Directory config import shouldn't erase content

A somewhat related problem is the current inability of extension profiles to erase an existing directory to transtype it.

Suppose I want to build an extension profile that replaces the members directory with a new meta directory with a bunch of backings for instance. At import time, the importer will try to reconfigure the existing members ZODBDirectory of the base profile with the configuration for the StackingDirectory? as defined in the extension profile.

Maybe the importers should check the meta_types and purge the existing objects if the meta types do not match.

This transtype feature would be interestingly upgraded once we have directory content ex/importers that could dump the directory content on a temporary file, transtype and reconfigure the directory and reupload the content back to the new dir.

Otherwise, we should make it possible to explicitely purge the directory tool from an extension profile (with a 'purge="True"' attribute for instance).

If you believe both problems are not related enough, tell me and I'll open a dedicated ticket.

s/Stacking/Meta/g

The directory content is not removed anymore on profile import: [32681]. For now, only the ZODBDirectory benefit from this.

TODO: expand the behaviour to other directory types.

Are there other directories which can be called Contentish (besides ZODBDirectory)?

Also, about the transtyping, this will be taken care in #1378

Only ZODBDirectory is Contentish, all other directories store data in external systems that don't need to be backed up.

Then this could be closed