Native file picker APIs do not return native path of the local file

[ssnangua]

Issue Type

• Feature Request

Current/Missing Behavior

The native web API showOpenFilePicker(), showSaveFilePicker() and showDirectoryPicker() do not return native path of the local file.

Expected/Proposed Behavior

The returned FileSystemFileHandle object or FileSystemDirectoryHandle object contain native path of the local file, such as path.

Additional Info

Compared to creating an <input type="file">, this is a more convenient way to show a file picker.
In addition, support for setting MIME type groups is also very useful.

• Code snippet:

window
  .showOpenFilePicker({
    types: [
      { description: "JPEG", accept: { "image/jpeg": [".jpeg", ".jpg"] } },
      { description: "PNG", accept: { "image/png": [".png"] } },
      { description: "GIF", accept: { "image/gif": [".gif"] } },
    ],
    excludeAcceptAllOption: true,
    multiple: false,
  })
  .then(([fileHandle]) => {
    console.log(fileHandle);
  });

[ayushmanchhabra]

For historical reasons, the value IDL attribute prefixes the filename with the string "C:\fakepath". Some legacy user agents actually included the full path (which was a security vulnerability). As a result of this, obtaining the filename from the value IDL attribute in a backwards-compatible way is non-trivial.

https://html.spec.whatwg.org/multipage/input.html#fakepath-srsly

This is probably why FileSystemHandle and similar APIs don't provide the native path.