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    react-progressive-graceful-image
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    0.7.0 • Public • Published

    React Progressive Graceful Image

    Note: I published this interesting article on medium to explain the idea and motivation behind building this npm package. And a small code snippet to make best use of it.

    Update

    • [0.7.0] : Allow ^v18 of react and react-dom as peer dependencies, add + fix props types.
    • [0.6.14] : Allow ^v17 of react and react-dom as peer dependencies.
    • [0.6.13] : onError bug-fix to works as expected.

    Note: This is a forked repo from https://github.com/FormidableLabs/react-progressive-image. So, all usage are similar to that.

    I am adding two new features:

    • Graceful loading
    • Lazy loading

    similar to https://github.com/linasmnew/react-graceful-image, but with a different approach(for better performance and optimization). So, please check usage of 4 newly introduced props (noRetry, noLazyLoad, rootMargin, threshold) from the props table below.

    [TODO] :

    • [x] Use of Intersection Observer for Lazy Loading (Better Performance)
    • [x] Use of navigator.onLine in place of current retry strategy (Optimization)
    • [x] Introduce rootMargin and threshold props for Intersection Observer options.
    • [x] Add more Code Sandbox example links
    • [x] Remove ref from child function.
    • [ ] Remove dependency of @researchgate/react-intersection-observer

    Note: npm i intersection-observer, if polyfill is required, I have removed it to keep the library lightweight.


    Maintenance Status

    react-progressive-graceful-image React component for progressive image loading

    Install

    $ npm i react-progressive-graceful-image

    Examples

    Simple - CodeSandbox

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

    With Delay - CodeSandbox

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

    With loading argument - CodeSandbox

    <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 - CodeSandbox

    <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>

    With Intersection Observer Options - CodeSandbox

    <ProgressiveImage
      delay={3000}
      src="large-image.jpg"
      placeholder="tiny-image.jpg"
      rootMargin="0% 0% 0%"
      threshold={[1]}
    >
      {(src) => <img src={src} alt="an image" />}
    </ProgressiveImage>

    Component As Placeholder - CodeSandbox

    If you want to use a component, such as a loading spinner, as a placeholder, you can make use of the loading argument in the render callback. It will be true while the main image is loading and false once it has fully loaded. Keep in mind that the placeholder props is required, so you will need to explicitly declare an empty string as it's value if you plan on using a component in the render callback.

    const dominantImageColor = '#86356B';
    const placeholder = (
      <div
        style={{ backgroundColor: dominantImageColor, height: 300, width: 500 }}
      />
    );
    
    <ProgressiveImage src="large-image.jpg" placeholder="" >
      {(src, loading) => {
        return loading ? placeholder : <img src={src} 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 | React.Node true the img src or React Component for 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
    noRetry boolean false flag to turn off re-trying (default: false)
    noLazyLoad boolean false flag to turn off lazy loading (default: false)
    rootMargin string false Intersection Observer Option (eg: "0% 0% 25%" -default)
    threshold number|Array<number> false Intersection Observer Option (eg: [0] -default)

    Maintenance Status

    Stable: Formidable is not planning to develop any new features for this project. We are still responding to bug reports and security concerns. We are still welcoming PRs for this project, but PRs that include new features should be small and easy to integrate and should not include breaking changes.

    License

    Licensed under the MIT License, Copyright © 2019-present.

    See LICENSE for more information.

    Install

    npm i react-progressive-graceful-image

    DownloadsWeekly Downloads

    3,128

    Version

    0.7.0

    License

    MIT

    Unpacked Size

    42.9 kB

    Total Files

    15

    Last publish

    Collaborators

    • sanishkr