Merge pull request #300 from tadeuzagallo/doc-link-libraries

[ReactNative][Docs] Document how to link libraries

Author: tadeuzagallo

docs/Libraries.md

@@ -0,0 +1,67 @@
+---
+id: libraries
+title: Linking Libraries
+layout: docs
+category: Guides
+permalink: docs/linking-libraries.html
+next: debugging
+---
+
+Not every app uses all the native capabilities, and including the code to support
+all those features would impact in the binary size... But we still want to make
+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 simples 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 just 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
+
+### 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 `Libaries` group
+on Xcode);
+
+![](/react-native/img/AddToLibraries.png)
+
+### 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
+insed the Library you are importing to `Link Binary With Libraries`
+
+![](/react-native/img/AddToBuildPhases.png)
+
+### 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 site or just in
+JavaScript? If you are just using it in JavaScript, you are good to go!
+
+
+This step is not necessary for all libraries that we ship we React Native but
+`PushNotificationIOS` and `LinkingIOS`.
+
+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 notifiation 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 you library (if it has relevant
+files on subdirectories remember to make it `recursive`, like `React` on the
+example).
+
+![](/react-native/img/AddToSearchPaths.png)

docs/NativeModulesIOS.md

@@ -4,7 +4,7 @@ title: Native Modules (iOS)
 layout: docs
 category: Guides
 permalink: docs/nativemodulesios.html
-next: debugging
+next: libraries
 ---
 
 Sometimes an app needs access to platform API, and React Native doesn't have a corresponding wrapper yet. Maybe you want to reuse some existing Objective-C or C++ code without having to reimplement it in JavaScript. Or write some high performance, multi-threaded code such as image processing, network stack, database or rendering.