Apache Cordova API Documentation

File System

This plugin implements a File API allowing read/write access to files residing on the device.

This plugin is based on several specs, including : The HTML5 File API http://www.w3.org/TR/FileAPI/

The (now-defunct) Directories and System extensions Latest: http://www.w3.org/TR/2012/WD-file-system-api-20120417/ Although most of the plugin code was written when an earlier spec was current: http://www.w3.org/TR/2011/WD-file-system-api-20110419/

It also implements the FileWriter spec : http://dev.w3.org/2009/dap/file-system/file-writer.html

For usage, please refer to HTML5 Rocks' excellent FileSystem article.

For an overview of other storage options, refer to Cordova's storage guide.

Installation

cordova plugin add org.apache.cordova.file

Supported Platforms

  • Amazon Fire OS
  • Android
  • BlackBerry 10
  • Firefox OS
  • iOS
  • Windows Phone 7 and 8*
  • Windows 8*

* These platforms do not support FileReader.readAsArrayBuffer nor FileWriter.write(blob).

Where to Store Files

As of v1.2.0, URLs to important file-system directories are provided. Each URL is in the form file:///path/to/spot/, and can be converted to a DirectoryEntry using window.resolveLocalFileSystemURL().

  • cordova.file.applicationDirectory - Read-only directory where the application is installed. (iOS, Android, BlackBerry 10)

  • cordova.file.applicationStorageDirectory - Root directory of the application's sandbox; on iOS this location is read-only (but specific subdirectories [like /Documents] are read-write). All data contained within is private to the app. ( iOS, Android, BlackBerry 10)

  • cordova.file.dataDirectory - Persistent and private data storage within the application's sandbox using internal memory (on Android, if you need to use external memory, use .externalDataDirectory). On iOS, this directory is not synced with iCloud (use .syncedDataDirectory). (iOS, Android, BlackBerry 10)

  • cordova.file.cacheDirectory - Directory for cached data files or any files that your app can re-create easily. The OS may delete these files when the device runs low on storage, nevertheless, apps should not rely on the OS to delete files in here. (iOS, Android, BlackBerry 10)

  • cordova.file.externalApplicationStorageDirectory - Application space on external storage. (Android)

  • cordova.file.externalDataDirectory - Where to put app-specific data files on external storage. (Android)

  • cordova.file.externalCacheDirectory - Application cache on external storage. (Android)

  • cordova.file.externalRootDirectory - External storage (SD card) root. (Android, BlackBerry 10)

  • cordova.file.tempDirectory - Temp directory that the OS can clear at will. Do not rely on the OS to clear this directory; your app should always remove files as applicable. (iOS)

  • cordova.file.syncedDataDirectory - Holds app-specific files that should be synced (e.g. to iCloud). (iOS)

  • cordova.file.documentsDirectory - Files private to the app, but that are meaningful to other application (e.g. Office files). (iOS)

  • cordova.file.sharedDirectory - Files globally available to all applications (BlackBerry 10)

File System Layouts

Although technically an implementation detail, it can be very useful to know how the cordova.file.* properties map to physical paths on a real device.

iOS File System Layout

Device Path cordova.file.* iosExtraFileSystems r/w? persistent? OS clears sync private
/var/mobile/Applications/<UUID>/ applicationStorageDirectory - r N/A N/A N/A Yes
   appname.app/ applicationDirectory bundle r N/A N/A N/A Yes
      www/ - - r N/A N/A N/A Yes
   Documents/ documentsDirectory documents r/w Yes No Yes Yes
      NoCloud/ - documents-nosync r/w Yes No No Yes
   Library - library r/w Yes No Yes? Yes
      NoCloud/ dataDirectory library-nosync r/w Yes No No Yes
      Cloud/ syncedDataDirectory - r/w Yes No Yes Yes
      Caches/ cacheDirectory cache r/w Yes* Yes*** No Yes
   tmp/ tempDirectory - r/w No** Yes*** No Yes

* Files persist across app restarts and upgrades, but this directory can be cleared whenever the OS desires. Your app should be able to recreate any content that might be deleted.

** Files may persist across app restarts, but do not rely on this behavior. Files are not guaranteed to persist across updates. Your app should remove files from this directory when it is applicable, as the OS does not guarantee when (or even if) these files are removed.

