Fundamental Misunderstanding of Archetypes & Dexterity?

"Archetypes will remain available through the Plone 5 series" [1]

What does "available" mean exactly? Will my Archetypes-based custom content types still work (add/edit/view) in Plone 5?

Some of my custom content types inherit from ATContentTypes; for example, I have "class SpecimenFolder(folder.ATFolder)". Is this thing no longer viable?

If I create an empty Plone site with that same "SpecimenFolder" add-on, suddenly the "createObject" link for SpecimenFolders is a 404. Am I doing something wrong or should I re-write "class SpecimenFolder" to be "class ISpecimenFolder" Dexterity-style? And if so, how do I migrate existing SpecimenFolders in a site to this new custom type?

Sorry for the confusion.


Plone 5.2 (currently in alpha) is going to run on both Python 3 and Python 2. Archetypes is not going to be upgraded to work on Python 3, so if you still need to use Archetypes in Plone 5.2, you'll need to run it with Python 2.7.

The migration from Archetypes to Dexterity can be done multiple ways:

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Chrissy did a good job summarizing your options for migration.

In addition: If you create a site on Plone 5.2 (still on Python 2) and install ATContentTypes as an add-on before installing your add-on that uses Archetypes, there's a decent chance it will work. The core team isn't actively trying to break Archetypes support and has gone to some lengths to make sure the tests keep passing in Plone 5.2 (for Python 2 only). But, it's no longer the focus of the core team, and it's unlikely that support will be continued beyond Plone 5 or that the core team will port it to Python 3.

The official story for integrators and customers is that no production environment should run on Python 2.7 after 1.1.2020...while this is not going to happen in general, the general advice is to get rid Archetypes-based code and add-ons in Plone 5 projects asap. This also means the death of fancy add-ons like PloneFormGen.


As RHEL 8 recently committed to the upkeep of Python 2.7, it'll not really die off too soon, even if the upstream proper stops upkeeping it.

And it seems I've misinterpreted this one - upon a reread it seems they only state they still offer it during the beta phase.