The File and Directory Entries API simulates a local file system that web apps can navigate within and access files in. You can develop apps which read, write, and create files and/or directories in a virtual, sandboxed file system.

There are two ways to get access to file systems defined in the current specification draft:

• When handling a drop event for drag and drop, you can call DataTransferItem.webkitGetAsEntry() to get the FileSystemEntry for a dropped item. If the result isn't null, then it's a dropped file or directory, and you can use file system calls to work with it.
• The HTMLInputElement.webkitEntries property lets you access the FileSystemFileEntry objects for the currently selected files, but only if they are dragged-and-dropped onto the file chooser (Firefox bug 1326031). If HTMLInputElement.webkitdirectory is true, the <input> element is instead a directory picker, and you get FileSystemDirectoryEntry objects for each selected directory.

The File and Directory Entries API includes the following interfaces:

FileSystem

Represents a file system.

FileSystemEntry

The basic interface representing a single entry in a file system. This is implemented by other interfaces which represent files or directories.

FileSystemFileEntry

Represents a single file in a file system.

FileSystemDirectoryEntry

Represents a single directory in a file system.

FileSystemDirectoryReader

Created by calling FileSystemDirectoryEntry.createReader(), this interface provides the functionality which lets you read the contents of a directory.

• Introduction to the File and Directory Entries API
• File and Directory Entries API support in Firefox