The FileSystemHandle
interface of the File System API
is an object which represents a file or directory entry. Multiple handles can represent the same entry. For the most part you do not work with FileSystemHandle
directly but rather its child interfaces FileSystemFileHandle
and FileSystemDirectoryHandle
.
Below is a list of interfaces based on the FileSystemHandle interface.
FileSystemFileHandle
-
Represents a handle to a file entry.
FileSystemDirectoryHandle
-
Provides a handle to a directory entry.
The below code allows the user to choose a file from the file picker and then tests to see whether the handle returned is a file or directory
let fileHandle;
async function getFile() {
[fileHandle] = await window.showOpenFilePicker();
if (fileHandle.kind === "file") {
} else if (fileHandle.kind === "directory") {
}
}
The following asynchronous function returns true if user has granted read or readwrite permissions to the file handle. Permission is requested if not.
async function verifyPermission(fileHandle, withWrite) {
const opts = {};
if (withWrite) {
opts.mode = "readwrite";
}
if ((await fileHandle.queryPermission(opts)) === "granted") {
return true;
}
if ((await fileHandle.requestPermission(opts)) === "granted") {
return true;
}
return false;
}
The following function compares a single entry with an array of entries, and returns a new array with any matching entries removed.
function removeMatches(fileEntry, entriesArr) {
const newArr = entriesArr.filter((entry) => !fileEntry.isSameEntry(entry));
return newArr;
}