FileSystemEntry.getParent() - Web APIs 编辑

Experimental

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

The FileSystemEntry interface's method getParent() obtains a FileSystemDirectoryEntry.

Syntax

FileSystemEntry.getParent(successCallback[, errorCallback]);

Parameters

successCallback

A function which is called when the parent directory entry has been retrieved. The callback receives a single input parameter: a FileSystemDirectoryEntry object representing the parent directory. The parent of the root directory is considered to be the root directory, itself, so be sure to watch for that.

errorCallback Optional

An optional callback which is executed if an error occurs. There's a single parameter: a FileError describing what went wrong.

Return value

undefined.

Errors

FileError.INVALID_STATE_ERR

The operation failed because the file system's state doesn't permit it. This can happen, for example, if the file system's cached state differs from the actual state of the file system.

FileError.NOT_FOUND_ERR

The specified path could not be found.

FileError.SECURITY_ERR

Security restrictions prohibit obtaining the parent directory's information.

Example

This example renames  the file specified by the variable fileEntry to "newname.html".

fileEntry.getParent(function(parent) {
  fileEntry.moveTo(parent, "newname.html", function(updatedEntry) {
    console.log("File " + fileEntry.name + " renamed to newname.html.");
  });
}, function(error) {
  console.error("An error occurred: Unable to rename " + fileEntry.name
        + " to newname.html.");
});

This is accomplished by first obtaining a FileSystemDirectoryEntry object representing the directory the file is currently located in. Then moveTo() is used to rename the file within that directory.

Using promises

Currently, there isn't a Promise-based version of this method. You can, however, create a simple helper function to adapt it, like this:

function getParentPromise(entry) {
  return new Promise((resolve, reject) => {
    entry.getParent(resolve, reject);
  });
}

A similar approach can be taken elsewhere in the File and Directory Entries API.

Specifications

Browser compatibility

BCD tables only load in the browser

See also

• File and Directory Entries API
• Introduction to the File System API