Moving from OnCompanyOpen
APPLIES TO: Business Central 2022 release wave 1 and later
Your AL code might have to rely on an event to run immediately after a user signs in, and the OnAfterLogin event is the right one for the job in many cases. With the introduction of isolated events, it's possible to write events that don't stop executing when errors occur in their event subscribers. OnAfterLogin is such an isolated event. Subscribing to the OnAfterLogin event helps make sure users aren't prevented from signing in to Business Central because of a failed event subscriber.
About the OnAfterLogin and OnCompanyOpenCompleted events
The base application subscribes to a platform-based event, OnCompanyOpenCompleted, that is also an isolated event, and raises OnAfterLogin. We recommend that you subscribe to OnAfterLogin in your code, and that you do not subscribe directly to the platform-based event.
The OnAfterLogin and OnCompanyOpenCompleted events are both designed to replace the OnCompanyOpen event, which is obsolete and will eventually be removed. The application event subscribes to the platform event, so they are both raised during sign-in when Business Central tries to open the relevant company.
With the now obsolete OnCompanyOpen event, a failure in any event subscriber will stop the sign-in process. This behavior can be problematic for a couple reasons. There may be several subscribers from various extensions, and failures don't necessarily justify preventing the user from signing in. With the OnAfterLogin event, and it's sibling platform-based event, the sign-in process continues even though an event subscriber fails.
Move to the OnAfterLogin event
We recommend subscribing to the OnAfterLogin event instead of the OnCompanyOpen event, or even the OnCompanyOpenCompleted event, especially when developing for Business Central online. The OnAfterLogin event is published by the System Initialization module in the system application. In general, we recommend that you subscribe to events from the system application rather than directly from the underlying platform.
Moving from the OnCompanyOpen event to OnAfterLogin is as easy as changing the event subscriber definition. For example, change:
[EventSubscriber(ObjectType::Codeunit, Codeunit::"Company Triggers", 'OnCompanyOpen', '', false, false)]
to:
[EventSubscriber(ObjectType::Codeunit, Codeunit::"System Initialization", 'OnAfterLogin', '', false, false)]
Note
Events that are emitted from within the OnCompanyOpen event will eventually be moved to the the OnAfterLogin event or the OnCompanyOpenCompleted event, or they'll be changed to isolated events.