react-native-file-access

Filesystem access for React Native. Supports saving network requests directly to the filesystem. Supports Android scoped storage, a requirement when targeting API 30 or higher.

Installation

npm install react-native-file-access
cd ios && pod install

Apple restricts usage of certain privacy sensitive API calls. If you do not use disk space measurements or file timestamps, define the following variable in your Podfile to exclude restricted API calls. More details.

$RNFANoPrivacyAPI = true

If the app does not use autolinking, continue to the manual install instructions in the wiki.

Compatibility

React Native	react-native-file-access
<= 0.64	1.x.x
0.65+, old arch	2.x.x, 3.x.x
0.71+, new arch	3.x.x
0.77+, new arch	4.x.x

Usage

import { Dirs, FileSystem } from 'react-native-file-access';

// ...

const text = await FileSystem.readFile(Dirs.CacheDir + '/test.txt');

Directory constants.

• Dirs.CacheDir
• Dirs.DatabaseDir (Android only)
• Dirs.DocumentDir
• Dirs.LibraryDir (iOS & MacOS only)
• Dirs.MainBundleDir
• Dirs.SDCardDir (Android only)
• Prefer FileSystem.cpExternal() when possible.

Functions.

FileSystem.appendFile(path: string, data: string, encoding?: 'utf8' | 'base64'): Promise<void>

• Append content to a file.
• Default encoding of data is assumed utf8.

FileSystem.concatFiles(source: string, target: string): Promise<number>

• Append a file to another file. Returns number of bytes written.

FileSystem.cp(source: string, target: string, onProgress?: (bytesCopied: number, contentLength: number, done: boolean) => void): Promise<void>

• Copy a file.

FileSystem.cpAsset(asset: string, target: string, type?: 'asset' | 'resource'): Promise<void>

• Copy a bundled asset file.
• Default type is asset. Prefer this when possible.
• resource uses the Android res/ folder, and inherits the associated naming restrictions.

FileSystem.cpExternal(source: string, targetName: string, dir: 'audio' | 'downloads' | 'images' | 'video'): Promise<void>

• Copy a file to an externally controlled location.
• On Android API level < 29, may require permission WRITE_EXTERNAL_STORAGE.
• On iOS, consider using Dirs.DocumentDir with UIFileSharingEnabled and LSSupportsOpeningDocumentsInPlace enabled.

FileSystem.df(): Promise<{ internal_free: number, internal_total: number, external_free?: number, external_total?: number }>

• Check device available space.

FileSystem.exists(path: string): Promise<boolean>

• Check if a path exists.

FileSystem.fetch(
  resource: string,
  init: { body?: string, headers?: { [key: string]: string }, method?: string, network?: 'any' | 'unmetered', path?: string },
  onProgress?: (bytesRead: number, contentLength: number, done: boolean) => void
): Promise<FetchResult>

type FetchResult = {
  getHeader: (header: string) => string | undefined;
  headers: { [key: string]: string };
  ok: boolean;
  redirected: boolean;
  status: number;
  statusText: string;
  url: string;
}

• Save a network request to a file.
• resource - URL to fetch.
• init.path - Optional filesystem location to save the response.
• init.network - Optional restriction on network type. Specifying unmetered will reject the request if unmetered connections (most likely WiFi) are unavailable.
• onProgress - Optional callback to listen to download progress. Events are rate limited, so do not rely on done becoming true. contentLength is only accurate if the server sends the correct headers.

FileSystem.fetchManaged(
  resource: string,
  init: { body?: string, headers?: { [key: string]: string }, method?: string, network?: 'any' | 'unmetered', path?: string },
  onProgress?: (bytesRead: number, contentLength: number, done: boolean) => void
): ManagedFetchResult

type ManagedFetchResult = {
  cancel: () => Promise<void>;
  result: Promise<FetchResult>;
}

• Save a network request to a file.
• Similar to fetch(), with the option to cancel before completion.

FileSystem.getAppGroupDir(groupName: string): Promise<string>

• Get the directory for your app group (iOS & MacOS only).
• App groups are used on iOS/MacOS for storing content, which is shared between apps.
• This is e.g. useful for sharing data between your iOS/MacOS app and a widget or a watch app.

