How to differentiate whether its ebook or Audio Book..?.

[ManjunathIOS]

Hi Team,
How to differentiate whether its ebook or Audio Book..?.
We have requirement to show Custom UI for the Audio Books.
In the last version of R2 ,I am using “Publication.formatVersion”
For ebook it used return “2.0”
For Audio book it used return “3.0”
But in the latest version I am getting “Publication.formatVersion” value as “nil”.
Is there any other options…?

Thanks in Advance.

[mickael-menu]

Readium Audiobook is not yet supported in the Swift toolkit, so I wonder what do you mean exactly by audiobook? Is it an EPUB 3 with audio files inside? For the rest of this answer I will assume that you mean a real Readium Audiobook.

Publication.formatVersion

This property is actually for checking which publication format version a publication is. For example EPUB "2.0" or EPUB "3.0". This was not used for other media types (PDF, audiobooks) and is now deprecated as we don't have any use for it in the models.

So checking for ebook vs audiobook with formatVersion was actually wrong and I'm surprised it gave consistent results for you.

How to check the media type of a publication? (2.0.0-beta.1+)

Since the version 2.0.0-beta.1, you need to create an instance of FileAsset to open a publication with a Streamer. You can also use this object to check the media type of a publication.

let file = FileAsset(url: url)
if let type = file.mediaType() {
    switch type {
    case .epub:
        break
    case .pdf:
        break
    case .readiumAudiobook, .readiumAudiobookManifest, .lcpProtectedAudiobook:
        break
    ....
    }
}

Bonus: an EPUB 3 with audio files

If your use case is to play only the audio files embedded in an EPUB 3, you can't use the media type because there's only a single media type for EPUB. However you can do something like this:

let audioResources = publication.resources
    .filter { link in link.mediaType.isAudio }

if !audioResources.isEmpty {
    // Play the audio...
}

However there's no guarantee that the audio resources are added in order in publication.resources. It depends on how they are declared in the OPF.