FileEntry

The FileEntry interface of the File System API represents a file in a file system. It lets you write content to a file.

About this document

This document was last updated on March 2, 2012 and follows the W3C Specifications (Working Draft) drafted on April 19, 2011.

This specification is more or less abandoned as it didn't get significant traction among browser makers.

Basic concepts

To write content to file, create a FileWriter object by calling createWriter().

Example

The following code creates an empty file called "log.txt" (if it doesn't exist) and fills it with the text 'Meow'. Inside the success callback, event handlers are set up for error and writeend events. The text data is written to the file by creating a blob, appending text to it, and passing the blob to FileWriter.write().

function onInitFs(fs) {

  fs.root.getFile('log.txt', {create: true}, function(fileEntry) {

    // Create a FileWriter object for our FileEntry (log.txt).
    fileEntry.createWriter(function(fileWriter) {

      fileWriter.onwriteend = function(e) {
        console.log('Write completed.');
      };

      fileWriter.onerror = function(e) {
        console.log('Write failed: ' + e.toString());
      };

      // Create a new Blob and write it to log.txt.
      var bb = new BlobBuilder(); 
     // Note: window.WebKitBlobBuilder.
      bb.append('Meow');
      
      fileWriter.write(bb.getBlob('text/plain'));

    }, errorHandler);

  }, errorHandler);

}

window.requestFileSystem(window.TEMPORARY, 1024*1024, onInitFs, errorHandler);

Properties

FileEntry.fullPath

Full path to the FileEntry (string)

FileEntry.isDirectory

If the FileEntry is a directory (Boolean)

FileEntry.isFile

If the FileEntry is a file (Boolean)

FileEntry.name

Name of the FileEntry (String)

Method overview

Methods

createWriter()

Creates a new FileWriter object associated with the selected file.

void createWriter (
 in FileWriterCallback successCallback, optional ErrorCallback errorCallback
);

Parameters

successCallback

A callback that is called with the new FileWriter object.

errorCallback

A callback that is called when errors happen.

Returns

void

file()

Returns a File object associated with the selected file. You can use this to read the file's content.

void file (
  FileCallback successCallback, optional ErrorCallback errorCallback
);

Parameters

successCallback

A callback that is called with the new File.

errorCallback

A callback that is called when errors happen.

Returns

void

Browser compatibility

See also

Specification: File API: Directories and System SpecificationWD

Reference: File System API

Introduction: Basic Concepts About the File System API