FileSystem.hardlink(source: string, target: string): Promise<void>

• Create a hard link at target pointing to source.
• Note: On Android, creating hardlinks requires root access.

FileSystem.hash(path: string, algorithm: 'MD5' | 'SHA-1' | 'SHA-224' | 'SHA-256' | 'SHA-384' | 'SHA-512'): Promise<string>

• Hash the file content.

FileSystem.isDir(path: string): Promise<boolean>

• Check if a path is a directory.

FileSystem.ls(path: string): Promise<string[]>

• List files in a directory.

FileSystem.mkdir(path: string): Promise<string>

• Make a new directory.
• Returns path of created directory.

FileSystem.mv(source: string, target: string): Promise<void>

• Move a file.

FileSystem.readFile(path: string, encoding?: 'utf8' | 'base64'): Promise<string>

• Read the content of a file.
• Default encoding of returned string is utf8.

FileSystem.readFileChunk(path: string, offset: number, length: number, encoding?: 'utf8' | 'base64'): Promise<string>

• Read a chunk of the content of a file, starting from byte at offset, reading for length bytes.
• Default encoding of returned string is utf8.

FileSystem.stat(path: string): Promise<FileStat>

type FileStat = {
  filename: string;
  lastModified: number;
  path: string;
  size: number;
  type: 'directory' | 'file';
}

• Read file metadata.

FileSystem.statDir(path: string): Promise<FileStat[]>

• Read metadata of all files in a directory.

FileSystem.symlink(source: string, target: string): Promise<void>

• Create a symbolic link at target pointing to source.

FileSystem.unlink(path: string): Promise<void>

• Delete a file.

FileSystem.unzip(source: string, target: string): Promise<void>

• Extract a zip archive.

FileSystem.writeFile(path: string, data: string, encoding?: 'utf8' | 'base64'): Promise<void>

• Write content to a file.
• Default encoding of data is assumed utf8.

Utility functions.

Util.basename(path: string, separator?: string): string

• Get the file/folder name from the end of the path.
• Default path separator is /.

Util.dirname(path: string, separator?: string): string

• Get the path containing the file/folder.
• Default path separator is /.

Util.extname(path: string, separator?: string): string

• Get the file extension.
• Default path separator is /.

Scoped storage.

For simple usage, use FileSystem.cpExternal() to submit files to general scoped storage categories.

Most functions in this library work with content:// Android resource uris. To gain access to a resource uri, currently use a library such as react-native-document-picker or react-native-scoped-storage. Eventually this library will incorporate file/folder selector functionality (pull requests welcome).

Note: - When generating a scoped storage resource uri, use the helper AndroidScoped.appendPath(dir, 'data.txt'), not dir + '/data.txt'. - Android may change the name of created files/folders.

AndroidScoped.appendPath(basePath: string, segment: string): string

• Append a path segment to an Android scoped storage content uri.

Testing

For ease of testing, this library contains a mock implementation: jest/react-native-file-access.ts.

Install the mock by adding the following to the jest setup file.

import { mockRnfaModule } from 'react-native-file-access/jest/mock';

jest.mock('react-native-file-access', () => mockRnfaModule);

This may require editing the configured transformIgnorePatterns.

// (Optional) clear mock state between tests:
import { FileSystem } from 'react-native-file-access/jest/mock';

beforeEach(() => {
  FileSystem.filesystem.clear();
});

Alternatively, if modifications are required, copy the mock into the __mocks__ folder, and edit as needed.

Alternatives

This library aims to be a modern implementation of filesystem api, using Kotlin/Swift and latest best practices. For a more established library, consider:

• expo-file-system
• Well supported, a good option if already using Expo.
• react-native-blob-util
• Often a dependency of other libraries.
• Forked from, and compatible with, the popular but deprecated rn-fetch-blob.
• react-native-fs
• Large feature set.
• Low maintenance, aging codebase.

For more greater control over network requests, consider react-native-blob-courier.

Contributing

See the contributing guide to learn how to contribute to the repository and the development workflow.

License

MIT