Image

tsx
import { SolitoImage } from 'solito/image'

tsx
import { SolitoImage } from 'solito/image'

A drop-in replacement for the Next.js Image component.

On Web, it uses next/image. On iOS & Android, it uses react-native-fast-image by Dylan Vann.

Usage

You can use remote URLs:

tsx
<SolitoImage
  src="https://beatgig.com/image.png"
  height={100}
  width={100}
  alt="A cool artist's image."
/>

tsx
<SolitoImage
  src="https://beatgig.com/image.png"
  height={100}
  width={100}
  alt="A cool artist's image."
/>

You can use imported files:

tsx
import image from './image.png'
export const Image = () => (
  <SolitoImage
    src={image}
    height={100}
    width={100}
    alt="A cool image, imported locally."
  />
)

tsx
import image from './image.png'
export const Image = () => (
  <SolitoImage
    src={image}
    height={100}
    width={100}
    alt="A cool image, imported locally."
  />
)

And if you add some configuration, you can even use files from your Next.js website's public folder across platforms:

tsx
<SolitoImage
  src="/image.png"
  height={100}
  width={100}
  alt="A cool artist's image."
/>

tsx
<SolitoImage
  src="/image.png"
  height={100}
  width={100}
  alt="A cool artist's image."
/>

Props

Please reference the Next.js Image component. It's useful to get acquainted with how it works before using SolitoImage.

The following props are supported across platforms:

src
loader
width
height
quality
crossOrigin
referrerPolicy
alt
fill
onLoadingComplete
loading
priority
placeholder
blurDataURL (web only)
sizes
srcSet
style React Native style prop.
unoptimized

Styling

You can style the image using the style prop. It accepts a React Native style object.

tsx
<SolitoImage
  style={{
    borderRadius: 6,
    transform: [
      {
        scale: 1.2,
      },
    ],
  }}
/>

tsx
<SolitoImage
  style={{
    borderRadius: 6,
    transform: [
      {
        scale: 1.2,
      },
    ],
  }}
/>

`fill`

If fill is set to true, the image will fill the entire container with absolute position. You don't need to set height and width with fill.

tsx
<SolitoImage fill src="/my-image.png" />

tsx
<SolitoImage fill src="/my-image.png" />

Image Loaders

next/image lets you configure a loader function. solito/image brings this functionality to iOS & Android. This is where the power of optimized images comes in, so it's useful to understand how it works.

Say you use Cloudinary as your image CDN. Your loader would look like this:

tsx
<SolitoImage
  // this is your cloudinary image ID
  src="239409adf90.jpg"
  // these are your image's dimensions
  height={1600}
  width={900}
  quality={90}
  loader={({ quality, src, width }) => {
    const cloudinaryKey = `your-key`
    return `https://res.cloudinary.com/${cloudinaryKey}/image/upload/q_${quality},w_${width}/${src}`
  }}
/>

tsx
<SolitoImage
  // this is your cloudinary image ID
  src="239409adf90.jpg"
  // these are your image's dimensions
  height={1600}
  width={900}
  quality={90}
  loader={({ quality, src, width }) => {
    const cloudinaryKey = `your-key`
    return `https://res.cloudinary.com/${cloudinaryKey}/image/upload/q_${quality},w_${width}/${src}`
  }}
/>

Given a quality, src, and width, the loader generates an image URL. Let's examine each parameter.

src and quality are simple: they're the values passed as props. quality will be 90, and src will be 239409adf90.jpg.

width, however, is different. You might think that the width prop passed to the loader will be 900, since that's what we passed to the component. However, this is not the case.

The width prop passed to SolitoImage is meant to be the true width of the image file itself. But the width passed to the loader function could be any number.

Under the hood, the image component loops through many different image widths, creates a URL for each, and then chooses which one to use. Here's a pseudo-code example of what it does:

tsx
// think of it like this:
const imageUrls = [100, 200, 300, 400].map((width) =>
  loader({ quality, src, width })
)
// then it chooses the best one (again, this is pseudo-code)
<img src={imageUrls.find(bestImage)} />

tsx
// think of it like this:
const imageUrls = [100, 200, 300, 400].map((width) =>
  loader({ quality, src, width })
)
// then it chooses the best one (again, this is pseudo-code)
<img src={imageUrls.find(bestImage)} />

Once the image component has a set of URLs, it determines which one to use. On Web, this determination is done by the browser using the sizes and srcSet attributes on the <img /> element.

SolitoImage implements sizes and srcSet logic on iOS & Android using JS with screen dimensions to achieve feature parity with Web. (Source code)

To recap – loader is a convenient pure function to construct optimized URLs for your image.

Circumventing loader

If you don't want to use a loader, you can pass unoptimized to your image. It will use the src prop as-is.

tsx
<SolitoImage
  height={200}
  width={200}
  src="https://beatgig.com/image.png"
  unoptimized
/>

tsx
<SolitoImage
  height={200}
  width={200}
  src="https://beatgig.com/image.png"
  unoptimized
/>

Globally-configured loaders

Setting the loader prop on every image can get a bit tedious.

The Solito recommendation for configuring an image loader across your whole app is to use the <SolitoImageProvider />.

tsx
<SolitoImageProvider
  // all image children will default to this loader
  loader={({ quality, src, width }) => {
    const cloudinaryKey = `your-key`
    return `https://res.cloudinary.com/${cloudinaryKey}/image/upload/q_${quality},w_${width}/${src}`
  }}
>
  <App />
</SolitoImageProvider>

tsx
<SolitoImageProvider
  // all image children will default to this loader
  loader={({ quality, src, width }) => {
    const cloudinaryKey = `your-key`
    return `https://res.cloudinary.com/${cloudinaryKey}/image/upload/q_${quality},w_${width}/${src}`
  }}
>
  <App />
</SolitoImageProvider>

To learn more about global configuration, see the Configuration section.

