[docs] add avatar upload example

[Demianeen]

Related page

https://mui.com/material-ui/react-avatar/

Kind of issue

Missing information

Issue description

I recently needed to implement avatar upload inside form during sign up flow, I ended up with a bit hacky solution where I need to have visually hidden input nearby the clickable avatar, and that avatar will be a label, so that click on label will cause click on input. I also needed to put another hack in place so that input navigation with tab would work. It seems like quite popular usecase. Potentially adding section in the docs on how to implement it could save a lot of time and hacks in code to other people like me.

Just as the reference, this is what I end up with:

import { memo, useId, useState } from 'react'
import type { AvatarProps, FormHelperTextProps } from '@mui/material'
import { Avatar, FormHelperText, Stack, styled } from '@mui/material'
import PersonIcon from '@mui/icons-material/Person'
import { avatarConstraints } from '../../model/contact-info-schema'
import { useFocus } from '@/shared/lib/react/useFocus'
import { useTab } from '@/shared/lib/react/useTab'

const VisuallyHiddenInput = styled('input')({
	clip: 'rect(0 0 0 0)',
	clipPath: 'inset(50%)',
	height: 1,
	overflow: 'hidden',
	position: 'absolute',
	bottom: 0,
	left: 0,
	whiteSpace: 'nowrap',
	width: 1,
})

const ClickableAvatar = styled(Avatar)(({ theme }) => ({
	width: 100,
	height: 100,
	cursor: 'pointer',
	transition: 'all .1s',
	'&[data-focused="true"]': {
		outline: `4px solid ${theme.palette.primary.main}`, // Replace with your desired style
		outlineOffset: '4px',
	},
	'&:hover': {
		filter: 'brightness(90%)',
	},
	'&:active': {
		scale: 0.9,
	},
}))

type ClickableAvatarProps = Omit<AvatarProps<'label'>, 'component'>

interface AvatarUploadProps {
	avatarProps?: ClickableAvatarProps
	inputProps?: React.InputHTMLAttributes<HTMLInputElement>
	helperTextProps?: FormHelperTextProps
}

export const AvatarUpload = memo(function AvatarUpload({
	avatarProps,
	inputProps,
	helperTextProps,
}: AvatarUploadProps) {
	const [imageSrc, setImageSrc] = useState<string>()

	const id = useId()
	const [isInputFocused, bindFocus] = useFocus()
	const { isTabLastKey } = useTab()

	const handleImageChange = (event: React.ChangeEvent<HTMLInputElement>) => {
		const file = event.target.files?.[0]
		if (file) {
			// Read the file as a data URL
			const reader = new FileReader()
			reader.onload = () => {
				setImageSrc(reader.result as string)
			}
			reader.readAsDataURL(file)
		}

		inputProps?.onChange?.(event)
	}

	return (
		<Stack alignItems={'center'}>
			<ClickableAvatar
				// @ts-expect-error it can't see component prop for some reason
				component='label'
				role={undefined}
				variant='circular'
				src={imageSrc}
				htmlFor={id}
				data-focused={isInputFocused && isTabLastKey.current}
				{...avatarProps}
			>
				<PersonIcon
					sx={{
						fontSize: '40px',
					}}
				/>
			</ClickableAvatar>
			<VisuallyHiddenInput
				id={id}
				type='file'
				accept={avatarConstraints.type.join(', ')}
				multiple={false}
				{...inputProps}
				{...bindFocus}
				onChange={handleImageChange}
			/>
			<FormHelperText {...helperTextProps} />
		</Stack>
	)
})

useFocus.ts (just tracks focus of the elem):

import { useCallback, useMemo, useState } from 'react'

interface UseFocusBind {
	onBlur: () => void
	onFocus: () => void
}

export type UseFocusReturnType = [boolean, UseFocusBind]

/**
 * Tracks if an element is focused or not.
 * @returns {[boolean, {onBlur: () => void, onFocus: () => void}]}
 */
export const useFocus = (): UseFocusReturnType => {
	const [isFocused, setIsFocused] = useState(false)

	const onBlur = useCallback(() => {
		setIsFocused(false)
	}, [])

	const onFocus = useCallback(() => {
		setIsFocused(true)
	}, [])

	return useMemo(
		() => [isFocused, { onBlur, onFocus }],
		[isFocused, onBlur, onFocus],
	)
}

useTab(tracks if the tab key is the last pressed):

import { useEffect, useRef } from 'react'

/**
 * Custom React Hook to track if the Tab key was the last key pressed.
 *
 * This hook sets up global event listeners for 'keydown' and 'mousedown' events.
 * It updates a ref `isTabLastKey` to determine if the Tab key was the last key pressed.
 * The use of a ref prevents unnecessary re-renders of your component when these events occur.
 *
 * @returns {Object} - An object containing:
 *   - `isTabLastKey` (Ref<boolean>): A ref that is `true` if the last key pressed was Tab, `false` otherwise.
 *
 * @example
 * const { isTabLastKey } = useTab();
 * // You can now use isTabLastKey.current in your component logic
 */
export const useTab = () => {
	const isTabLastKey = useRef(false)

	useEffect(() => {
		const handleKeyDown = (event: KeyboardEvent) => {
			if (event.key === 'Tab') {
				isTabLastKey.current = true
			} else {
				isTabLastKey.current = false
			}
		}

		const handleMouseDown = () => {
			isTabLastKey.current = false
		}

		window.addEventListener('keydown', handleKeyDown)

		window.addEventListener('mousedown', handleMouseDown)

		return () => {
			window.removeEventListener('keydown', handleKeyDown)
			window.removeEventListener('click', handleMouseDown)
		}
	}, [])

	return { isTabLastKey }
}

Context

No response

Search keywords: mui avatar profile upload input hidden

[DiegoAndai]

Hey @Demianeen, thanks for reaching out!

