <h2>A Area Chart</h2>
          <AreaChart colors={colors} />
        </div>
      );
    }
    

    Results

    Online demo:https://codesandbox.io/s/visactor-vchart-react-demo-forked-jsqqjj

    enter image description here

    Related Documentation

    react-vchart Tutorial:https://www.visactor.io/vchart/guide/tutorial_docs/Cross-terminal_and_Developer_Ecology/react

    github:https://github.com/VisActor/VChart

    Login or Signup to reply.
Please signup or login to give your own answer.
Back To Top
Search