useDimensions

useDimensions is a custom hook that measures dimensions of the referenced element based on its box-model.

Import

import { useDimensions } from '@chakra-ui/react'

Return value

This hook returns an object with the properties marginBox, paddingBox, borderBox, contentBox, border, padding, and margin.

Each of these properties contains a nested object which provides values respective to that property:

Value:	Contents:
marginBox	top, right, bottom, left, width, height, x, y, center (x, y)
borderBox	top, right, bottom, left, width, height, x, y, center (x, y)
paddingBox	top, right, bottom, left, width, height, x, y, center (x, y)
contentBox	top, right, bottom, left, width, height, x, y, center (x, y)
border	top, right, bottom, left
padding	top, right, bottom, left
margin	top, right, bottom, left

Usage

function example() {
  const elementRef = useRef()
  const dimensions = useDimensions(elementRef)

  return (
    <Box ref={elementRef} color='white' width='fit-content' bg='blue.700' p={4}>
      <Heading>
        <code>borderBox</code> dimensions
      </Heading>
      <List>
        <ListItem>
          The Width: {dimensions && dimensions.borderBox.width}
        </ListItem>
        <ListItem>
          The x coordinate: {dimensions && dimensions.borderBox.x}
        </ListItem>
      </List>
    </Box>
  )
}

With observe Parameter

With the second parameter set to true, the hook will attach the resize and scroll events to the window object. This will recalculate the reference element's dimensions on scroll or resize of the page.

function example() {
  const elementRef = useRef()
  const dimensions = useDimensions(elementRef, true)

  return (
    <>
      <Textarea
        ref={elementRef}
        value="Resize this field's height, then either scroll or resize the page."
      />
      <Box>Changing height: {dimensions && dimensions.borderBox.height}</Box>
    </>
  )
}

Parameters

Parameter	Type	Description
ref	RefObject<HTMLElement>	Reference to the element you want to measure
observe (optional)	boolean	If set to true, the resize and scroll events will be attached to the window and update the dimensions on each event