This would be useful. I added the ready to take label in case anyone wants to work on this before the team gets to it. Please let me know if you're interested, and I'll gladly guide you.

Just a note for anyone working on this: I think we need to find a more straightforward way to achieve the demo, as the code shared in the description is a bit intricate for a demo.

[Demianeen]

I never added stuff like this to the docs, but I am happy to try! The only thing is that I agree that code is a bit too complicated for a demo. Does mui has some helper functions that I can look into that can help to remove useTab or useFocus? It would remove almost half of the code

Also, there is an @ts-expect-error in the component itself, I am not sure if I would be able to fix that types issue. Should we do anything about it?

[DiegoAndai]

@Demianeen I would suggest using ButtonBase, here's how IconButton uses it, for example:

material-ui/packages/mui-material/src/IconButton/IconButton.js

Line 37 in a0fa7c1

const IconButtonRoot = styled(ButtonBase, {

ButtonBase is intended to be a building block for buttons, and handles focus and keyboard navigation.

About the @ts-expect-error, I think we can remove it with this workaround: #44931 (comment)

Let me know if it works 👍🏼

[Demianeen]

Thanks for pointers! I managed to remove dependency on additional hooks:

import type { ElementType } from 'react'
import { forwardRef, memo, useImperativeHandle, useRef, useState } from 'react'
import type {
	AvatarProps,
	ButtonBaseProps,
	FormHelperTextProps,
} from '@mui/material'
import { Avatar, ButtonBase, FormHelperText, styled } from '@mui/material'
import PersonIcon from '@mui/icons-material/Person'

const VisuallyHiddenInput = styled('input')({
	display: 'none',
})

const ClickableAvatarWrapper = styled(ButtonBase)<
	ButtonBaseProps & { component: ElementType }
>(({ theme }) => ({
	width: 100,
	height: 100,
	cursor: 'pointer',
	transition: 'all .1s',
	borderRadius: '50%',
	'&.Mui-focusVisible': {
		outline: `4px solid ${theme.palette.primary.main}`,
		outlineOffset: '4px',
	},
}))

const ClickableAvatar = styled(Avatar)(() => ({
	width: 100,
	height: 100,
	'&:hover': {
		filter: 'brightness(90%)',
	},
}))

interface AvatarUploadProps {
	avatarProps?: AvatarProps
	inputProps?: React.InputHTMLAttributes<HTMLInputElement>
	helperTextProps?: FormHelperTextProps
}

export const AvatarUpload = memo(
	forwardRef<HTMLInputElement, AvatarUploadProps>(function AvatarUpload(
		{ avatarProps, inputProps, helperTextProps },
		ref,
	) {
		const [imageSrc, setImageSrc] = useState<string>()
		const inputRef = useRef<HTMLInputElement>(null)

		useImperativeHandle(ref, () => inputRef.current!)

		const handleImageChange = (event: React.ChangeEvent<HTMLInputElement>) => {
			const file = event.target.files?.[0]
			if (file) {
				// Read the file as a data URL
				const reader = new FileReader()
				reader.onload = () => {
					setImageSrc(reader.result as string)
				}
				reader.readAsDataURL(file)
			}

			inputProps?.onChange?.(event)
		}

                // https://stackoverflow.com/questions/75121073/unable-to-trigger-input-event-from-label-element-with-keyboard
		const handleKeyDown = (event: React.KeyboardEvent<HTMLSpanElement>) => {
			if (event.key === 'Enter' || event.key === ' ') {
				event.preventDefault()
				inputRef.current?.click()
			}
		}

		return (
			<ClickableAvatarWrapper
				component='label'
				tabIndex={0}
				role='button'
				onKeyDown={handleKeyDown}
			>
				<ClickableAvatar
					variant='circular'
					src={imageSrc}
					{...avatarProps}
				>
					<PersonIcon
						sx={{
							fontSize: '40px',
						}}
					/>
				</ClickableAvatar>
				<VisuallyHiddenInput
					type='file'
					accept={'image/png, image/jpg, image/jpeg'}
					multiple={false}
					{...inputProps}
					// those props couldn't be overridden directly, but you still can use on change or ref
					onChange={handleImageChange}
					ref={inputRef}
				/>
				<FormHelperText {...helperTextProps} />
			</ClickableAvatarWrapper>
		)
	}),
)

The only other thing I am unsure about is form helper text, because I use label here for focus and not the input itself, user wouldn't be able to focus on hidden input. I am not sure if FormHelperText will be accessible with this approach. What do you think?