react-native/ReactAndroid

Building React Native for Android

This guide contains instructions for building the Android code and running the sample apps.

Supported Operating Systems

This setup has only been tested on Mac OS so far.

Prerequisites

Assuming you have the Android SDK installed, run android to open the Android SDK Manager.

Make sure you have the following installed:

• Android SDK version 22 (compileSdkVersion in build.gradle)
• SDK build tools version 22.0.1 (buildToolsVersion in build.gradle)
• Android Support Repository 17 (for Android Support Library)
• Android NDK (download & extraction instructions here)

Point Gradle to your Android SDK: either have $ANDROID_SDK and $ANDROID_NDK defined, or create a local.properties file in the root of your react-native checkout with the following contents:

sdk.dir=absolute_path_to_android_sdk
ndk.dir=absolute_path_to_android_ndk

Example:

sdk.dir=/Users/your_unix_name/android-sdk-macosx
ndk.dir=/Users/your_unix_name/android-ndk/android-ndk-r10c

Run npm install

This is needed to fetch the dependencies for the packager.

cd react-native
npm install

Building from the command line

To build the framework code:

cd react-native
./gradlew :ReactAndroid:assembleDebug

To install a snapshot version of the framework code in your local Maven repo:

./gradlew :ReactAndroid:installArchives

Running the examples

To run the Sample app:

cd react-native
./gradlew :Examples:SampleApp:android:app:installDebug
# Start the packager in a separate shell:
# Make sure you ran npm install
./packager/packager.sh
# Open SampleApp in your emulator, Menu button -> Reload JS should work

You can run any other sample app the same way, e.g.:

./gradlew :Examples:Movies:android:app:installDebug
./gradlew :Examples:UIExplorer:android:app:installDebug

Building from Android Studio

You'll need to do one additional step until we release the React Native Gradle plugin to Maven central. This is because Android Studio has its own local Maven repo:

mkdir -p /Applications/Android\ Studio.app/Contents/gradle/m2repository/com/facebook/react
cp -r ~/.m2/repository/com/facebook/react/gradleplugin /Applications/Android\ Studio.app/Contents/gradle/m2repository/com/facebook/react/

Now, open Android Studio, click Import Non-Android Studio project and find your react-native repo.

In the configurations dropdown, app should be selected. Click Run.

Installing the React Native .aar in your local Maven repo

In some cases, for example when working on the react-native-cli it's useful to publish a snapshot version of React Native into your local Maven repo. This way, Gradle can pick it up when building projects that have a Maven dependency on React Native.

Run:

cd react-native-android
./gradlew :ReactAndroid:installArchives

Troubleshooting

Gradle build fails in ndk-build. See the section about local.properties file above.

Gradle build fails "Could not find any version that matches com.facebook.react:gradleplugin:...". See the section about the React Native Gradle plugin above.

Packager throws an error saying a module is not found. Try running npm install in the root of the repo.