lpf static method

Future<MediaType?> lpf(SnifferContext context)

Sniffs a Lightweight Packaging MediaType (LPF).

References:

• https://www.w3.org/TR/lpf/
• https://www.w3.org/TR/pub-manifest/

Implementation

static Future<MediaType?> lpf(SnifferContext context) async {
  if (context.hasFileExtension(["lpf"]) ||
      context.hasMediaType("application/lpf+zip")) {
    return MediaType.lpf;
  }
  if (await context.containsArchiveEntryAt("index.html")) {
    return MediaType.lpf;
  }

  // Somehow, [JSONObject] can't access JSON-LD keys such as `@context`.
  MediaType? mediaType =
      (await context.readArchiveEntryAt("publication.json"))
          ?.let((it) => utf8.decode(it.buffer.asUint8List()))
          .let((manifest) {
    if (manifest.contains("@context") &&
        manifest.contains("https://www.w3.org/ns/pub-context")) {
      return MediaType.lpf;
    }
    return null;
  });

  return mediaType;
}