Comparing the last releases of BC show, that the source code of the base app will be based on 2/3 EventPublisher and handle logic in near future.
It would be great, if a new attribute will be implemented that automatically creates an OnBeforeSomething, OnAfterSomething and OnSomething(..., Handled) with Handle pattern.

Example:
codeunit 50000 MyEventPublisher
{
// First true = OnBefore, second = On, third = OnAfter
[PublishEvents(true, true, true)]
local procedure MyFunction(SalesHeader: Record "Sales Header"; var ItemJnlLine: Record "Item Journal Line"): Boolean
begin
// my code
end;
}

Now all three events are generated from BC and can be used:
codeunit 50001 MyEventSubscriber
{
[EventSubscriber(ObjectType::Codeunit, Codeunit::MyEventPublisher, 'OnBeforeMyFunction', '', true, true)]
local procedure OnBeforeMyFunction(var SalesHeader: Record "Sales Header"; var ItemJnlLine: Record "Item Journal Line")
begin
end;

[EventSubscriber(ObjectType::Codeunit, Codeunit::MyEventPublisher, 'OnAfterMyFunction', '', true, true)]
local procedure OnAfterMyFunction(var SalesHeader: Record "Sales Header"; var ItemJnlLine: Record "Item Journal Line", var Result: Boolean)
begin
end;

[EventSubscriber(ObjectType::Codeunit, Codeunit::MyEventPublisher, 'OnMyFunction', '', true, true)]
local procedure OnMyFunction(var SalesHeader: Record "Sales Header"; var ItemJnlLine: Record "Item Journal Line", var Result: Boolean, var Handled: Boolean)
begin
end;
}