cordova-plugin-file

cordova-plugin-file

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.

This plugin defines global cordova.file object.

Although in the global scope, it is not available until after the deviceready event.

document.addEventListener("deviceready", onDeviceReady, false);
function onDeviceReady() {
    console.log(cordova.file);
}

Installation

cordova plugin add cordova-plugin-file

Supported Platforms

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

* 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 Internal 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- 3.0.0) version of this plugin, and has stored files in the persistent filesystem, then you should set the preference to Compatibility if your config.xml does not specify a location for the persistent filesystem. 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.

Slow recursive operations for /android_asset

Listing asset directories is really slow on Android. You can speed it up though, by adding src/android/build-extras.gradle to the root of your android project (also requires cordova-android@4.0.0 or greater).

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).

Browser Quirks

Common quirks and remarks

• Each browser uses its own sandboxed filesystem. IE and Firefox use IndexedDB as a base. All browsers use forward slash as directory separator in a path.
• Directory entries have to be created successively. For example, the call fs.root.getDirectory('dir1/dir2', {create:true}, successCallback, errorCallback) will fail if dir1 did not exist.
• The plugin requests user permission to use persistent storage at the application first start.
• Plugin supports cdvfile://localhost (local resources) only. I.e. external resources are not supported via cdvfile.
• The plugin does not follow "File System API 8.3 Naming restrictions".
• Blob and File' close function is not supported.
• FileSaver and BlobBuilder are not supported by this plugin and don't have stubs.
• The plugin does not support requestAllFileSystems. This function is also missing in the specifications.
• Entries in directory will not be removed if you use create: true flag for existing directory.
• Files created via constructor are not supported. You should use entry.file method instead.
• Each browser uses its own form for blob URL references.
• readAsDataURL function is supported, but the mediatype in Chrome depends on entry name extension, mediatype in IE is always empty (which is the same as text-plain according the specification), the mediatype in Firefox is always application/octet-stream. For example, if the content is abcdefg then Firefox returns data:application/octet-stream;base64,YWJjZGVmZw==, IE returns data:;base64,YWJjZGVmZw==, Chrome returns data:<mediatype depending on extension of entry name>;base64,YWJjZGVmZw==.
• toInternalURL returns the path in the form file:///persistent/path/to/entry (Firefox, IE). Chrome returns the path in the form cdvfile://localhost/persistent/file.

Chrome quirks

• Chrome filesystem is not immediately ready after device ready event. As a workaround you can subscribe to filePluginIsReady event. Example:

window.addEventListener('filePluginIsReady', function(){ console.log('File plugin is ready');}, false);

You can use window.isFilePluginReadyRaised function to check whether event was already raised.

• window.requestFileSystem TEMPORARY and PERSISTENT filesystem quotas are not limited in Chrome.
• To increase persistent storage in Chrome you need to call window.initPersistentFileSystem method. Persistent storage quota is 5 MB by default.
• Chrome requires --allow-file-access-from-files run argument to support API via file:/// protocol.
• File object will be not changed if you use flag {create:true} when getting an existing Entry.
• events cancelable property is set to true in Chrome. This is contrary to the specification.
• toURL function in Chrome returns filesystem:-prefixed path depending on application host. For example, filesystem:file:///persistent/somefile.txt, filesystem:http://localhost:8080/persistent/somefile.txt.
• toURL function result does not contain trailing slash in case of directory entry. Chrome resolves directories with slash-trailed urls correctly though.
• resolveLocalFileSystemURL method requires the inbound url to have filesystem prefix. For example, url parameter for resolveLocalFileSystemURL should be in the form filesystem:file:///persistent/somefile.txt as opposed to the form file:///persistent/somefile.txt in Android.
• Deprecated toNativeURL function is not supported and does not have a stub.
• setMetadata function is not stated in the specifications and not supported.
• INVALID_MODIFICATION_ERR (code: 9) is thrown instead of SYNTAX_ERR(code: 8) on requesting of a non-existant filesystem.
• INVALID_MODIFICATION_ERR (code: 9) is thrown instead of PATH_EXISTS_ERR(code: 12) on trying to exclusively create a file or directory, which already exists.
• INVALID_MODIFICATION_ERR (code: 9) is thrown instead of NO_MODIFICATION_ALLOWED_ERR(code: 6) on trying to call removeRecursively on the root file system.
• INVALID_MODIFICATION_ERR (code: 9) is thrown instead of NOT_FOUND_ERR(code: 1) on trying to moveTo directory that does not exist.

IndexedDB-based impl quirks (Firefox and IE)

• . and .. are not supported.
• IE does not support file:///-mode; only hosted mode is supported (http://localhost:xxxx).
• Firefox filesystem size is not limited but each 50MB extension will request a user permission. IE10 allows up to 10mb of combined AppCache and IndexedDB used in implementation of filesystem without prompting, once you hit that level you will be asked if you want to allow it to be increased up to a max of 250mb per site. So size parameter for requestFileSystem function does not affect filesystem in Firefox and IE.
• readAsBinaryString function is not stated in the Specs and not supported in IE and does not have a stub.
• file.type is always null.
• You should not create entry using DirectoryEntry instance callback result which was deleted. Otherwise, you will get a 'hanging entry'.
• Before you can read a file, which was just written you need to get a new instance of this file.
• setMetadata function, which is not stated in the Specs supports modificationTime field change only.
• copyTo and moveTo functions do not support directories.
• Directories metadata is not supported.
• Both Entry.remove and directoryEntry.removeRecursively don't fail when removing non-empty directories - directories being removed are cleaned along with contents instead.
• abort and truncate functions are not supported.
• progress events are not fired. For example, this handler will be not executed:

writer.onprogress = function() { /*commands*/ };

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] (https://issues.apache.org/jira/browse/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.