addAnnotation method

Future<Annotation?> addAnnotation(Annotation annotation)

Adds a typed annotation to the document.

Returns the created annotation parsed back from the platform, or null if the platform did not return a parseable result.

Annotations that carry binary content mix in HasAttachment — currently ImageAnnotation and RichMediaAnnotation. For those, the AnnotationAttachment's Base64 binary + contentType are forwarded to the platform so the annotation renders; the binary travels out-of-band via addAnnotationJson's attachment argument rather than inline in the Instant JSON. Other types (including StampAnnotation) don't carry an attachment and are written from their Instant JSON alone.

Implementation

Future<Annotation?> addAnnotation(Annotation annotation) async {
  String? attachment;
  if (annotation is HasAttachment) {
    final att = (annotation as HasAttachment).attachment;
    if (att != null && att.binary.isNotEmpty) {
      attachment = jsonEncode(att.toJson());
    }
  }
  final created = await addAnnotationJson(
    jsonEncode(annotation.toJson()),
    attachment: attachment,
  );
  if (created.isEmpty) return null;
  try {
    final decoded = jsonDecode(created);
    if (decoded is Map) {
      return Annotation.tryFromJson(Map<String, dynamic>.from(decoded));
    }
  } catch (_) {}
  return null;
}