FileSystemHandle: requestPermission() method

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Check the Browser compatibility table carefully before using this in production.

The requestPermission() method of the FileSystemHandle interface requests read or readwrite permissions for the file handle.

Syntax

js
requestPermission(descriptor)

Parameters

descriptor Optional

An object which specifies the permission mode to query for. Options are as follows:

'mode' Optional

Can be either 'read' or 'readwrite'.

Return value

A Promise that resolves to a PermissionStatus object.

Exceptions

TypeError

Thrown if no parameter is specified or the mode is not that of 'read' or 'readwrite'

Examples

The following asynchronous function requests permissions if they have not been granted.

js
// fileHandle is a FileSystemFileHandle
// withWrite is a boolean set to true if write

async function verifyPermission(fileHandle, withWrite) {
  const opts = {};
  if (withWrite) {
    opts.mode = "readwrite";
  }

  // Check if we already have permission, if so, return true.
  if ((await fileHandle.queryPermission(opts)) === "granted") {
    return true;
  }

  // Request permission to the file, if the user grants permission, return true.
  if ((await fileHandle.requestPermission(opts)) === "granted") {
    return true;
  }

  // The user did not grant permission, return false.
  return false;
}

Specifications

Specification
File System Access
# api-filesystemhandle-requestpermission

Browser compatibility

BCD tables only load in the browser

See also