Summary:
We really need a better list view - so here it is!
Main changes from existing `ListView`:
* Items are "virtualized" to limit memory - that is, items outside of the render window are unmounted and their memory is reclaimed. This means that instance state is not preserved when items scroll out of the render window.
* No `DataSource` - just a simple `data` prop of shape `Array<any>`. By default, they are expected to be of the shape `{key: string}` but a custom `rowExtractor` function can be provided for different shapes, e.g. graphql data where you want to map `id` to `key`. Note the underlying `VirtualizedList` is much more flexible.
* Fancy `scrollTo` functionality: `scrollToEnd`, `scrollToIndex`, and `scrollToItem` in addition to the normal `scrollToOffset`.
* Built-in pull to refresh support - set set the `onRefresh` and `refreshing` props.
* Rendering additional rows is usually done with low priority, after any interactions/animations complete, unless we're about to run out of rendered content. This should help apps feel more responsive.
* Component props replace render functions, e.g. `ItemComponent: ReactClass<{item: Item, index: number}>` replaces `renderRow: (...) => React.Element<*>`
* Supports dynamic items automatically by using `onLayout`, or `getItemLayout` can be provided for a perf boost and smoother `scrollToIndex` and scroll bar behavior.
* Visibility callback replaced with more powerful viewability callback and works in vertical and horizontal mode on at least Android and iOS, but probably other platforms as well. Extra power comes from the `viewablePercentThreshold` that lets the client decide when an item should be considered viewable.
Demo:
https://www.facebook.com/groups/576288835853049/permalink/753923058089625/
Reviewed By: yungsters
Differential Revision: D4412469
fbshipit-source-id: e2d891490bf76fe14df49294ecddf78a58adcf23
UIExplorer
The UIExplorer is a sample app that showcases React Native views and modules.
Running this app
Before running the app, make sure you ran:
git clone https://github.com/facebook/react-native.git
cd react-native
npm install
Running on iOS
Mac OS and Xcode are required.
- Open
Examples/UIExplorer/UIExplorer.xcodeprojin Xcode - Hit the Run button
See Running on device if you want to use a physical device.
Running on Android
You'll need to have all the prerequisites (SDK, NDK) for Building React Native installed.
Start an Android emulator (Genymotion is recommended).
cd react-native
./gradlew :Examples:UIExplorer:android:app:installDebug
./packager/packager.sh
Note: Building for the first time can take a while.
Open the UIExplorer app in your emulator.
See Running on Device in case you want to use a physical device.
Running with Buck
Follow the same setup as running with gradle.
Install Buck from here.
Run the following commands from the react-native folder:
./gradlew :ReactAndroid:packageReactNdkLibsForBuck
buck fetch uiexplorer
buck install -r uiexplorer
./packager/packager.sh
Note: The native libs are still built using gradle. Full build with buck is coming soon(tm).
Built from source
Building the app on both iOS and Android means building the React Native framework from source. This way you're running the latest native and JS code the way you see it in your clone of the github repo.
This is different from apps created using react-native init which have a dependency on a specific version of React Native JS and native code, declared in a package.json file (and build.gradle for Android apps).