react-native-fs

Native filesystem access for react-native

Usage (iOS)

First you need to install react-native-fs:

npm install react-native-fs --save

In XCode, in the project navigator, right click Libraries ➜ Add Files to [your project's name] Go to node_modules ➜ react-native-fs and add the .xcodeproj file

In XCode, in the project navigator, select your project. Add the lib*.a from the RNFS project to your project's Build Phases ➜ Link Binary With Libraries Click .xcodeproj file you added before in the project navigator and go the Build Settings tab. Make sure 'All' is toggled on (instead of 'Basic'). Look for Header Search Paths and make sure it contains both (SRCROOT)/../react-native/React and (SRCROOT)/../../React - mark both as recursive.

Run your project (Cmd+R)

Usage (Android)

Android support is currently limited to only the DocumentDirectory. This maps to the app's files directory.

Make alterations to the following files:

• android/settings.gradle

...
include ':react-native-fs'
project(':react-native-fs').projectDir = new File(settingsDir, '../node_modules/react-native-fs/android')

• android/app/build.gradle

...
dependencies {
    ...
    compile project(':react-native-fs')
}

• register module (in MainActivity.java)

import com.rnfs.RNFSPackage;  // <--- import

public class MainActivity extends Activity implements DefaultHardwareBackBtnHandler {

  ......

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    mReactRootView = new ReactRootView(this);

    mReactInstanceManager = ReactInstanceManager.builder()
      .setApplication(getApplication())
      .setBundleAssetName("index.android.bundle")
      .setJSMainModuleName("index.android")
      .addPackage(new MainReactPackage())
      .addPackage(new RNFSPackage())      // <------- add package
      .setUseDeveloperSupport(BuildConfig.DEBUG)
      .setInitialLifecycleState(LifecycleState.RESUMED)
      .build();

    mReactRootView.startReactApplication(mReactInstanceManager, "ExampleRN", null);

    setContentView(mReactRootView);
  }

  ......

}

Examples

Basic

// require the module
var RNFS = require('react-native-fs');

// get a list of files and directories in the main bundle
RNFS.readDir(RNFS.MainBundlePath)
  .then((result) => {
    console.log('GOT RESULT', result);

    // stat the first file
    return Promise.all([RNFS.stat(result[0].path), result[0].path]);
  })
  .then((statResult) => {
    if (statResult[0].isFile()) {
      // if we have a file, read it
      return RNFS.readFile(statResult[1], 'utf8');
    }

    return 'no file';
  })
  .then((contents) => {
    // log the file contents
    console.log(contents);
  })
  .catch((err) => {
    console.log(err.message, err.code);
  });

File creation

// require the module
var RNFS = require('react-native-fs');

// create a path you want to write to
var path = RNFS.DocumentDirectoryPath + '/test.txt';

// write the file
RNFS.writeFile(path, 'Lorem ipsum dolor sit amet', 'utf8')
  .then((success) => {
    console.log('FILE WRITTEN!');
  })
  .catch((err) => {
    console.log(err.message);
  });

File deletion

// create a path you want to delete
var path = RNFS.DocumentDirectoryPath + '/test.txt';

return RNFS.unlink(path)
  // spread is a method offered by bluebird to allow for more than a
  // single return value of a promise. If you use `then`, you will receive
  // the values inside of an array
  .spread((success, path) => {
  console.log('FILE DELETED', success, path);
  })
  // `unlink` will throw an error, if the item to unlink does not exist
  .catch((err) => {
    console.log(err.message);
  });

API

Constants

The following constants are available on the RNFS export:

MainBundlePath (String) The absolute path to the main bundle directory
CachesDirectoryPath (String) The absolute path to the caches directory
DocumentDirectoryPath (String) The absolute path to the document directory

promise readDir(path)

Reads the contents of path. This must be an absolute path. Use the above path constants to form a usable file path.

The returned promise resolves with an array of objects with the following properties:

name (String) - The name of the item
path (String) - The absolute path to the item
size (Number) - Size in bytes

promise readdir(path)

Node.js style version of readDir that returns only the names. Note the lowercase d.

promise stat(path)

Stats an item at path.
The promise resolves with an object with the following properties:

ctime (Date) - The creation date of the item
mtime (Date) - The modification date of the item
size (Number) - The size of the item in bytes
isFile (Function) - Returns true when the item is a file
isDirectory (Function) - Returns true when the item is a directory

promise readFile(path [, encoding])

Reads the file at path and return contents. encoding can be one of utf8 (default), ascii, base64. Use base64 for reading binary files.

Note: you will take quite a performance hit if you are reading big files

promise writeFile(filepath, contents [, encoding, options])

Write the contents to filepath. encoding can be one of utf8 (default), ascii, base64. options optionally takes an object specifying the file's properties, like mode etc.

The promise resolves with a boolean.

promise unlink(filepath)

Unlinks the item at filepath. If the item does not exist, an error will be thrown.

The promise resolves with an array, which contains a boolean and the path that has been unlinked. Tip: use spread to receive the two arguments instead of a single array in your handler.

Also recursively deletes directories (works like Linux rm -rf).

promise mkdir(filepath [, excludeFromBackup])

Create a directory at filepath. Automatically creates parents and does not throw if already exists (works like Linux mkdir -p).

IOS only: If excludeFromBackup is true, then NSURLIsExcludedFromBackupKey attribute will be set. Apple will reject apps for storing offline cache data that does not have this attribute.

promise downloadFile(url, filepath[, progressCallback])

Download file from url to filepath. Will overwrite any previously existing file.

If progressCallback is provided, it will be invoked continuously and passed a single argument with the following properties:

statusCode (Number) - The response code from the server
contentLength (Number) - The total size in bytes of the download resource
bytesWritten (Number) - The number of bytes written to the file so far

Percentage can be computed easily by dividing bytesWritten by contentLength.