How to transfer a structure from one Plone to anot

Question

I have a Plone instance which contains some structures which I need to copy to a new Plone instance (but much more which should not be copied). Those structures are document trees ("books" of Archetypes folders and documents) which use resources (e.g. images and animations, by UID) outside those trees (in a separate structure which of course contains lots of resources not needed by the ones which need to be copied).

I tried already to copy the whole data and delete the unneeded parts, but this takes very (!) long, so I'm looking for a better way.

Thus, the idea is to traverse my little forest of document trees and transfer them and the resources they need (sparsely rebuilding that separate structure) to the new Plone instance. I have full access to both of them.

Is there a suggested way to accomplish this? Or should I export all of them, including the resources structure, and delete all unneeded stuff afterwards?

Answer 1

I recommend jsonmigrator - which is a twist on collective.transmogrifier mentioned by Godefroid. See my blog on it here You can even use it to migrate from Archetypes to Dexterity types (you just need matching fieldnames (and matching types roughly speaking).

Trying to select the resources to import will be tricky though. Perhaps you can find a way to iterate through your document trees & "touch" (in a unix sense) any resource that you are using. Then copy across only resources whose "timestamp" indicates that they have been touched.

Answer 2

I found out that each time that I make this type of migration by hand, I make mistakes that force me to do it again.

OTOH, if migration is automated, I can run it, find out what I did wrong, fix the migration, and do it all over again until I am satisfied.

In this context, to automate your migration, I advise you to look at collective.transmogrifrier.