Linking Libraries

Linking Libraries

Project with Native Code Required

This page only applies to projects made with react-native init or to those made with Create React Native App which have since ejected. For more information about ejecting, please see the guide on the Create React Native App repository.

Not every app uses all the native capabilities, and including the code to support all those features would impact the binary size... But we still want to make it easy to add these features whenever you need them.

With that in mind we exposed many of these features as independent static libraries.

For most of the libs it will be as simple as dragging two files, sometimes a third step will be necessary, but no more than that.

All the libraries we ship with React Native live on the Libraries folder in the root of the repository. Some of them are pure JavaScript, and you only need to require it. Other libraries also rely on some native code, in that case you'll have to add these files to your app, otherwise the app will throw an error as soon as you try to use the library.

Here the few steps to link your libraries that contain native code

Automatic linking

Step 1

Install a library with native dependencies:

$ npm install <library-with-native-dependencies> --save

Note: --save or --save-dev flag is very important for this step. React Native will link your libs based on dependencies and devDependencies in your package.json file.

Step 2

Link your native dependencies:

$ react-native link

Done! All libraries with native dependencies should be successfully linked to your iOS/Android project.

Manual linking

Step 1

If the library has native code, there must be a .xcodeproj file inside it's folder. Drag this file to your project on Xcode (usually under the Libraries group on Xcode);

Step 2

Click on your main project file (the one that represents the .xcodeproj) select Build Phases and drag the static library from the Products folder inside the Library you are importing to Link Binary With Libraries

Step 3

Not every library will need this step, what you need to consider is:

Do I need to know the contents of the library at compile time?

What that means is, are you using this library on the native side or only in JavaScript? If you are only using it in JavaScript, you are good to go!

This step is not necessary for libraries that we ship with React Native with the exception of PushNotificationIOS and Linking.

In the case of the PushNotificationIOS for example, you have to call a method on the library from your AppDelegate every time a new push notification is received.

For that we need to know the library's headers. To achieve that you have to go to your project's file, select Build Settings and search for Header Search Paths. There you should include the path to your library (if it has relevant files on subdirectories remember to make it recursive, like React on the example).