santosh-kumar-kaushal/react-native-as-an-android-lib

Adding a react-native library dependency to an Android app

The repo is archived!

This is a spike UNMAINTAINED

Objective

The objective is to add react-native dependencies to a vanilla Android app. This goal being to use react-native without commiting entirely to the platform.

Benefits are :

• Keep an exiting app setup, i.e. do not plainly move and commit to the platform.
• Use the power of react-native :
• To handover certain apsect of an app to non-android developerse (sign in / up for instance)
• To prototype quickly.

Approach

Reac-native is a plaform and one may not want to move an entire app to it.

Good reasons are :

• It has impact on the file structure, and on the IDE integration
• The plaform is still immature

However, react-native is promissing and can already used to prototype or could even be used to integrate modules.

Pitfals

Min SDK

it has to be >= 16.

Depdency

React-native require your applicattion to implement the ReactApplication interface to run. This means that the app needs to add a dependency to 'com.facebook.react:react-native`.

The latter is a npm dependency so to work well outside of a react naive project (a project initialized with react-nmatie init and containing a folder node_modules) it has to be deployed to a maven repository.

Including this has an overhead in size :

• 1.5M normal.apk
• 8.5M react_native.apk
• 7.9M react_native.apk proguarded

There is not much we can do about that since about 6M comes from react-native ndk libraries (compiled for arm64-v8a, armeabi, armeabi-v7a x86 , x86_64).

It has also an overhead in method count (w/o running proguard) :

• 21113 normal.apk, cf dex count
• 36622 react_native.apk, cf dex count
• 22268 react_native.apk proguarded, cf dex count

Packaging

A little customization has been required to package the aar library (but not too bad).

apply plugin: "com.android.library"

project.ext.react = [
        bundleInDebug   : true,
        jsBundleDirDebug: "$buildDir/intermediates/bundles/debug/assets",
        jsBundleDirRelease: "$buildDir/intermediates/bundles/release/assets"
]

Alternative integrations

If the footpint is a concernt, an other alternative would be to constraint react-native to protoyping and in a specific flavor and therefore has no impact on production app.

Open questions

• crash reporting ?