filesystem

Reads and writes local files through the File System Access API's open/save pickers.

Import: @rtorcato/browser-common/filesystem

📖 MDN: File System Access API

The File System Access API is Chromium-only and pickFiles/saveFile must be called from a user gesture (e.g. a click handler) — both throw a File System Access API not available error where unsupported, so guard with isFileSystemApiAvailable() first.

Browser support

API	Chrome	Edge	Firefox	Safari	iOS Safari	Baseline
Window.showOpenFilePicker	✅ 86+	✅ 86+	❌	❌	❌	Limited
Window.showSaveFilePicker	✅ 86+	✅ 86+	❌	❌	❌	Limited

✅ supported · ◐ partial · ❌ not supported · [n] see note. Generated from MDN browser-compat-data and web-features. caniuse: Window.showOpenFilePicker · Window.showSaveFilePicker

Example

import {
  isFileSystemApiAvailable,
  pickFiles,
  saveFile,
  writeTextToFile,
} from '@rtorcato/browser-common/filesystem'

if (isFileSystemApiAvailable()) {
  const files = await pickFiles({ multiple: true })

  const stream = await saveFile({ suggestedName: 'notes.txt' })
  await writeTextToFile(stream, 'hello')
}

Exports

• isFileSystemApiAvailable() — feature check
• pickFiles(options?) — prompts the user to select files, returns File[]
• saveFile(options?) — prompts the user to save a file, returns a writable file stream
• readFileAsText(file) — reads a File as text
• readFileAsArrayBuffer(file) — reads a File as an ArrayBuffer
• writeTextToFile(stream, text) — writes text to a writable stream and closes it
• writeDataToFile(stream, data) — writes a Blob/ArrayBuffer to a writable stream and closes it

See the API reference for full signatures.