Node.js FS API wrapper for the Web File System
Switch branches/tags
Nothing to show
Clone or download
Fetching latest commit…
Cannot retrieve the latest commit at this time.
Failed to load latest commit information.

WebFS - Nodejs filesystem implementation for Client Side

WebFS by is a client side implementation of the nodejs filesystem. It provides all the async functions required to handle reading and writing of file and directories by using the W3C FileSystem API.


To use the library, include the webfs.js in your documents script tags and create a new WebFS object.


<!doctype html>
        <title>Test Page</title>
        <script type="text/javascript" src="jquery.js"></script>
        <script type="text/javascript" src="webfs.js"></script>
        <script type="text/javascript">
            var webfs = new WebFS();
            // Create a temporary file system of 500Mb
            webfs.setFileSystem(webfs.TEMPORARY, 500, function(error, wfs) {
                // Read the contents of foo.txt
                webfs.readFile('foo.txt', function(error, read, buffer) {
                    if (error) {
                    } else {                
                        // Get the string content of the buffer(Blob) passed back
                        webfs.readString(buffer, function(error, string) {;
        <div id="content"></div>

WebFS Available Members and Functions

On the WebFS object, the following objects are available:

webfs.fs - The native file system object. webfs.root - The root directory of the native filesystem sandbox.

The following WebFS functions are available:

webfs.isAvailable() - Helper method to advise if requestFileSystem is available in the browser.

webfs.setFileSystem(type, size, callback) - If a native filesystem is not passed to the constructor use this function to se the filesystem. Type can be webfs.TEMPORARY or web.fs.PERSISTENT. Size is in MB.

webfs.getFileSystem() - Returns the native file system handler.

webfs.createBlob(data, encoding) - Creates a blob from the passed data with the mimetype encoding passed. If not mimetype is passed it will be raw binary data.

webfs.readString(data, encoding, callback) - Returns a string from a passed Blob with the passed encoding. If not encoding is passed, the default is 'UTF-8'.

webfs.readBinaryString(data, callback) - Returns a binary string from the passed Blob.

webfs.readArrayBuffer(data, callback) - Returns an array buffer from the passed Blob.

webfs.readDataUrl(data, callback) - Returns a base64 dataurl from the passed Blob.

The following functions are available nodejs-style functions:

webfs.rename(source, dest, callback) - Rename or move a file or directory.

webfs.truncate(fd, length, callback) - Truncate a file passed in the file descriptor to the length provided.

webfs.stat|lstat(path, callback) - Returns a stat object for the path.

webfs.fstat(fd, callback) - Returns a stat object for the passed file descriptor.

webfs.unlink|rmdir(path, callback) - Removes the passed path from the filesystem, can be a file or directory. Directories are removed recursivly.

webfs.mkdir(path, mode, callback) - Creates a directory from the path, directories are created recursivly. Mode is not used and only provided for compatibility.

webfs.readdir(path, callback) - Returns an array of paths to files and directories within the passed path.

webfs.close(fd, callback) - Destroys the passed filehandler reference., flags, mode, callback) - Returns a file descriptor for the passed path. If the flag is one of ['w', 'w+', 'a', 'a+'] the file will be created if it does not exist. Mode is not used and provided for nodejs compatibility.

webfs.write(fd, buffer, offset, length, position, callback) - Writes the buffer to the passed file handler. Offset, length, position are not used and provided for nodejs compatibility. Buffer can be a File, Blob or String.

webfs.writeFile(path, data, encoding, callback) - Writes the data to the passed file path, if the file does not exist it will be created. Encoding is not used and provided for nodejs compatibility., buffer, offset, length, position, callback) - Reads the contents of the file description and places into the buffer. Offset, length, position are not used and provided for nodejs compatibility.

webfs.readFile(path, encoding, callback) - Reads the content of the file passed as path. Encoding is not used and provided for nodejs compatibility.

The following functions are available nodejs-style functions that return an empty callback, only provided for compatibility

webfs.chmod(path, mode, callback), destpath, callback)

webfs.symlink(linkdata, path, callback)

webfs.readlink(path, callback)

webfs.realpath(path, callback)