extract static method

Future<Metadata?> extract(String url)

Fetches a url, validates it, and returns Metadata.

Implementation

static Future<Metadata?> extract(String url) async {
  if (!isURL(url)) {
    return null;
  }

  /// Sane defaults; Always return the Domain name as the [title], and a [description] for a given [url]
  final defaultOutput = Metadata();
  defaultOutput.title = getDomain(url);
  defaultOutput.description = url;

  // Make our network call
  final response = await http.get(Uri.parse(url));
  final headerContentType = response.headers['content-type'];

  if (headerContentType != null && headerContentType.startsWith(r'image/')) {
    defaultOutput.title = '';
    defaultOutput.description = '';
    defaultOutput.image = url;
    return defaultOutput;
  }

  final document = responseToDocument(response);

  if (document == null) {
    return defaultOutput;
  }

  final data = _extractMetadata(document);
  if (data == null) {
    return defaultOutput;
  }

  return data;
}