*** The OS may clear the contents of this directory whenever it feels it is necessary, but do not rely on this. You should clear this directory as appropriate for your application.

Android File System Layout

Device Path cordova.file.* AndroidExtraFileSystems r/w? persistent? OS clears private
file:///android_asset/ applicationDirectory r N/A N/A Yes
/data/data/<app-id>/ applicationStorageDirectory - r/w N/A N/A Yes
   cache cacheDirectory cache r/w Yes Yes* Yes
   files dataDirectory files r/w Yes No Yes
      Documents documents r/w Yes No Yes
<sdcard>/ externalRootDirectory sdcard r/w Yes No No
   Android/data/<app-id>/ externalApplicationStorageDirectory - r/w Yes No No
      cache externalCacheDirectry cache-external r/w Yes No** No
      files externalDataDirectory files-external r/w Yes No No

* The OS may periodically clear this directory, but do not rely on this behavior. Clear the contents of this directory as appropriate for your application. Should a user purge the cache manually, the contents of this directory are removed.

** The OS does not clear this directory automatically; you are responsible for managing the contents yourself. Should the user purge the cache manually, the contents of the directory are removed.

Note: If external storage can't be mounted, the cordova.file.external* properties are null.

BlackBerry 10 File System Layout

Device Path cordova.file.* r/w? persistent? OS clears private
file:///accounts/1000/appdata/<app id>/ applicationStorageDirectory r N/A N/A Yes
   app/native applicationDirectory r N/A N/A Yes
   data/webviews/webfs/temporary/local__0 cacheDirectory r/w No Yes Yes
   data/webviews/webfs/persistent/local__0 dataDirectory r/w Yes No Yes
file:///accounts/1000/removable/sdcard externalRemovableDirectory r/w Yes No No
file:///accounts/1000/shared sharedDirectory r/w Yes No No

Note: When application is deployed to work perimeter, all paths are relative to /accounts/1000-enterprise.

Android Quirks

Android Persistent storage location

There are multiple valid locations to store persistent files on an Android device. See this page for an extensive discussion of the various possibilities.

Previous versions of the plugin would choose the location of the temporary and persistent files on startup, based on whether the device claimed that the SD Card (or equivalent storage partition) was mounted. If the SD Card was mounted, or if a large internal storage partition was available (such as on Nexus devices,) then the persistent files would be stored in the root of that space. This meant that all Cordova apps could see all of the files available on the card.

If the SD card was not available, then previous versions would store data under /data/data/<packageId>, which isolates apps from each other, but may still cause data to be shared between users.

It is now possible to choose whether to store files in the internal file storage location, or using the previous logic, with a preference in your application's config.xml file. To do this, add one of these two lines to config.xml:

<preference name="AndroidPersistentFileLocation" value="Internal" />

<preference name="AndroidPersistentFileLocation" value="Compatibility" />

Without this line, the File plugin will use Compatibility as the default. If a preference tag is present, and is not one of these values, the application will not start.

If your application has previously been shipped to users, using an older (pre- 1.0) version of this plugin, and has stored files in the persistent filesystem, then you should set the preference to Compatibility. Switching the location to "Internal" would mean that existing users who upgrade their application may be unable to access their previously-stored files, depending on their device.

If your application is new, or has never previously stored files in the persistent filesystem, then the Internal setting is generally recommended.

iOS Quirks

  • cordova.file.applicationStorageDirectory is read-only; attempting to store files within the root directory will fail. Use one of the other cordova.file.* properties defined for iOS (only applicationDirectory and applicationStorageDirectory are read-only).
  • FileReader.readAsText(blob, encoding)
    • The encoding parameter is not supported, and UTF-8 encoding is always in effect.

iOS Persistent storage location

There are two valid locations to store persistent files on an iOS device: the Documents directory and the Library directory. Previous versions of the plugin only ever stored persistent files in the Documents directory. This had the side-effect of making all of an application's files visible in iTunes, which was often unintended, especially for applications which handle lots of small files, rather than producing complete documents for export, which is the intended purpose of the directory.

It is now possible to choose whether to store files in the documents or library directory, with a preference in your application's config.xml file. To do this, add one of these two lines to config.xml:

<preference name="iosPersistentFileLocation" value="Library" />

<preference name="iosPersistentFileLocation" value="Compatibility" />

Without this line, the File plugin will use Compatibility as the default. If a preference tag is present, and is not one of these values, the application will not start.

