expo-tag-reader

expo-tag-reader is an Android only Expo module that allows you to read audio file tags and metadata from your React Native Expo application. It provides simple functions to read tags from individual audio files or to scan directories for audio files and retrieve their metadata.

This was created for use in my project "Flora".

Installation

bunx expo install expo-tag-reader

Usage

First, import the functions you need from the package:

import { readTags, readAudioFiles, ... or other functions } from "expo-tag-reader";

Reading tags from a single audio file

const fileUri = "file:///path/to/your/audio/file.mp3";
try {
    const tags = readTags(fileUri);
    console.log(tags);
} catch (error) {
    console.error("Error reading tags:", error);
}

Scanning directories for audio files

try {
    // REQUEST READ PERMISSIONS FIRST
    const pageSize = 5;
    let pageNumber = 1;
    let currentPage;

    do {
        currentPage = await readAudioFiles(pageSize, pageNumber);
        pageNumber++;
        console.log(currentPage); // current page files
    } while (currentPage.length === pageSize);
} catch (error) {
    console.error("Error reading audio files:", error);
}

API Reference

readTags()

Reads the tags from the audio file at the given URI.

• fileUri: The URI of the audio file to read tags from.
• disableTags (optional): Add any of the AudioFile properties to ignore.
• cacheImages (optional): Whether to cache album art images. Defaults to true. If caching is enabled, the artwork property of AudioTags will be a URI, otherwise it will be Base64.
• Returns: An object of type AudioTags.

readAudioFiles()

Reads all audio files from the Music and Downloads directory.

• pageSize (optional): The number of audio files to return per page. Defaults to 10.
• pageNumber: The page number to return. Defaults to 1.
• cacheImages (optional): Whether to cache album art images. Defaults to true.
• disableTags (optional): Add any of the AudioFile properties to ignore.
• Returns: A Promise that resolves with an array of objects of type AudioFile.

setCustomDirectories()

Sets the custom directories to read audio files from.

• dirPaths: An array of paths to directories that contain audio files.
• Returns: A Promise that resolves when the operation is complete.

readNewAudioFiles()

Finds and returns new audio files by comparing IDs.

• songIds: The IDs of the songs to read new files from.
• pageSize (optional): The number of audio files to return per page. Defaults to 10.
• pageNumber: The page number to return. Defaults to 1.
• cacheImages (optional): Whether to cache album art images. Defaults to true.
• disableTags (optional): Add any of the AudioFile properties to ignore.
• Returns: A Promise that resolves with an array of objects of type AudioFile.

getRemovedAudioFiles()

Finds and returns the removed audio files by comparing IDs.

• songIds: The IDs of the songs to find removed files from.
• Returns: A Promise that resolves with an array of strings of removed file IDs.

Types

AudioTags

type AudioTags = {
    title: string;
    artist: string;
    album: string;
    year: string;
    genre: string;
    track: string;
    comment: string;
    albumArt: string; // URI or Base64 (default: URI)
    sampleRate: string;
    bitrate: string;
    channels: string;
    duration: string; // in ms
};

AudioFile

type AudioFile = {
    extension: string;
    uri: string;
    fileName: string;
    tags: AudioTags;
    creationDate: string; // in "dd-MM-yyyy"
    internalId: string; // unique identifier for the audio file
};

Supported File Formats

The module supports reading tags from the following audio file formats:

• MP3
• WAV
• OGG
• FLAC
• M4A
• OPUS
• AIF
• DSF
• WMA

Platform Support

This module is currently implemented for Android only.

Important Notes

• Remember to request read permissions before calling any of the audio file reading functions.
• Caching images is faster than using base64 images on subsequent reads.
• The internalId property in the AudioFile type is essential for tracking new and removed files.