on-error.md

OnError

• Centralizes the business exceptions generated by Effect, whether it is a synchronous function or an asynchronous function. With a unified exception handling mechanism, we can stand on a higher level of abstraction and make reasonable simplifications of business code.
• Sample Code

bool onMessageError(Exception e, Context<String> ctx) {
    if(e is BizException) {
        ///do some toast
        return true;
    }
    return false;
}

class MessageComponent extends Component<String> {
    MessageComponent(): super(
            view: buildMessageView,
            effect: buildEffect(),
            reducer: buildMessageReducer(),
            onError: onMessageError,
        );
}