If your application has previously been shipped to users, using an older (pre- 1.0) version of this plugin, and has stored files in the persistent filesystem, then you should set the preference to Compatibility. Switching the location to Library would mean that existing users who upgrade their application would be unable to access their previously-stored files.

If your application is new, or has never previously stored files in the persistent filesystem, then the Library setting is generally recommended.

Firefox OS Quirks

The File System API is not natively supported by Firefox OS and is implemented as a shim on top of indexedDB.

  • Does not fail when removing non-empty directories
  • Does not support metadata for directories
  • Methods copyTo and moveTo do not support directories

The following data paths are supported:

  • applicationDirectory - Uses xhr to get local files that are packaged with the app.
  • dataDirectory - For persistent app-specific data files.
  • cacheDirectory - Cached files that should survive app restarts (Apps should not rely on the OS to delete files in here).

Upgrading Notes

In v1.0.0 of this plugin, the FileEntry and DirectoryEntry structures have changed, to be more in line with the published specification.

Previous (pre-1.0.0) versions of the plugin stored the device-absolute-file-location in the fullPath property of Entry objects. These paths would typically look like

/var/mobile/Applications/<application UUID>/Documents/path/to/file  (iOS)
/storage/emulated/0/path/to/file                                    (Android)

These paths were also returned by the toURL() method of the Entry objects.

With v1.0.0, the fullPath attribute is the path to the file, relative to the root of the HTML filesystem. So, the above paths would now both be represented by a FileEntry object with a fullPath of

/path/to/file

If your application works with device-absolute-paths, and you previously retrieved those paths through the fullPath property of Entry objects, then you should update your code to use entry.toURL() instead.

For backwards compatibility, the resolveLocalFileSystemURL() method will accept a device-absolute-path, and will return an Entry object corresponding to it, as long as that file exists within either the TEMPORARY or PERSISTENT filesystems.

This has particularly been an issue with the File-Transfer plugin, which previously used device-absolute-paths (and can still accept them). It has been updated to work correctly with FileSystem URLs, so replacing entry.fullPath with entry.toURL() should resolve any issues getting that plugin to work with files on the device.

In v1.1.0 the return value of toURL() was changed (see CB-6394) to return an absolute 'file://' URL. wherever possible. To ensure a 'cdvfile:'-URL you can use toInternalURL() now. This method will now return filesystem URLs of the form

cdvfile://localhost/persistent/path/to/file

which can be used to identify the file uniquely.

List of Error Codes and Meanings

When an error is thrown, one of the following codes will be used.

Code Constant
1 NOT_FOUND_ERR
2 SECURITY_ERR
3 ABORT_ERR
4 NOT_READABLE_ERR
5 ENCODING_ERR
6 NO_MODIFICATION_ALLOWED_ERR
7 INVALID_STATE_ERR
8 SYNTAX_ERR
9 INVALID_MODIFICATION_ERR
10 QUOTA_EXCEEDED_ERR
11 TYPE_MISMATCH_ERR
12 PATH_EXISTS_ERR

Configuring the Plugin (Optional)

The set of available filesystems can be configured per-platform. Both iOS and Android recognize a tag in config.xml which names the filesystems to be installed. By default, all file-system roots are enabled.

<preference name="iosExtraFilesystems" value="library,library-nosync,documents,documents-nosync,cache,bundle,root" />
<preference name="AndroidExtraFilesystems" value="files,files-external,documents,sdcard,cache,cache-external,root" />

Android

  • files: The application's internal file storage directory
  • files-external: The application's external file storage directory
  • sdcard: The global external file storage directory (this is the root of the SD card, if one is installed). You must have the android.permission.WRITE_EXTERNAL_STORAGE permission to use this.
  • cache: The application's internal cache directory
  • cache-external: The application's external cache directory
  • root: The entire device filesystem

Android also supports a special filesystem named "documents", which represents a "/Documents/" subdirectory within the "files" filesystem.

iOS

  • library: The application's Library directory
  • documents: The application's Documents directory
  • cache: The application's Cache directory
  • bundle: The application's bundle; the location of the app itself on disk (read-only)
  • root: The entire device filesystem

By default, the library and documents directories can be synced to iCloud. You can also request two additional filesystems, library-nosync and documents-nosync, which represent a special non-synced directory within the /Library or /Documents filesystem.