LockedFile - Web APIs 编辑

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.

Summary

The LockedFile interface provides tools to deal with a given file with all the necessary locks.

Properties

LockedFile.fileHandle Read only

The FileHandle object from which the lock was opened.

LockedFile.mode Read only

The mode for accessing the file; can be readonly or readwrite.

LockedFile.active Read only

A flag indicating if the file can be accessed (true) or not (false).

LockedFile.location

The position of the reading/writing pointer within the file.

Events Handler

LockedFile.oncomplete

The complete event is triggered each time a read or write operation is successful.

LockedFile.onabort

The abort event is triggered each time the abort() method is called.

LockedFile.onerror

The error event is triggered each time something goes wrong.

Methods

LockedFile.getMetadata()

Allows to retrieve the file metadata (size and date of the last modification). Returns a FileRequest.

LockedFile.readAsArrayBuffer()

Allows to retrieve a part of the content of the file as an ArrayBuffer. Returns a FileRequest object.

LockedFile.readAsText()

Allows to retrieve a part of the content of the file as a string. Returns a FileRequest object.

LockedFile.write()

Allows to write some data in the file starting at the location offset. Returns a FileRequest object.

LockedFile.append()

Allows to write some data at the end of the file. Returns a FileRequest object.

LockedFile.truncate()

Allows to truncate the file's content. Returns a FileRequest object.

LockedFile.flush()

Allows to guarantee that any buffered data has been transferred to disk.

LockedFile.abort()

Makes the LockedFile inactive and cancels all ongoing operations.

Specifications

See also

• FileHandle
• FileRequest