This is an experimental technology
Check the Browser compatibility table carefully before using this in production.
Obsolete
This feature is obsolete. Although it may still work in some browsers, its use is discouraged since it could be removed at any time. Try to avoid using it.
Non-standard
This feature is non-standard and is not on a standards track. Do not use it on production sites facing the Web: it will not work for every user. There may also be large incompatibilities between implementations and the behavior may change in the future.
The FileSystemFileEntry
interface's method createWriter()
returns a FileWriter
object which can be used to write data into the file represented by the directory entry.
FileSystemFileEntry.createWriter(successCallback[, errorCallback]);
successCallback
FileWriter
has been created successfully; the FileWriter
is passed into the callback as the only parameter.errorCallback
Optional
FileWriter
. This callback receives as input a FileError
object describing the error.This example establishes a method, writeToFileEntry()
, which outputs a text string to the file corresponding to the passed-in directory entry.
function writeToFileEntry(entry, text) { entry.createWriter(function(fileWriter) { let data = Blob([text], { type: "text/plain" }); fileWriter.write(data); }, function(fileError) { /* do whatever to handle the error */ }); }
The success callback for the createWriter()
call takes the text which was passed in and creates a new Blob
object of type text/plain
that contains the passed text. This blob is then output to the FileWriter
object to be written to the file.
Specification | Status | Comment |
---|---|---|
File and Directory Entries API The definition of 'createWriter()' in that specification. | Draft | Initial specification. |
This API has no official W3C or WHATWG specification.
Desktop | ||||||
---|---|---|---|---|---|---|
Chrome | Edge | Firefox | Internet Explorer | Opera | Safari | |
Basic support | 13 | No | 50 — 52
|
No | No | No |
Mobile | |||||||
---|---|---|---|---|---|---|---|
Android webview | Chrome for Android | Edge Mobile | Firefox for Android | Opera for Android | iOS Safari | Samsung Internet | |
Basic support | Yes | Yes | No | 50 — 52
|
No | No | ? |
© 2005–2018 Mozilla Developer Network and individual contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/FileSystemFileEntry/createWriter