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__snapshots__ | ||
android | ||
docs | ||
example | ||
ios | ||
server | ||
.babelrc | ||
.gitignore | ||
.gitmodules | ||
.npmignore | ||
FastImage.js | ||
FastImage.test.js | ||
LICENSE | ||
README.md | ||
circle.yml | ||
index.d.ts | ||
package.json | ||
yarn.lock |
README.md
FastImage
🚩 FastImage, performant React Native image component.
Comparing FastImage to Image in the example app.
React Native's Image
component handles image caching like browsers
for the most part.
If the server is returning proper cache control
headers for images you'll generally get the sort of built in
caching behavior you'd have in a browser.
Even so many people have noticed:
- Flickering.
- Cache misses.
- Low performance loading from cache.
- Low performance in general.
FastImage
is an Image
replacement that solves these issues.
FastImage
is a wrapper around
SDWebImage (iOS)
and
Glide (Android).
Features
- Aggressively cache images.
- Add authorization headers.
- Prioritize images.
- Preload images.
- GIF support.
- Border radius property.
Usage
yarn add react-native-fast-image
react-native link
import FastImage from 'react-native-fast-image'
const YourImage = () =>
<FastImage
style={styles.image}
source={{
uri: 'https://unsplash.it/400/400?image=1',
headers:{ Authorization: 'someAuthToken' },
priority: FastImage.priority.normal,
}}
resizeMode={FastImage.resizeMode.contain}
/>
Properties
source?: object
Source for the remote image to load.
source.uri?: string
Remote url to load the image from. e.g. 'https://facebook.github.io/react/img/logo_og.png'
.
source.headers?: object
Headers to load the image with. e.g. { Authorization: 'someAuthToken' }
.
source.priority?: enum
FastImage.priority.low
- Low PriorityFastImage.priority.normal
(Default) - Normal PriorityFastImage.priority.high
- High Priority
resizeMode?: enum
FastImage.resizeMode.contain
- Scale the image uniformly (maintain the image's aspect ratio) so that both dimensions (width and height) of the image will be equal to or less than the corresponding dimension of the view (minus padding).FastImage.resizeMode.cover
(Default) - Scale the image uniformly (maintain the image's aspect ratio) so that both dimensions (width and height) of the image will be equal to or larger than the corresponding dimension of the view (minus padding).FastImage.resizeMode.stretch
- Scale width and height independently, This may change the aspect ratio of the src.FastImage.resizeMode.center
- Do not scale the image, keep centered.
onLoadStart?: () => void
Called when the image starts to load.
onProgress?: (event) => void
Called when the image is loading.
e.g. onProgress={e => console.log(e.nativeEvent.loaded / e.nativeEvent.total)}
onLoad?: () => void
Called on a successful image fetch.
onError?: () => void
Called on an image fetching error.
onLoadEnd?: () => void
Called when the image finishes loading, whether it was successful or an error.
borderRadius: number
A border radius for the image. Can be used to make a circular cropped version of the image.
Static Methods
FastImage.preload: (source[]) => void
Preload images to display later. e.g.
FastImage.preload([
{
uri: 'https://facebook.github.io/react/img/logo_og.png',
headers: { Authorization: 'someAuthToken' },
},
{
uri: 'https://facebook.github.io/react/img/logo_og.png',
headers: { Authorization: 'someAuthToken' },
},
])
Development
# Install SDWebImage submodules.
git submodule update --init --recursive
# Install npm dependencies.
yarn
Developing modules for React Native is currently a mess because the packager does not support symlinks.
Both major package managers, npm@5
and yarn
, do local installations by creating symlinks.
Unfortunately for now the workaround to update the example is to run:
# In the repo directory pack the module:
npm pack
# This makes a tarball like:
# react-native-fast-image-1.0.0.tgz
# Move into the example:
cd example
# Install the tarball:
npm install ../react-native-fast-image-1.0.0.tgz
To update while developing you can re-pack and reinstall the tarball.
Hopefully metro will add support for symlinks soon.
Supported React Native Versions
This project only aims to support the latest version of React Native.
This simplifies the development and the testing of the project.
If you require new features or bug fixes for older versions you can fork this project.
Credits
The idea for this modules came from vovkasm's react-native-web-image package. It also uses Glide and SDWebImage, but didn't have some features I needed (priority, headers).
Licenses
- FastImage [MIT]
- SDWebImage (included) [MIT]
- Glide (included via gradle) [Apache 2.0 License]