@bam.tech/react-native-fast-image
v1.3.5
Published
🚩 FastImage, performant React Native image component.
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FastImage
🚩 FastImage, performant React Native image component.
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
- [x] Aggressively cache images.
- [x] Add authorization headers.
- [x] Prioritize images.
- [x] Preload images.
- [x] GIF support.
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
(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 less than the corresponding dimension of the view (minus padding).FastImage.resizeMode.cover
- 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.
children
FastImage
does not currently support children.
Absolute positioning can be used as an alternative.
This is because FastImage
supplies a android.widget.imageview
and not a android.view.viewgroup
.
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
To update the example project modules you will need to run:
npm install
The npm usage is because
yarn will cache locally installed packages and not update them
if the version does not change. yarn also doesn't respect .npmignore
when doing local installs.
To update while developing you can use:
cd example
npm install ../
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]