A promisified FileReader for browsers

A promisified FileReader implementation very similar to the browser's FileReader API, with a few differencies:

• the File or Blob instance is given at construction time;
• all readAs... methods don't take a Blob or File instance as first argument anymore;
• all readAs... methods return a Promise that can be awaited;
• reading in chunks is easy as:
  • you just need to await the next chunk (no event / callback API anymore);
  • the current reading position is automatically tracked.

Usage

import FileReader from '@tanker/file-reader';

// Retrieve a file or blob somehow
const file = new File(['The quick brown fox jumps over the lazy dog'], 'fox.txt', { type: 'plain/text' });

// Create your file reader
const reader = new FileReader(file);

// Read the whole file
const text = await reader.readAsText('UTF-8');
const dataUrl = await reader.readAsDataURL();
const arrayBuffer = await reader.readAsArrayBuffer();

// Or read binary chunks (ArrayBuffer)
const chunkSize = 8; // bytes
let chunk;
do {
  chunk = await reader.readAsArrayBuffer(chunkSize);
  // do something with the chunk
} while (chunk.byteLength > 0);

License

Developped by Tanker, under the Apache-2.0 license.

Tanker allows seamless integration of end-to-end encryption in your application.

Read the documentation to get started.

Go to tanker.io for more informations about Tanker.