How get input data in UpdateCacheHandler?

[Feduch]

Hi!

How get input data from mutation in body UpdateCacheHandler?

final UpdateCacheHandler<$MyMutation> myMutationHandler = (
  CacheProxy proxy,
  QueryResponse<$MyMutation> response,
) {
  final query = MyQueryToUpdate();
  final result = proxy.readQuery(query);

  /// update the result
  proxy.writeQuery(query, result);
};

[smkhalsa]

You can access the mutation via the queryRequest property on QueryResponse.

Also, if you want to pass in additional data that isn't an input to the mutation, you can pass in a Context object when creating the mutation.

For example:

/// Create a ContextEntry subclass
class UserContextEntry extends ContextEntry {
  final String userId;

  UserContextEntry(this.userId);

  @override
  List<Object> get fieldsForEquality => [userId];
}

/// When instantiating your mutation...
final mutation = MyMutation(
  updateCacheHandlerKey: "myMutationKey",
  /// ...pass in an instance of the ContextEntry subclass
  context: Context.fromList([UserContextEntry("user123")]),
);

final UpdateCacheHandler<$MyMutation> myMutationHandler = (
  CacheProxy proxy,
  QueryResponse<$MyMutation> response,
) {
  final query = MyQueryToUpdate();
  final result = proxy.readQuery(query);

  /// Access the data passed in through ContextEntry
  final userId = response.queryRequest.context.entry<UserContextEntry>().userId;

  /// update the result
  proxy.writeQuery(query, result);
};

I recognize that subclassing ContextEntry as demonstrated above just to pass in a userId String is a bit verbose. I'm open to suggestions to improve the API (@klavs any thoughts here)?