Faq

how can i delete item with repeated field?

Basically, protobuf doesn't provide API which arbitrarily remove an element from within a repeated field. You should define a helper method on helper class and use it. someday I'll add helper class for generic usage.

can we implement business logic on message class?

We strongly disagree with this opinion. the message class is just container. You should wrap the message class or add some business logic class which modify message from outside.

first, please check Google's tutorial