Expo FileSystem

DownloadResumable

Type: Class extends FileSystemCancellableNetworkTask<DownloadProgressData>

DownloadResumable Methods

FileSystemCancellableNetworkTask

FileSystemCancellableNetworkTask Methods

UploadTask

Type: Class extends FileSystemCancellableNetworkTask<UploadProgressData>

UploadTask Methods

FileSystem.copyAsync(options)

Create a copy of a file or directory. Directories are recursively copied with all of their contents. It can be also used to copy content shared by other apps to local filesystem.

Returns

• Promise<void>

FileSystem.createDownloadResumable(uri, fileUri, options, callback, resumeData)

Create a DownloadResumable object which can start, pause, and resume a download of contents at a remote URI to a file in the app's file system.

Note: You need to call downloadAsync(), on a DownloadResumable instance to initiate the download. The DownloadResumable object has a callback that provides download progress updates. Downloads can be resumed across app restarts by using AsyncStorage to store the DownloadResumable.savable() object for later retrieval. The savable object contains the arguments required to initialize a new DownloadResumable object to resume the download after an app restart. The directory for a local file uri must exist prior to calling this function.

Returns

• DownloadResumable

FileSystem.createUploadTask(url, fileUri, options, callback)

Returns

• UploadTask

FileSystem.deleteAsync(fileUri, options)

Delete a file or directory. If the URI points to a directory, the directory and all its contents are recursively deleted.

Returns

• Promise<void>

FileSystem.deleteLegacyDocumentDirectoryAndroid()

Returns

• Promise<void>

FileSystem.downloadAsync(uri, fileUri, options)

Download the contents at a remote URI to a file in the app's file system. The directory for a local file uri must exist prior to calling this function.

Example

FileSystem.downloadAsync(
  'http://techslides.com/demos/sample-videos/small.mp4',
  FileSystem.documentDirectory + 'small.mp4'
)
  .then(({ uri }) => {
    console.log('Finished downloading to ', uri);
  })
  .catch(error => {
    console.error(error);
  });

Returns

• Promise<FileSystemDownloadResult>

Returns a Promise that resolves to a FileSystemDownloadResult object.

FileSystem.getContentUriAsync(fileUri)

Takes a file:// URI and converts it into content URI (content://) so that it can be accessed by other applications outside of Expo.

Example

FileSystem.getContentUriAsync(uri).then(cUri => {
  console.log(cUri);
  IntentLauncher.startActivityAsync('android.intent.action.VIEW', {
    data: cUri,
    flags: 1,
  });
});

Returns

• Promise<string>

Returns a Promise that resolves to a string containing a content:// URI pointing to the file. The URI is the same as the fileUri input parameter but in a different format.

FileSystem.getFreeDiskStorageAsync()

Gets the available internal disk storage size, in bytes. This returns the free space on the data partition that hosts all of the internal storage for all apps on the device.

Returns

• Promise<number>

Returns a Promise that resolves to the number of bytes available on the internal disk, or JavaScript's MAX_SAFE_INTEGER if the capacity is greater than 2⁵³ - 1 bytes.

FileSystem.getInfoAsync(fileUri, options)

Get metadata information about a file, directory or external content/asset.

Returns

• Promise<FileInfo>

A Promise that resolves to a FileInfo object. If no item exists at this URI, the returned Promise resolves to FileInfo object in form of { exists: false, isDirectory: false }.

FileSystem.getTotalDiskCapacityAsync()

Gets total internal disk storage size, in bytes. This is the total capacity of the data partition that hosts all the internal storage for all apps on the device.

Returns

• Promise<number>

Returns a Promise that resolves to a number that specifies the total internal disk storage capacity in bytes, or JavaScript's MAX_SAFE_INTEGER if the capacity is greater than 2⁵³ - 1 bytes.

FileSystem.makeDirectoryAsync(fileUri, options)

Create a new empty directory.

Returns

• Promise<void>

FileSystem.moveAsync(options)

Move a file or directory to a new location.

Returns

• Promise<void>

FileSystem.readAsStringAsync(fileUri, options)

Read the entire contents of a file as a string. Binary will be returned in raw format, you will need to append data:image/png;base64, to use it as Base64.

Returns

• Promise<string>

A Promise that resolves to a string containing the entire contents of the file.

FileSystem.readDirectoryAsync(fileUri)

Enumerate the contents of a directory.

Returns

• Promise<string[]>

A Promise that resolves to an array of strings, each containing the name of a file or directory contained in the directory at fileUri.

FileSystem.uploadAsync(url, fileUri, options)

Upload the contents of the file pointed by fileUri to the remote url.

Example

Client

import * as FileSystem from 'expo-file-system';

try {
  const response = await FileSystem.uploadAsync(`http://192.168.0.1:1234/binary-upload`, fileUri, {
    fieldName: 'file',
    httpMethod: 'PATCH',
    uploadType: FileSystem.FileSystemUploadType.BINARY_CONTENT,
  });
  console.log(JSON.stringify(response, null, 4));
} catch (error) {
  console.log(error);
}

Server

Please refer to the "Server: Handling multipart requests" example - there is code for a simple Node.js server.

Returns

• Promise<FileSystemUploadResult>

Returns a Promise that resolves to FileSystemUploadResult object.

FileSystem.writeAsStringAsync(fileUri, contents, options)

Write the entire contents of a file as a string.

Returns

• Promise<void>