useFavicon

A simple react hook to show a dynamic favicon

Getting Started

Install and run the dev server

yarn && yarn dev

Open http://localhost:3000 with your browser to see the result.

Gimme the code

Open the utils/hooks/useFavicon.ts and copy that file over and boom you have it.

How to use?

Let's say we want to show FUCKYOU letter by letter in our favicon

const Example = () => {
  const [tick, setTick] = useState(0)

  useEffect(() => {
    // Tick every 1s
    const subs = setInterval(() => {
      setTick((_tick) => _tick + 1)
    }, 1000)

    return () => {
      clearInterval(subs)
    }
  }, [])

  const drawFavicon: FaviconDrawFunc = useCallback(
    (context) => {
      const array = 'FUCKYOU.'.split('')
      const idx = tick % array.length
      console.log(idx)
      if (array[idx] === '.') {
        return `https://fav.farm/🌚`
      }
      context.font = '180px Arial'
      context.fillStyle = '#fff'
      context.textAlign = 'center'
      context.textBaseline = 'middle'
      context.fillText(array[idx], 100, 100)

      return true
    },
    [tick]
  )

  const options = useMemo(
    () => ({
      defaultIcon: '/favicon.ico',
      autoSetIcon: true
    }),
    []
  )

  const iconURL = useFavicon(drawFavicon, options)

  return null
}

NOTE: Do remember the useCallback and useMemo because every time your draw function or options change the icon is created again

The hook returns the icon url so if you are using some library to manage head tags

Options

Option	Type	Default	Info
defaultIcon	string	null	Default icon url to be shown (mainly used if using SSR)
width	number	200	Width of the canvas
height	number	200	Height of the canvas
autoSetIcon	boolean	false	If the hook should automatically update the favicon
linkTagSelector	string	link[rel="shortcut icon"]	The selector to select the favicon link tag. Used if autoSetIcon is true