In the 15 minute twitter video, Chris broadcasts the updated Post event with the entity attached which is then simply appended to the list of Posts. This is a simple operation but it does create a little bit of duplication with the domain code—a Post is added to the conceptual list of Posts in the db, then to the literal list of Posts in the LiveView state. This duplication can get a lot hairier in more complicated scenarios, though. For example, when moving an item from list to another, there are three entities involved: the item along with the source list and destination list. This would result in having to the write that logic in both the view and the domain layers.

Is this generally the route people take? Is it viable to have a view model (or data helper) pre-emptively update the state then sending the result to the db? Is there any disadvantage to that assuming you could blow up on the db update if it fails which would re-render the LiveView in the previous state?

I would love to get some feedback with different ideas on this!

Thanks!