How to create a loading and error state placeholder for images?
TL;DR
Check the full code here
Long version
Creating a basic image
next/image
provides an easy way to create an image.
import Image from 'next/image'
<Image src="https://i.imgur.com/gf3TZMr.jpeg" alt="Some alt text" />
However, we still need to configure some properties to cater to our specific needs, such as:
- A placeholder when loading
- An error placeholder when the image fails to load
The GIF below shows what a user will see for an image loaded using a slow internet connection.
It gives the impression that something is wrong with our app.
How to handle the loading state?
Simply adding the placeholder
and blurDataURL
will do the trick.
<Image
src="https://i.imgur.com/gf3TZMr.jpeg"
placeholder="blur"
blurDataURL="/assets/image-placeholder.png"
/>
The code will yield the following result:
There's a brief delay before the placeholder is loaded
because even the placeholder image needs to be fetched from the server.
If we need to make sure that there's an immediate placeholder to the image,
refer to this guide on how to create a dynamic image placeholder
The good thing is that once the placeholder image is loaded, all other images that use the same asset
will display the placeholder immediately.
What happens if there's an error when loading the image
One possibility is that the user will stare at the placeholder for eternity.
Or this sadder version which shows the alt
and much space.
It is not fun to see too much unnecessary space, is it?
How to display another image during an error state?
We can replace the value of src
with the path to error image
in the onError
callback when an error happens.
const [src, setSrc] = React.useState('https://i.imgur.com/gf3TZMr.jpeg');
<Image
{...props}
src={src}
placeholder="blur"
blurDataURL="/assets/image-placeholder.png"
onError={() => setSrc('/assets/image-error.png')}
/>
I believe it's much better.
Putting all the code together
To make the behavior easy to replicate, we can create a custom image component.
function CustomImage({alt, ...props}) {
const [src, setSrc] = React.useState(props.src);
return (
<Image
{...props}
src={src}
alt={alt} // To fix lint warning
onError={() => setSrc('/assets/image-error.png')}
placeholder="blur"
blurDataURL="/assets/image-placeholder.png"
/>
);
}
Conclusion
When a web application displays many images, it is a good idea to give immediate feedback to the user of what is happening. One way to address this is to use an alternate image to show the current state of an image.
Top comments (3)
Thanks for your good posting.
Btw, I have problem with same code.
When I check this one with storybook, onError() doesn't work even though the url is wrong(occurs 404 error).
Can you help me to solve it?
Wow this is wonderful,an addition.... Generating the blurdata of each image when uploading will make sense when placed in the BlurDataUrl prop
cool