Is Volto compatible with Guillotina? Not 100 percent. Question is how we keep the APIs in sync. If people figure out a shared generic API that works with both Plone and Guillotina as backend, this can work.

How do you migrate? You can migrate from Plone 4.3 to Volto. We did that with transmogrifier. Biggest problem is moving composite pages, like cover, to the Volto blocks. In a post migration step, you can fix things up.

Why Semantic UI? Rob researched all the popular ones, concentrating on how easy it is to theme or override stuff. Semantic UI makes this easy. You derive from a theme, and only override some parts.

For add-ons, how do you keep the backend part in sync with the frontent part? You don't. You use Python packages in the backend and node packages in the frontend. There will probably be a lot of packages that are only in the backend or only in the frontend. You may need to be careful in the frontend so that it can work with several versions of the backend of this add-on.

TypeScript has won the JavaScript wars. Will you support that? We don't want to support two ways of doing the same thing. So if we switch to TypeScript, we want to stop using ES6, also in the documentation. Same for class based versus function based.

Did you check accessibility? Yes. We have a static code checker ALM that helped us fix issues. Also the Cyprus tool. But we also do manual checks. Plone Foundation is trying to get funding for an audit.

Frontend is nice, but it needs a backend, so let's talk about that. I will talk about plonecli, plone.api, Plone snippets for VS Code and plone.restapi.

You should use plonecli. It saves a lot of time for boring stuff. It helps you to create a product and enhance it step by step. It can cleanup and create a fresh virtualenv with a specific Python version and requirements and run buildout.

It has sub templates, for example to add a content type to your package. Now a sub template for a restapi service. Also one for upgrade steps, adding an upgrade profile per upgrade step.

We create a structure and files, and if you don't use some parts you can ignore or remove them. We will check if you have a clean git status before, and ask to commit, and afterwards we automatically commit.

You have good test coverage right from the start. All features added by plonecli have at least basic test coverage. You only write the tests for your own code. We make a tox environment to test different Plone and Python versions.

You can configure plonecli/mr.bob to your taste, changing the default answers or ignoring questions in a .mrbob file.

It is extensible, you can write your own custom bobtemplate packages and register them for the plonecli.

Visual Studio Code: snippets for Plone

There are snippets for schemas, fields, registry xml.

Use plone.api. It makes add-on code much easier to understand, without arcane incantations.

Ideas for the future.

• plonecli:
  • add option to set Interface for view, viewlet.
  • REST API sub templates for de/serializer.
  • Graphical UI (ncurses-like) to make selecting options easier.
• VS Code: plone.api autocompletion. VS Code is not so smart with namespaces. And it does not know buildout. You can use a buildout recipe that helps here though. Or use the generated zopepy script as your Python.

I would love more contributions. Don't be shy. There is no grand jury who makes decisions. Publish your own bobtemplates. Improve the VS Code snippets, or for other editors. Meet me at the sprints.

Question: is there a bobtemplate to create a new bobtemplate?

Answer: No. Should be possible.

https://ugent.be is a Plone 4.3 site of a large Belgian university. Started in 2002 as Zope/CMF site. 90.000 pages, sub sites, 40.000 students, hundreds of editors, 90 add-ons. They wanted to move to Plone 5.2 and Python 3.

• Traditional in-place migration: too manu add-ons, no one-on-one mapping possible.
• Transmogrifier: not yet Python 3 at the time, too much magic hidden in too many places with blueprints.
• So: custom migration solution.

Content types: standard types, plus four custom content types, including PloneFormGen. So that is quite reasonable. There is extensive usage of archetypes schema extenders.

Start: analyze and investigate your dependencies. - Based on Archetypes? Obsolete, replace. - No longer needed? Remove it. In Confluence we compiled a big table with for each package the basic information of how we would handle it: upgrade it, replace it, unknown yet, status of Python support.

Start with a minimal Plone 5.2 setup. Add one verified Python 3 compatible add-on at a time. Test extensively. Focus on content types first. Things like portlets can be handled later.

You need an export. We used a customized version of collective.jsonify. Core numbers: 90.000 json files, 55 GB data, 90 minutes, binary files base64 encoded.

We exported portlet assignments, default pages, layout information, workflow state, local roles, and pre-computed values for further efficient processing.

So we had 90.000 json files on the file system. We imported this in ArangoDB. Why use such a migration database? This allowed us to import only some portal types, or do parallel imports, and test complex migration steps like for PloneFormGen.

We briefly tried MongoDB, but that could not handle data over 16 MB. The json could be dumped unchanged in ArangoDB. This took 45 minutes.

Now we need to import this into Plone. Clean Python 3.7, Plone 5.2, plus the minimal set of packages needed for the content types. Import via plone.restapi. On top we have a dedicated migration package with special views. This handled things like translating between UIDs and paths.

The "magic" migration script is based on configuration in YAML.

• Phase 1: pre-check the migration, remove target site if it already exists from previous test, create new Plone Site, install add-ons.
• Phase 2: create all Folders, query ArangoDB for this.
• Phase 3: create all non folders.
• Phase 4: global actions. Check and migrate paths to UIDs in rich text fields. Assign portlets. Other specific fixup operations, like reindexing.

We migrated PloneFormGen (Archetypes) to easyform (dexterity). Export: one JSON for the FormFolder, one JSON file per field and action adapter. In easyform this needed to be turned into an EasyForm instance and a schema.

Topics (AT) to Collections (dexterity). Code was largely taken over from the plone.app.contenttypes migration.

From AT schema extenders to dexterity behaviors. First we made a list of which there were, are they in use, what do they do? Check which dexterity replacements there are. Create new behaviors.

Migrate packages to Python 3. This is mostly covered by talks of Philipp Bauer and David Glick. Common problems: utf-8 versus unicode, import fixes, implements to implementer. I rarely used the 2to3 and modernizr tools.

Some reimplementations: - portal skins to browser views - some packages with AT replaced with new packages with dexterity

Other problems:

• improper file and image metadata
• migration of vocabulary values, like old to new departments
• repetitive cycles: always a bug occurs after a day of migration right before the end.

Quality control: - you need to check that migrated content and configuration is complete - "works for me" is nice, but others need to check too

Most of the packages have been removed, the setup is much smaller.

Status: - content migration is complete - must be tested in detail - integrate with the new theme, test this - need a replacement of a specific membrane usage - need work on castle/cas plugin

Takeaways: - Export Plone to JSOJN: 2 hours. Fast. - Import JSON to ArangoDB: 45 minutes. Fast. - Import ArangoDB to plone.restapi: 36-48 hours. Painfully slow. - 1.5 - 2.0 seconds per content object on average - cannot parellellize this import, because you would get conflict errors - So Plone and ZODB and painfully slow for creating mass content.

Question: in a similar setup we did a live migration from a live site to a separate new site. Did you consider that?

Answer: I tried this for other sites, but here I wanted to be able to partial imports, independent of the live site.

Question: default migration patches away all kinds of expensive indexing. You might want to consider looking at that. Migrating ten items per second is possible, although that is inline migration. And can you share the code, especially for the easyform migration?

Answer: could be done, but is not the primary focus of the budget currently.

A slightly older version of the code is on community.plone.org.

Gatsby Preview gives you hot reloading of content. So you change something in Plone CMS, and it immediately is visible on your Gatsby site.

Plone CMS -> Web hook -> Gatsby source plugin. When content is created, edited, deleted, we will fire a websocket event.

When you change the title of a folder, you should update the breadcrumbs of the children too, and also navigation in several places. It took me a long time, but I have implemented this.

I have created a Gatsby theme for Plone: https://github.com/collective/gatsby-theme-plone