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react-strapi-img
npm i react-strapi-img
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react-strapi-img

react-strapi-img is a wrapper for images, that handles responsive sizes, lazyloading and loading-animation. It is built to consume the image-data from Strapi.

by Andreas Faust

0.2.3 (see all)License:MITTypeScript:Built-In
npm i react-strapi-img
Readme

react-strapi-img

react-strapi-img is a wrapper for img, that handles webp-support, responsive sizes, lazyloading and loading-animation. It is optimized to consume image-data from Strapi, but can be useful in other contexts as well.

🦊 Take a look at the example.

⚠️ This library is in beta-state, which means its API still can change a bit without warning. Everything is working great so far, but it still needs some testing. As soon as I tested it in production and gathered some feedback, I will release verson 1.0.0. Feel free to join and improve!

What it does

  • Wrap image in proportional container, to preserve and determine height.
  • Lazyload image.
  • Transform Strapi image-formats-object into srcset.
  • Add Blured, animated base64-placeholder.
  • Use WebP-format if supported.
  • Add noscript-image for SEO.
  • Decode images before rendering for better performance.

PeerDependencies

  • react: >= 16.8.0,
  • react-dom: >= 16.8.0,
  • styled-components: >= 5.2.0

Why another image-loader?

I could not find an existing solution, that connects resized images from Strapi with NextJS conveniently and meets all my requirements.


Install

yarn add react react-dom styled-components react-strapi-img
npm install -S react react-dom styled-components react-strapi-img

Setup image-resizing in Strapi

To gain the efficency of srcset, copy the folder services to the Strapi-folder /extensions/upload. The scripts will resize every uploaded image:

  1. to base64
  2. to sizes from 400px to the original image width in steps of 200px – maximum is 3000px — the original image-size will be added as largest breakpoint

This method is gratefully adapted from here: https://sarpisik.com/blog/how-to-generate-different-image-formats-with-strapi-plugin-upload-part-ii

In react fetch the image with graphQL:

query {
  image {
    url
    alternativeText
    width
    height
    formats
  }
}

Usage

After setting up Strapi and uploading some images, use them in your react-components:

import React from "react";
import Image, { Types } from "react-strapi-img";

interface Props {
  imageFromStrapi: Types.ImageProps;
}

const MyApp: React.FC<Props> = ({ imageFromStrapi }) => {
  const { url, alternativeText, width, height, formats } = imageFromStrapi;
  return (
    <Image
      // you could also spread all props like this: {...imageFromStrapi},
      // but for the purpose of demonstration I am adding them one by one
      url={url} // required
      alternativeText={alternativeText} // optional
      width={width} // optional
      height={height} // optional
      formats={formats} // optional
      prefix={
        process.env.NODE_ENV === "production"
          ? "https://api.myapp.net"
          : "http://localhost:1337"
      } // optional
    />
  );
};

export default MyApp;

Props

Except url all props are optional.

NameTypeDefaultDescription
urlstringImage-url. Fetch with Strapi.
formatsobjectStrapi provides a formats-object for srcset and base64. Fetch it and insert it here.
sizesstringsizes-Tag. Help browsers to make better decisions. https://css-tricks.com/a-guide-to-the-responsive-images-syntax-in-html/
objectFitstring'cover'CSS-property. Useful together with proportionalHeight
objectPositionstring'center'CSS-property. Useful together with proportionalHeight
widthnumberProvided by Strapi. Pass it to preserve original image-proportions.
heightnumberProvided by Strapi. Pass it to preserve original image-proportions.
proportionalHeightnumberProvide for custom image-proportion. Crops image. Use along with objectFit and objectPosition.
placeholderbooleantrueShow base64-Placeholder.
rootMarginstring50pxUsed by Intersection Observer to determine distance from viewport, when the image should be loaded
thresholdnumber0Value between 0 and 1. Used by Intersection Observer to indicate at what percentage of the target's visibility the observer's callback should be executed.
alternativeTextstringalt-Attribute of the image. Provided by Strapi. Pass it for good SEO.
classNamestringCustom className for the wrapping div-tag.
stylestringCustom styles for wrapper. styled-components template-literal.
stylePlaceholderstringCustom styles for placeholder-img. styled-components template-literal
styleImgstringCustom styles for img-tag. styled-components template-literal
prefixstringPrefix all src and srcset.
onLoadfunctionImage-onLoad-callback.
onErrorfunctionImage-onError-callback.

