React Progressive Image

react-progressive-image React component for progressive image loading

Install

$ yarn add react-progressive-image

The UMD build is also available on unpkg:

<script src="https://unpkg.com/react-progressive-image@0.1.0/umd/react-progressive-image.min.js"></script>

If you use the UMD build you can find the library on window.ReactProgressiveImage.

Examples

Simple

<ProgressiveImage src="large-image.jpg" placeholder="tiny-image.jpg">
  {src => <img src={src} alt="an image" />}
</ProgressiveImage>

With Delay

<ProgressiveImage
  delay={3000}
  src="large-image.jpg"
  placeholder="tiny-image.jpg"
>
  {src => <img src={src} alt="an image" />}
</ProgressiveImage>

With loading argment

<ProgressiveImage src="large-image.jpg" placeholder="tiny-image.jpg">
  {(src, loading) => (
    <img style={{ opacity: loading ? 0.5 : 1 }} src={src} alt="an image" />
  )}
</ProgressiveImage>

With srcSet

<ProgressiveImage
  src="medium.jpg"
  srcSetData={{
    srcSet: 'small.jpg 320w, medium.jpg 700w, large.jpg 2000w',
    sizes: '(max-width: 2000px) 100vw, 2000px'
  }}
  placeholder="tiny-image.jpg"
>
  {(src, _loading, srcSetData) => (
    <img
      src={src}
      srcSet={srcSetData.srcSet}
      sizes={srcSetData.sizes}
      alt="an image"
    />
  )}
</ProgressiveImage>

Progressive Enhancement and No JavaScript

Since this component relies on JavaScript to replace the placeholder src with the full image src, you should use a fallback image if your application supports environments that do not have JavaScript enabled or is progressively enhanced.

You can do this by adding the fallback image inside of a <noscript> tag in the render callback you provide as the ProgressiveImage component's child.

<ProgressiveImage src="large-image.jpg" placeholder="tiny-image.jpg">
  {src => {
    return (
      <div>
        <img className="progressive-image" src={src} />
        <noscript>
          <img className="progressive-image no-script" src="large-image.jpg" />
        </noscript>
      </div>
    );
  }}
</ProgressiveImage>

Props

Name	Type	Required	Description
children	function	true	returns src, loading, and srcSetData
delay	number	false	time in milliseconds before src image is loaded
onError	function	false	returns error event
placeholder	string	true	the src of the placeholder image
src	string	true	the src of the main image
srcSetData	{srcSet: "string", sizes: "string" }	false	srcset and sizes to be applied to the image