How to map error from sendError: on RACSignal

Question

This is very cumbersome

RACSignal *originalSignal = ...;

RACSignal *mappedSignal = [[[[[originalSignal publish] autoconnect] materialize] map:^id(RACEvent *event) {
    if(event.eventType == RACEventTypeError)
    {
        return [RACEvent eventWithError:[self errorForHelperError:event.error]];
    }
    return event;
}] dematerialize];

Answer 1

-catch: lets you handle this much more elegantly:

RACSignal *mappedSignal = [originalSignal catch:^(NSError *error) {
    return [RACSignal error:[self errorForHelperError:error]];
}];