chrome.fileSystem

This API is part of the deprecated Chrome Apps platform. Learn more about migrating your app.

Description
Use the chrome.fileSystem API to create, read, navigate, and write to the user's local file system. With this API, Chrome Apps can read and write to a user-selected location. For example, a text editor app can use the API to read and write local documents. All failures are notified via chrome.runtime.lastError.
Permissions
fileSystem
Availability
Foreground only

Summary

Types
AcceptOption
ChooseEntryOptions
ChooseEntryType
RequestFileSystemOptions
Volume
VolumeListChangedEvent
Methods
chooseEntry
getDisplayPath
getVolumeList
getWritableEntry
isRestorable
isWritableEntry
requestFileSystem
restoreEntry
retainEntry
Events
onVolumeListChanged

Types

AcceptOption

Properties

description
string optional
This is the optional text description for this option. If not present, a description will be automatically generated; typically containing an expanded list of valid extensions (e.g. "text/html" may expand to "*.html, *.htm").
extensions
string[] optional
Extensions to accept, e.g. "jpg", "gif", "crx".
mimeTypes
string[] optional
Mime-types to accept, e.g. "image/jpeg" or "audio/*". One of mimeTypes or extensions must contain at least one valid element.

ChooseEntryOptions

Properties

accepts
AcceptOption[] optional
The optional list of accept options for this file opener. Each option will be presented as a unique group to the end-user.
acceptsAllTypes
boolean optional
Whether to accept all file types, in addition to the options specified in the accepts argument. The default is true. If the accepts field is unset or contains no valid entries, this will always be reset to true.
acceptsMultiple
boolean optional
Whether to accept multiple files. This is only supported for openFile and openWritableFile. The callback to chooseEntry will be called with a list of entries if this is set to true. Otherwise it will be called with a single Entry.
suggestedName
string optional
The suggested file name that will be presented to the user as the default name to read or write. This is optional.
type
ChooseEntryType optional
Type of the prompt to show. The default is 'openFile'.

ChooseEntryType

Type

"openFile"

"openWritableFile"

"saveFile"

, or

"openDirectory"

RequestFileSystemOptions

Chrome 44+

Properties

volumeId
string
The ID of the requested volume.
writable
boolean optional
Whether the requested file system should be writable. The default is read-only.

Volume

Chrome 44+

Properties

volumeId
string
writable
boolean

VolumeListChangedEvent

Chrome 44+

Properties

volumes
Volume[]

Methods

chooseEntry


          
          
            chrome.fileSystem.chooseEntry(

        options?:
  ChooseEntryOptions,

        callback:
  function,

      
    )

Ask the user to choose a file or directory.

Parameters

options
ChooseEntryOptions optional
callback
function
The callback parameter looks like: (entry?: Entry, fileEntries?: FileEntry[]) => void
- entry
  Entry optional
- fileEntries
  FileEntry[] optional

getDisplayPath


          
          
            chrome.fileSystem.getDisplayPath(

        entry:
  Entry,

        callback:
  function,

      
    )

Get the display path of an Entry object. The display path is based on the full path of the file or directory on the local file system, but may be made more readable for display purposes.

Parameters

entry
Entry
callback
function
The callback parameter looks like: (displayPath: string) => void
- displayPath
  string

getVolumeList


          
          
            chrome.fileSystem.getVolumeList(

        callback:
  function,

      
    )

Chrome 44+

Returns a list of volumes available for requestFileSystem(). The "fileSystem": {"requestFileSystem"} manifest permission is required. Available to kiosk apps running in the kiosk session only. In case of an error, volumes will be undefined, and chrome.runtime.lastError will be set.

Parameters

callback
function
The callback parameter looks like: (volumes?: Volume[]) => void
- volumes
  Volume[] optional

getWritableEntry


          
          
            chrome.fileSystem.getWritableEntry(

        entry:
  Entry,

        callback:
  function,

      
    )

Get a writable Entry from another Entry. This call will fail with a runtime error if the application does not have the 'write' permission under 'fileSystem'. If entry is a DirectoryEntry, this call will fail if the application does not have the 'directory' permission under 'fileSystem'.

Parameters

entry
Entry
callback
function
The callback parameter looks like: (entry: Entry) => void
- entry
  Entry

isRestorable


          
          
            chrome.fileSystem.isRestorable(

        id:
  string,

        callback:
  function,

      
    )

Returns whether the app has permission to restore the entry with the given id.

Parameters

id
string
callback
function
The callback parameter looks like: (isRestorable: boolean) => void
- isRestorable
  boolean

isWritableEntry


          
          
            chrome.fileSystem.isWritableEntry(

        entry:
  Entry,

        callback:
  function,

      
    )

Gets whether this Entry is writable or not.

Parameters

entry
Entry
callback
function
The callback parameter looks like: (isWritable: boolean) => void
- isWritable
  boolean

requestFileSystem


          
          
            chrome.fileSystem.requestFileSystem(

        options:
  RequestFileSystemOptions,

        callback:
  function,

      
    )

Chrome 44+

Requests access to a file system for a volume represented by options.volumeId. If options.writable is set to true, then the file system will be writable. Otherwise, it will be read-only. The writable option requires the "fileSystem": {"write"} permission in the manifest. Available to kiosk apps running in kiosk session only. For manual-launch kiosk mode, a confirmation dialog will be shown on top of the active app window. In case of an error, fileSystem will be undefined, and chrome.runtime.lastError will be set.

Parameters

options
RequestFileSystemOptions
callback
function
The callback parameter looks like: (fileSystem?: FileSystem) => void
- fileSystem
  FileSystem optional

restoreEntry


          
          
            chrome.fileSystem.restoreEntry(

        id:
  string,

        callback:
  function,

      
    )

Returns the file entry with the given id if it can be restored. This call will fail with a runtime error otherwise.

Parameters

id
string
callback
function
The callback parameter looks like: (entry: Entry) => void
- entry
  Entry

retainEntry


          
          
            chrome.fileSystem.retainEntry(

        entry:
  Entry,

      
    )

Returns an id that can be passed to restoreEntry to regain access to a given file entry. Only the 500 most recently used entries are retained, where calls to retainEntry and restoreEntry count as use. If the app has the 'retainEntries' permission under 'fileSystem', entries are retained indefinitely. Otherwise, entries are retained only while the app is running and across restarts.

Parameters

entry
Entry

Returns

string

Events

onVolumeListChanged


          
          
            chrome.fileSystem.onVolumeListChanged.addListener(

        callback:
  function,

      
    )

Chrome 44+

Called when a list of available volumes is changed.

Parameters

callback
function
The callback parameter looks like: (event: VolumeListChangedEvent) => void
- event
  VolumeListChangedEvent