This is a generic implementation of prepareForSegue:sender: that calls a segue-specific method based on the segue identifier. There's also a similar implementation of shouldPerformSegueWithIdentifier:sender:.

GenericPrepareForSegue.m

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
    NSString *identifier = segue.identifier;
    if (identifier.length == 0)
        return;
    NSString *selectorString = [NSString stringWithFormat:@"prepareFor%@Segue:sender:", identifier];
    SEL selector = NSSelectorFromString(selectorString);
    if (!selector || ![self respondsToSelector:selector])
        return;
    void (*method)(id, SEL, id, id) = (void (*)(id, SEL, id, id))[self methodForSelector:selector];
    method(self, selector, segue, sender);
}

- (BOOL)shouldPerformSegueWithIdentifier:(NSString *)identifier sender:(id)sender {
    if (identifier.length == 0)
        return YES;
    NSString *selectorString = [NSString stringWithFormat:@"shouldPerform%@SegueWithSender:", identifier];
    SEL selector = NSSelectorFromString(selectorString);
    if (!selector || ![self respondsToSelector:selector])
        return YES;
    BOOL (*method)(id, SEL, id) = (BOOL (*)(id, SEL, id))[self methodForSelector:selector];
    return method(self, selector, sender);
}

This implementation of prepareForSegue:sender: automatically calls a method specific to the segue. It constructs the segue-specific method name (selector) using the format prepareFor%@Segue:sender:, and substitutes the segue identifier for %@. So, for example, if you create a segue with the identifier DetailPushing, it will check for a method named prepareForDetailPushingSegue:sender: and call the method if it exists.

There is also a similar implementation of shouldPerformSegueWithIdentifier:sender:. It constructs the segue-specific method name using the format shouldPerform%@SegueWithSender:. It only passes the sender, and not the segue identifier, to the segue-specific method. So, for example, if you create a segue with the identifier DetailPushing, it will check for a method named shouldPerformDetailPushingSegueWithSender: and call the method if it exists. It will return whatever the segue-specific method returns. If it can't find a method-specific segue, it just returns YES.