Restrictive plugin

Hello guys,

I'm trying to create a plugin that prevent remove of a specific domain no matter what happen

Basically the plugin lookks like that :

PHP:

class admin_restriction_plugin {

     var $plugin_name = 'admin_restriction_plugin';
     var $class_name = 'admin_restriction_plugin';
    
     function onLoad() {
         global $app;

         $app->plugin->registerEvent('mail:mail_domain:on_before_delete', 'admin_restriction_plugin', 'before_mail_domain_delete');
         $app->plugin->registerEvent('dns:dns_soa:on_before_delete', 'admin_restriction_plugin', 'before_dns_soa_delete');
     }
    
    function before_mail_domain_delete($event_name, $page_form){
        global $app, $conf;   
        
        if(in_array($page_form->dataRecord['domain'], $conf['domain_deletion_restriction'])  )
        {
            $app->error('Opération non permise / Operation not allowed', '', true, 1);
        }   
    }
    

    function before_dns_soa_delete($event_name, $page_form){
        global $app, $conf;   
        
        $origin = rtrim($page_form->dataRecord['origin'], ".") ; // trailling dot not needed
        
        if(in_array($origin, $conf['domain_deletion_restriction'])  )
        {
            $app->error('Opération non permise / Operation not allowed', '', true, 1);
        }   
        
        // Records inside the zone are deleted ... not good
    }
    
}

Problems:

1. Records inside a DNS zone are deleted but not the zone itself...
   • We need to preserved the records inside the zone AND the zone
2. The same happens for a mail domain.
   • We need to preserve mailbox, alias, forward ...

Is it possible ?
Any idea how can I do that ?

Regards,
Cédric