Migrating from Next.js

If you're using a custom loaderFile in your next.config.js, you can pass the same loader function to SolitoImageProvider.

`public` folder

Next.js lets you add files to a public folder and reference them using a relative URL in your app.

For example, if you have public/image.jpg in your Next.js app, you can use it like so:

tsx
<img src="/image.jpg" />

tsx
<img src="/image.jpg" />

React Native's Image component doesn't have the same approach to static assets. You either need to provide an absolute URL, or import a static asset:

tsx
// ✅ React Native allows this
<Image source={{ uri: 'https://beatgig.com/some-image.png' }} />
// ✅ React Native allows this
<Image source={require('./image.png')} />
// ❌ React Native does not allow this
<Image src="/image.png" />

tsx
// ✅ React Native allows this
<Image source={{ uri: 'https://beatgig.com/some-image.png' }} />
// ✅ React Native allows this
<Image source={require('./image.png')} />
// ❌ React Native does not allow this
<Image src="/image.png" />

To keep the convenient APIs of Next.js, SolitoImage lets you use your website's public folder for images across platforms:

tsx
// ✅ SolitoImage allows this
<SolitoImage src="/image.png" />

tsx
// ✅ SolitoImage allows this
<SolitoImage src="/image.png" />

In the configuration section below, we'll see how this is possible.

Configuration

Since your images property from next.config.js won't apply to React Native, Solito has a SolitoImageProvider to define your config instead.

This provider lets you do things like query images on your app from your website's public folder.

To start, wrap your app in the SolitoImageProvider. Next provide a nextJsURL prop:

tsx
<SolitoImageProvider nextJsURL="https://beatgig.com">
  <App />
</SolitoImageProvider>

tsx
<SolitoImageProvider nextJsURL="https://beatgig.com">
  <App />
</SolitoImageProvider>

Under the hood, Solito will use the nextJsURL as the prefix for static assets that are defined as strings.

It's worth mentioning that images imported from the public folder will not get bundled as static assets in your iOS & Android apps. Instead, they will fetch from the network and then cache. If you want the images to bundle in your native app, you should import them directly.

`<SolitoImageProvider />`

You can think of SolitoImageProvider as your images configuration from next.config.js. It accepts the following props:

nextJsURL: (recommened) The URL of your Next.js app. This is used to prefix static assets that are defined as strings.
loader: Globally configure an image loader function. I recommend using this for simplifying your API. See the loaders docs.
deviceSizes: An array defining device sizes. Matches the same default as Next.js. See their docs.
imageSizes: An array defining image sizes. Matches the same default as Next.js. See their docs.

tsx
<SolitoImageProvider
  nextJsURL="https://beatgig.com"
  loader={({ quality, width, src }) => {
    return `https://cloudinary.com/${src}?w=${width}&q=${quality}`
  }}
>
  <App />
</SolitoImageProvider>

tsx
<SolitoImageProvider
  nextJsURL="https://beatgig.com"
  loader={({ quality, width, src }) => {
    return `https://cloudinary.com/${src}?w=${width}&q=${quality}`
  }}
>
  <App />
</SolitoImageProvider>

Installation

solito/image requires solito v2+.

Next.js

Add the images configuration to your next.config.js:

js
module.exports = {
  images: {
    disableStaticImages: true,
  },
}

js
module.exports = {
  images: {
    disableStaticImages: true,
  },
}

Expo

solito/image uses react-native-fast-image under the hood. Since this has native code, you have to use a custom dev client instead of Expo Go.

With a custom dev client (recommended)

sh
cd apps/expo
expo install react-native-fast-image
cd ../..
yarn
cd apps/expo
# install your native dependencies
npx expo prebuild
# build your development client
npx expo run:ios
# start the expo dev server for testing
npx expo start --dev-client --ios

sh
cd apps/expo
expo install react-native-fast-image
cd ../..
yarn
cd apps/expo
# install your native dependencies
npx expo prebuild
# build your development client
npx expo run:ios
# start the expo dev server for testing
npx expo start --dev-client --ios

With Expo Go

If you still want to use Expo Go, you can import from solito/image/expo instead. This uses React Native's vanilla Image component under the hood.

For a production app, I recommend using solito/image with react-native-fast-image and a custom dev client, since React Native's vanilla image is known to have bugs.

Vanilla React Native

After upgrading to Solito v2, you'll need to install react-native-fast-image.

sh
cd apps/expo # or wherever your react-native folder is
yarn add react-native-fast-image
npx pod-install
cd ../..
yarn

sh
cd apps/expo # or wherever your react-native folder is
yarn add react-native-fast-image
npx pod-install
cd ../..
yarn

Usage​

Props​

Styling​

fill​

Image Loaders​

Circumventing loader​

Globally-configured loaders​

Migrating from Next.js

public folder​

Configuration​

<SolitoImageProvider />​

Installation​

Next.js​

Expo​

With a custom dev client (recommended)​

With Expo Go​

Vanilla React Native​

Usage

Props

Styling

`fill`

Image Loaders

Circumventing loader

Globally-configured loaders

`public` folder

Configuration

`<SolitoImageProvider />`

Installation

Next.js

Expo

With a custom dev client (recommended)

With Expo Go

Vanilla React Native