This is an experimental technology
Check the Browser compatibility table carefully before using this in production.
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 FileSystemFlags dictionary defines a set of values which are used when specifying option flags when calling certain methods in the File and Directory Entries API. Methods which accept an options parameter of this type may specify zero or more of these flags as fields in an object, like this:
dataDirectoryEntry.getDirectory("Workspace", { create: true }, function(entry) {
});
Here, we see that the create property is provided, with a value of true, indicating that the directory should be created if it's not already there.
Note that these option flags currently don't have any useful meaning when used in the scope of Web content, where security precautions prevent the creation of new files or the replacement of existing ones.
Properties
createOptional- If this property is
true, and the requested file or directory doesn't exist, the user agent should create it. The default isfalse. The parent directory must already exist. exclusiveOptional- If
true, and thecreateoption is alsotrue, the file must not exist prior to issuing the call. Instead, it must be possible for it to be created newly at call time. The default isfalse.
Values and results
The table below describes the result of each possible combination of these flags depending on whether or not the target file or directory path already exists.
| Option values | File/directory condition | Result | ||
|---|---|---|---|---|
create |
exclusive |
|||
false |
n/a[1] | Path exists and matches the desired type (depending on whether the function called is getFile() or getDirectory() |
The successCallback is called with a FileSystemFileEntry if getFile() was called or a FileSystemDirectoryEntry if getDirectory() was called. |
|
false |
n/a[1] | Path exists but doesn't match the desired type | The errorCallback is called with an appropriate error code (if the callback was provided). |
|
true |
false |
Path exists | The existing file or directory is removed and replaced with a new one, then the successCallback is called with a FileSystemFileEntry or a FileSystemDirectoryEntry, as appropriate. |
|
true |
false |
Path doesn't exist | The file or directory is created, then a FileSystemFileEntry or a FileSystemDirectoryEntry is passed to the successCallback, as appropriate. |
|
true |
true |
Path exists | The errorCallback is called with an appropriate error, such as FileError.PATH_EXISTS_ERR. |
|
true |
true |
Path doesn't exist | The file or directory is created, then a FileSystemFileEntry or a FileSystemDirectoryEntry is passed to the successCallback, as appropriate. |
|
[1] When create is false, the value of exclusive is irrelevant and ignored.
Specifications
| Specification | Status | Comment |
|---|---|---|
| File and Directory Entries API The definition of 'FileSystemFlags' in that specification. |
Draft | Initial specification. |
This API has no official W3C or WHATWG specification.
Browser compatibility
| Feature | Chrome | Edge | Firefox | Internet Explorer | Opera | Safari |
|---|---|---|---|---|---|---|
| Basic support | 13 webkit | ? | 50 | No | No | No |
create | 13 webkit | ? | 501 | No | No | No |
exclusive | 13 webkit | ? | 501 | No | No | No |
| Feature | Android webview | Chrome for Android | Edge mobile | Firefox for Android | Opera Android | iOS Safari | Samsung Internet |
|---|---|---|---|---|---|---|---|
| Basic support | Yes webkit | Yes webkit | ? | 50 | No | No | ? |
create | Yes webkit | Yes webkit | ? | 501 | No | No | ? |
exclusive | Yes webkit | Yes webkit | ? | 501 | No | No | ? |
1. For security reasons, Firefox does not support creating files. This option has no effect.