An installation without a configured database should be a supported feature

[albe]

Currently, if no database is configured, a whole lot of things don't work out correctly because there are a bunch of places that just assume a datbase is configured and available.

It should be possible to run a Flow installation completely without any database configured. Only if features that inevitably require a database, like Entities, are used, Flow should error out.

Some places that currently use the persistence layer to some extent (not necessarily failing without configured database):

• Routing
• forwarding to another action inside a Controller
• Resources
• some ViewHelpers use getIdentifierByObject() calls (though that works generally, it is pretty expensive if it is clear upfront that the object is not an entity)
• Authentication with PersistedUsernamePasswordProvider (obviously)

Not sure how to best approach this best, but I could imagine doing some compile-time check if a database is configured and store that information accessibly. If not switch to a mode that avoids using persistence layer where possible and fails with a clear message where not (for example when persistenceManager->persistAll() is called - see #1037).

[sorenmalling]

My ticket is sort of related to this For reference: #1077