exec method

Implementation

@override
Future<void> exec() async {
  // unlike
  if (reaction.uri != null) {
    reaction.count -= 1;
    await plugin.unlike(reaction.uri!);
    reaction.uri = null;
  }
  // like
  else {
    reaction.count += 1;
    Tuple2 res = await plugin.like(post.uri, post.cid);
    reaction.uri = res.item2['uri'];
  }
}