react-native/docs/GettingStarted.md

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Welcome to React Native! This page will help you install React Native on your system, so that you can build apps with it right away. If you already have React Native installed, you can skip ahead to the Tutorial.

The instructions are a bit different depending on your development operating system, and whether you want to start developing for iOS or Android. If you want to develop for both iOS and Android, that's fine - you just have to pick one to start with, since the setup is a bit different.

Mobile OS: iOS Android Development OS: Mac Linux Windows

Unsupported

Unfortunately, Apple only lets you develop for iOS on a Mac. If you want to build an iOS app but you don't have a Mac yet, you can try starting with the Android instructions instead.

Installing Dependencies

You will need Node.js, Watchman, the React Native command line interface, and Xcode.

You will need Node.js, Watchman, the React Native command line interface, and Android Studio.

Node, Watchman

We recommend installing Node and Watchman using Homebrew. Run the following commands in a Terminal after installing Homebrew:

brew install node
brew install watchman

Watchman is a tool by Facebook for watching changes in the filesystem. It is highly recommended you install it for better performance.

The React Native CLI

Node.js comes with npm, which lets you install the React Native command line interface. Run the following command in a Terminal:

npm install -g react-native-cli

If you get a permission error, try using sudo: sudo npm install -g react-native-cli.

If you get an error like Cannot find module 'npmlog', try installing npm directly: curl -0 -L http://npmjs.org/install.sh | sudo sh.

Xcode

The easiest way to install Xcode is via the Mac App Store. Installing Xcode will also install the iOS Simulator and all the necessary tools to build your iOS app.

Android Development Environment

Setting up your development environment can be somewhat tedious if you're new to Android development. If you're already familiar with Android development, there are a few things you may need to configure. In either case, please make sure to carefully follow the next few steps.

1. Install Android Studio

Download and install Android Studio.

2. Confirm the Android SDK is installed

Android Studio installs Android 7.0 (Nougat) by default. You can confirm that the SDK was installed by clicking on "Configure" in the last screen in the Android Studio Setup Wizard, or by opening "Preferences" from the Android Studio menu, then choosing Appearance and Behavior → System Settings → Android SDK.

Select "SDK Platforms" from within the SDK Manager and you should see a blue checkmark next to "Android 7.0 (Nougat)". In case it is not, click on the checkbox and then "Apply".

If you wish to support older versions of Android, you can install additional Android SDKs from this screen.

3. Set up paths

The React Native command line interface requires the ANDROID_HOME environment variable to be set up. You can configure it in a Terminal using the following command:

export ANDROID_HOME=~/Library/Android/sdk

To avoid doing this every time you open a new terminal, add the following lines to your ~/.bashrc or equivalent config file:

export ANDROID_HOME=~/Library/Android/sdk
export PATH=${PATH}:${ANDROID_HOME}/tools

The second line will add the android tool to your path, which will come in handy in the next step.

Please make sure you export the correct path for ANDROID_HOME if you did not install the Android SDK using Android Studio. If you install the Android SDK using Homebrew, it will be located at /usr/local/opt/android-sdk.

4. Set up your Android Virtual Device

Android Studio should have set up an Android Virtual Device for you during installation, but it is very common to run into an issue where Android Studio fails to install the AVD.

To see the list of available AVDs, launch the "AVD Manager" from within Android Studio or run the following command in a Terminal:

android avd

You may follow the Android Studio User Guide to create a new AVD if needed.

If you see "No system images installed for this target." under CPU/ABI, go back to your "SDK Manager" and click on "Show Package Details" under "SDK Platforms". You will then be able to install any missing system images, such as "Google APIs Intel Atom (x86)".

Installing Dependencies

You will need Node.js, the React Native command line interface, and Android Studio.

Node

Follow the installation instructions for your Linux distribution to install Node.js 4 or newer.

You will need Node.js, the React Native command line interface, and Android Studio.

Node

We recommend installing Node.js and Python2 via Chocolatey, a popular package manager for Windows. Open a Command Prompt as Administrator, then run:

choco install nodejs.install
choco install python2

You can find additional installation options on Node.js's Downloads page.

The React Native CLI

Node comes with npm, which lets you install the React Native command line interface.

npm install -g react-native-cli

Android Development Environment

Setting up your development environment can be somewhat tedious if you're new to Android development. If you're already familiar with Android development, there are a few things you may need to configure. In either case, please make sure to carefully follow the next few steps.

