react-grid-heatmap

react-grid-heatmap

A React component to visualize heatmap in a grid layout without using any 3rd party libraries.

Demo - Try in Sandbox

Install

npm install --save react-grid-heatmap

Usage

Mandatory fields

Name	Type	Sample
data	number[][]	[[1,2,3], [4,5,6], [7,8,9]]

import React from 'react'
import { HeatMapGrid } from 'react-grid-heatmap'

const xLabels = new Array(24).fill(0).map((_, i) => `${i}`)
const yLabels = ['Sun', 'Mon', 'Tue', 'Wed', 'Thu', 'Fri']
const data = new Array(yLabels.length)
  .fill(0)
  .map(() =>
    new Array(xLabels.length).fill(0).map(() => Math.floor(Math.random() * 50 + 50))
  )

const App = () => {
  return (
    <HeatMapGrid
      data={data}
      xLabels={xLabels}
      yLabels={yLabels}
    />
  )
}

export default App

Optional Parameters

Name	Type	Description/Example	Default Value
xLabels	string[]	['1am', '2am', '3am']	null
yLabels	string[]	['Sun', 'Mon']	null
cellHeight	string	Height of each cell of the heatmap	"2rem"
onClick	function	Adds an handler to cell click (x, y) => void	null
square	boolean	If set to true will render cells as square	false
xLabelsPos	string	Location of y labels. It can be top or bottom	"top"
yLabelsPos	string	Location of y labels. It can be left or right	"left"
cellRender	function	Render custom content in cell. (x, y, value) => ()	null
cellStyle	function	To set custom cell style (x, y, ratio) => {}	null
xLabelsStyle	function	To set custom cell style (index) => {}	null
yLabelsStyle	function	To set custom cell style (index) => {}	null

A sample code with all parameters

import React from 'react'
import { HeatMapGrid } from 'react-grid-heatmap'

const xLabels = new Array(24).fill(0).map((_, i) => `${i}`)
const yLabels = ['Sun', 'Mon', 'Tue', 'Wed', 'Thu', 'Fri']
const data = new Array(yLabels.length)
  .fill(0)
  .map(() =>
    new Array(xLabels.length)
      .fill(0)
      .map(() => Math.floor(Math.random() * 50 + 50))
  )

const App = () => {
  return (
    <div
      style={{
        width: '100%'
      }}
    >
      <HeatMapGrid
        data={data}
        xLabels={xLabels}
        yLabels={yLabels}
        // Render cell with tooltip
        cellRender={(x, y, value) => (
          <div title={`Pos(${x}, ${y}) = ${value}`}>{value}</div>
        )}
        xLabelsStyle={(index) => ({
          color: index % 2 ? 'transparent' : '#777',
          fontSize: '.8rem'
        })}
        yLabelsStyle={() => ({
          fontSize: '.7rem',
          textTransform: 'uppercase',
          color: '#777'
        })}
        cellStyle={(_x, _y, ratio) => ({
          background: `rgb(12, 160, 44, ${ratio})`,
          fontSize: '.8rem',
          color: `rgb(0, 0, 0, ${ratio / 2 + 0.4})`
        })}
        cellHeight='2rem'
        xLabelsPos='bottom'
        onClick={(x, y) => alert(`Clicked (${x}, ${y})`)}
        yLabelsPos='right'
        square
      />
    </div>
  )
}

export default App

Local development

Local development is broken into two parts (ideally using two tabs).

First, run rollup to watch your src/ module and automatically recompile it into dist/ whenever you make changes.

npm start # runs rollup with watch flag

The second part will be running the example/ create-react-app that's linked to the local version of your module.

# (in another tab) 
cd example
npm start # runs create-react-app dev server 

Now, anytime you make a change to your library in src/ or to the example app's example/src, create-react-app will live-reload your local dev server so you can iterate on your component in real-time.

License

MIT © arunghosh