Pre- and Post-Processing Hooks

You can ask maki::machine to call hooks before or after it processes specific events.

These hooks are configured by calling overloads and variants of the following functions:

• maki::machine_conf::pre_processing_hook_v();
• maki::machine_conf::post_processing_hook_mep().

The pre hook is useful when you need to define a reaction to an event that is independent from the active states. For example:

    // Always log alerts
    .pre_processing_hook_e<alert_event>([](const alert_event& evt)
    {
        log_warning("Alert! ", evt.reason);
    })

The post hook can be used to handle the case where an event hasn't triggered any transition (neither external nor local). For example:

    // Notify client when reboot request is rejected
    .post_processing_hook_mep<client_reboot_request>([](
        auto& mach,
        const client_reboot_request& event,
        const bool processed)
    {
        if (!processed)
        {
            mach.context().server.send_to(
                event.client_id,
                "Can't reboot right now");
        }
    })

You can add as many hook as you want for different event types or event type sets.