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FileSystemFlags - Web APIs 编辑

Experimental

This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

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

create Optional: If this property is true, and the requested file or directory doesn't exist, the user agent should create it. The default is false. The parent directory must already exist.
exclusive Optional: If true, and the create option is also true, 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 is false.

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`	File/directory condition	Result
`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.

Browser compatibility

BCD tables only load in the browser

FileSystemFlags - Web APIs 编辑

Experimental

Properties

Values and results

Specifications

Browser compatibility

See also

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友情链接

FileSystemFlags - Web APIs 编辑

Experimental

Properties

Values and results

Specifications

Browser compatibility

See also

如果你对这篇内容有疑问，欢迎到本站社区发帖提问 参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。

发布评论

词条统计

友情链接

如果你对这篇内容有疑问，欢迎到本站社区发帖提问参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。