FileSystemDirectoryHandle: resolve() method

Baseline 2023

Newly available

Since March 2023, this feature works across the latest devices and browser versions. This feature might not work in older devices or browsers.

Secure context: This feature is available only in secure contexts (HTTPS), in some or all supporting browsers.

Note: This feature is available in Web Workers.

The resolve() method of the FileSystemDirectoryHandle interface returns an Array of directory names from the parent handle to the specified child entry, with the name of the child entry as the last array item.

Syntax

js
resolve(possibleDescendant)

Parameters

possibleDescendant

The FileSystemHandle from which to return the relative path.

Return value

A Promise which resolves with an Array of strings, or null if possibleDescendant is not a descendant of this FileSystemDirectoryHandle.

Exceptions

No exceptions are thrown.

Examples

The following asynchronous function uses resolve() to find the path to a chosen file, relative to a specified directory handle.

js
async function returnPathDirectories(directoryHandle) {
  // Get a file handle by showing a file picker:
  const [handle] = await self.showOpenFilePicker();
  if (!handle) {
    // User cancelled, or otherwise failed to open a file.
    return;
  }

  // Check if handle exists inside our directory handle
  const relativePaths = await directoryHandle.resolve(handle);

  if (relativePaths === null) {
    // Not inside directory handle
  } else {
    // relativePath is an array of names, giving the relative path
    for (const name of relativePaths) {
      // log each entry
      console.log(name);
    }
  }
}

Specifications

Specification
File System Standard
# api-filesystemdirectoryhandle-resolve

Browser compatibility

BCD tables only load in the browser

See also