ImageProvider

Optionally you can wrap your App in the component ImageProvider, which lets you determine repeating settings at a central spot. Have a look at this _app.tsx from a nextJS-project:

import React from "react";
import { ImageProvider } from "react-strapi-img";

function MyApp({ Component, pageProps, router }) {
  return (
    <ImageProvider
      prefix={process.env.productionPath}
      style={`border: 10px solid red;`}
      onLoad={(event) => console.log(event.target)}
    >
      <Component {...pageProps} key={router.route} />
    </ImageProvider>
  );
}

export default MyApp;

Additionally the ImageProvider detects webp-support once, which gives the Image-Components a tiny performance boost.

ImageProvider-Props

All props are optional. You can find them here at "ContextProps".


TypeScript-Types

All relevant Types are exported:

  1. ImageProps
  2. ProviderProps
  3. Formats
  4. ObjectFit
import { Types } from "react-strapi-img";

interface Props {
  imageFromStrapi: Types.ImageProps;
}

const MyApp: React.FC<Props> = ({ imageFromStrapi }) => {
  return <Image {...imageFromStrapi} />;
};

export default MyApp;

Rendered Output

Initially:

<div class="Wrapper__StyledImageWrapper-sc-1o399dd-0 cqCfje imageWrapper">
  <img
    src="data:image/jpeg;base64,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"
    alt='Placeholder for the image "testimg_1d61597ba3.jpg".'
    class="Placeholder__StyledPlaceholder-h5tses-0 grjLdz"
  />
  <img
    src="data:image/gif;base64,R0lGODlhAQABAIAAAP///wAAACH5BAEAAAAALAAAAAABAAEAAAICRAEAOw=="
    alt="This is testimg_1d61597ba3.jpg"
    class="StyledImage-yw93u6-0 bvBGFq no-js-testimg_1d61597ba3"
  />
  <noscript>
    <style>
      .no-js-testimg_1d61597ba3 {
        display: none !important;
      }
    </style>
    <img
      src="testimg_1d61597ba3.jpg"
      alt="This is testimg_1d61597ba3.jpg"
      class="StyledImage-yw93u6-0 bvBGFq"
    />
  </noscript>
</div>

After image was loaded:

<div class="Wrapper__StyledImageWrapper-sc-1o399dd-0 cOGFGG imageWrapper">
  <img
    src="testimg_1d61597ba3.jpg"
    alt="This is testimg_1d61597ba3.jpg"
    class="StyledImage-yw93u6-0 bvBGFq no-js-testimg_1d61597ba3"
    srcset="
      /400_testimg_1d61597ba3.webp   400w,
      /600_testimg_1d61597ba3.webp   600w,
      /800_testimg_1d61597ba3.webp   800w,
      /1000_testimg_1d61597ba3.webp 1000w,
      /1200_testimg_1d61597ba3.webp 1200w,
      /1400_testimg_1d61597ba3.webp 1400w,
      /1600_testimg_1d61597ba3.webp 1600w,
      /1800_testimg_1d61597ba3.webp 1800w,
      /2000_testimg_1d61597ba3.webp 2000w,
      /2200_testimg_1d61597ba3.webp 2200w,
      /2400_testimg_1d61597ba3.webp 2400w,
      /2600_testimg_1d61597ba3.webp 2600w,
      /2800_testimg_1d61597ba3.webp 2800w,
      /3000_testimg_1d61597ba3.webp 3000w
    "
  />
  <noscript>
    <style>
      .no-js-testimg_1d61597ba3 {
        display: none !important;
      }
    </style>
    <img
      src="testimg_1d61597ba3.jpg"
      srcset="
        /400_testimg_1d61597ba3.webp   400w,
        /600_testimg_1d61597ba3.webp   600w,
        /800_testimg_1d61597ba3.webp   800w,
        /1000_testimg_1d61597ba3.webp 1000w,
        /1200_testimg_1d61597ba3.webp 1200w,
        /1400_testimg_1d61597ba3.webp 1400w,
        /1600_testimg_1d61597ba3.webp 1600w,
        /1800_testimg_1d61597ba3.webp 1800w,
        /2000_testimg_1d61597ba3.webp 2000w,
        /2200_testimg_1d61597ba3.webp 2200w,
        /2400_testimg_1d61597ba3.webp 2400w,
        /2600_testimg_1d61597ba3.webp 2600w,
        /2800_testimg_1d61597ba3.webp 2800w,
        /3000_testimg_1d61597ba3.webp 3000w
      "
      alt="This is testimg_1d61597ba3.jpg"
      class="StyledImage-yw93u6-0 bvBGFq"
    />
  </noscript>
</div>

Contributing

Every contribution is very much appreciated. You are invited to join me in making this software reliable and performant for everyone.

If react-strapi-img is helpful for you, don't hesitate to star it on GitHub.


License

Licensed under the MIT License, Copyright © 2020-present Andreas Faust. See LICENSE for more information.


Thanks

I want to give special thanks to Sarp for the Strapi-groundwork and Welly for his library react-cool-img, from which I learned and adapted a lot.