1. Install Android Studio

Download and install Android Studio.

2. Confirm the Android SDK is installed

Android Studio installs Android 7.0 (Nougat) by default. You can confirm that the SDK was installed by clicking on "Configure" in the last screen in the Android Studio Setup Wizard, or by opening "Preferences" from the Android Studio menu, then choosing Appearance and Behavior → System Settings → Android SDK.

Select "SDK Platforms" from within the SDK Manager and you should see a blue checkmark next to "Android 7.0 (Nougat)". In case it is not, click on the checkbox and then "Apply".

If you wish to support older versions of Android, you can install additional Android SDKs from this screen.

3. Set up paths

The React Native command line interface requires the ANDROID_HOME environment variable to be set up.

Create or edit your ~/.bashrc file and add the following lines:

export ANDROID_HOME=~/Android/Sdk
export PATH=${PATH}:${ANDROID_HOME}/tools
export PATH=${PATH}:${ANDROID_HOME}/platform_tools

The second line will add the android tool to your path, which will come in handy in the next step. The third line will add the adb tool to your path, which is used to communicate with your Android device / emulator.

Please make sure you export the correct path for ANDROID_HOME if you did not install the Android SDK using Android Studio.

Go to Control Panel → System and Security → System → Change settings → Advanced System Settings → Environment variables → New, then enter the path to your Android SDK.

Please make sure you use the correct path for ANDROID_HOME if you did not install the Android SDK using Android Studio.

Restart the Command Prompt to apply the new environment variable.

4. Set up your Android Virtual Device

Android Studio should have set up an Android Virtual Device for you during installation, but it is very common to run into an issue where Android Studio fails to install the AVD.

To see the list of available AVDs, launch the "AVD Manager" from within Android Studio or run the following command in a terminal:

android avd

You may follow the Android Studio User Guide to create a new AVD if needed.

If you see "No system images installed for this target." under CPU/ABI, go back to your "SDK Manager" and click on "Show Package Details" under "SDK Platforms". You will then be able to install any missing system images, such as "Google APIs Intel Atom (x86)".

Watchman (optional)

Follow the Watchman installation guide to compile and install Watchman from source.

Watchman is a tool by Facebook for watching changes in the filesystem. It is highly recommended you install it for better performance, but it's alright to skip this if you find the process to be tedious.

Testing your React Native Installation

Use the React Native command line interface to generate a new React Native project called "AwesomeProject", then run react-native run-ios inside the newly created folder.

react-native init AwesomeProject
cd AwesomeProject
react-native run-ios

You should see your new app running in the iOS Simulator shortly.

react-native run-ios is just one way to run your app. You can also run it directly from within Xcode or Nuclide.

Use the React Native command line interface to generate a new React Native project called "AwesomeProject", then run react-native run-android inside the newly created folder.

react-native init AwesomeProject
cd AwesomeProject
react-native run-android

If everything is set up correctly, you should see your new app running in your Android emulator shortly. react-native run-android is just one way to run your app - you can also run it directly from within Android Studio or Nuclide.

Modifying your app

Now that you have successfully run the app, let's modify it.

• Open index.ios.js in your text editor of choice and edit some lines.
• Hit Command⌘ + R in your iOS Simulator to reload the app and see your change!

• Open index.android.js in your text editor of choice and edit some lines.
• Press the R key twice or select Reload from the Developer Menu to see your change!

That's it!

Congratulations! You've successfully run and modified your first React Native app.

Testing your React Native Installation

Use the React Native command line interface to generate a new React Native project called "AwesomeProject", then run react-native run-android inside the newly created folder.

react-native init AwesomeProject
cd AwesomeProject
react-native run-android

If everything is set up correctly, you should see your new app running in your Android emulator shortly.

A common issue is that the packager is not started automatically when you run react-native run-android. You can start it manually using react-native start.

If you hit a ERROR Watcher took too long to load on Windows, try increasing the timeout in this file (under your node_modules/react-native/).

Modifying your app

Now that you have successfully run the app, let's modify it.

• Open index.android.js in your text editor of choice and edit some lines.
• Press the R key twice or select Reload from the Developer Menu to see your change!

That's it!

Congratulations! You've successfully run and modified a React Native app.

Now What?

• If you want to add this new React Native code to an existing application, check out the Integration guide.

• If you can't get this to work, see the Troubleshooting page.

• If you're curious to learn more about React Native, continue on to the Tutorial.