Architecture: packages and dependencies

Architecture: packages and dependencies#

This chapter describes the architecture of Plone's packages and dependencies.

Motivation#

Over the years, Plone has developed many indirections in its packages and dependencies. The goal in the long run is to untangle them and get a simple dependency graph. This document shows the current state, as an orientation to its architecture.

Overview#

There are multiple level of dependencies:

  • package level (setup.py/setup.cfg/pyproject.toml)

  • Python level (imports)

  • ZCML level (includes)

  • testing (need for layers, such as functional testing)

Circular dependencies at the package level have now been resolved. Nevertheless, there is indirection on all other levels. Since Plone consists of a lot of packages, it is complex to untangle those.

Mental model#

This section describes a mental model that organizes Plone 6.1 packages into three groups separated by two packages that define the borders between these groups.

Borders#

In Plone 6.1, there are two packages that serve as dividing lines.

  1. Products.CMFPlone and all packages below it define the Plone core. Everything in here depends on the plone.base.

  2. plone.base is the border between the Application Server and Content Management Framework (CMF) with its dependencies.

        block-beta
    columns 4
    Plone["Plone<br/>integraton of all in one release"]:4
    Distributions
    Upgrade
    coreapis["Core APIs"]
    coreaddons["Core add-ons"]
    cmfplone["Products.CMFPlone"]:4
    ploneapp["Most of plone.app.* namespace"]:2
    otherlay["Various related packages"]:2
    plonebase["plone.base"]:4
    block:groupfoundation:4
        zopecore["Zope core/ ZCA"]
        zopeeco["Zope ecosystem"]
        cmfcore["CMFCore"]
        ploneworld["Plone generic libraries"]
        libraries["Other libraries"]
    end  
    style cmfplone fill:#fff9e6
    style plonebase fill:#fff9e6

Mental model of Plone#

Main components#

The following points describe the mental model.

  • Foundation:

    • Zope core and its dependencies is the application server,

    • the Zope component architecture (ZCA) framework and

    • some additional packages from the wider Zope ecosystem.

    • Then there are generic, standalone Plone libraries,

    • plus various other Python libraries.

  • Products.CMFCore provides very basic content management features on top of Zope on which Plone relies.

  • plone.base defines several interfaces as contracts for the component architecture on which Plone is built. Additionally, it provides some base classes and utility functions that Plone often uses. It also depends on Products.CMFCore, and therefore Zope. Additionally, it depends on generic functionality provided by plone.dexterity, plone.behavior, and plone.registry.

  • The space of many plone.*, plone.app.*, and their related libraries defines the core of Plone.

  • On top of this core, depending on these packages, is Products.CMFPlone, which is the package to depend on if the basic Plone core is referenced.

  • On top of Products.CMFPlone are the following.

    • The core APIs plone.api and plone.restapi.

    • There is distribution support in plone.distribution and specific distributions, currently plone.volto and plone.classicui.

    • Core add-ons include Working Copy Support from plone.app.iterate, discussion support (plone.app.discussion), and other add-ons.

    • plone.app.upgrade is the package to upgrade between Plone versions.

  • If you want to depend on the whole Plone with everything, you should depend on the package Plone. This meta package without any code depends on all other packages. It is what you want to install if you don't care about the details and get "batteries included".

The space on top of Products.CMFPlone#

Add-on developers and integrators primarily interact with the dependencies on top of Products.CMFPlone. The following diagram visualizes this part. You can zoom in on the diagram.

        ---
config:
  sankey:
    height: 800
    nodeAlignment: right
    showValues: false
    width: 1600

---
sankey-beta

    Plone,Distributions,100

    Distributions,plone.volto,50
    Distributions,plone.classicui,30
    Distributions,other dist.,20



    plone.volto,plone.distribution,10
    plone.volto,plone.restapi,20
    plone.volto,plone.api,20

    Multlilingual,plone.api,20
    Commenting,plone.api,20
    Working Copies,plone.api, 20
    Caching,plone.api,20

    plone.classicui,plone.distribution,15
    plone.classicui,plone.api,15
    other dist.,plone.distribution,4
    other dist.,plone.api,8
    other dist.,plone.restapi,8


    Plone,Core-Addons,80

    Core-Addons,Multlilingual,20
    Core-Addons,Commenting,20
    Core-Addons,Working Copies,20
    Core-Addons,Caching,20

    plone.distribution,Export/Import,15
    plone.distribution,plone.api,14
    plone.restapi,Core,20
    Export/Import,plone.api,8
    plone.restapi,plone.api,15
    Export/Import,plone.restapi,7
    Upgrade,Core,20
    plone.api,Core,160

    Plone,Upgrade,20

Diagram of the space on top of Products.CMFPlone#

Detailed view of the architecture#

The following diagram provides a more detailed view of the whole architecture of Plone. You can zoom in on the diagram.

        ---
config:
  darkMode: 'true'
  theme: base

---
%%{
  init: {
    'theme': 'base',
    'themeVariables': {
      'primaryColor': '#fefefe',
      'lineColor': '#aaa'
    }
  }
}%%

flowchart TB
 subgraph Release["Release"]
        Plone[["'Plone' Package"]]
  end
 subgraph subGraph1["Distributions"]
        volto{{"plone.volto"}}
        classicui{{"plone.classicui"}}
        other{{"other ..."}}
  end
 subgraph Core-Addons["Core-Addons"]
        multilingual("Multilingual")
        iterate("Working Copies")
        discussion("Commenting")
        caching("Caching")
  end
 subgraph API["API"]
        restapi("RestAPI")
        ploneapi("API")
        upgrade("Upgrade")
        exportimport("Export/Import")
        distribution["Distribution"]
  end
 subgraph subGraph4["The Inner Core"]
        thecore((("Core-Features: plone.*, ...")))
  end
 subgraph Core["Core"]
        cmfplone["Products.CMFPlone"]
        plonebase["plone.base"]
        subGraph4
  end
 subgraph Foundations["Foundations"]
        zope["Zope/CMF/ZODB/..."]
        supportlibs["Several Supporting Libraries"]
  end
    Plone == provides ==> volto
    Plone -. provides .-> classicui & other & upgrade & multilingual & iterate & discussion & caching
    volto -- installs --> restapi
    volto == is a ==> distribution
    classicui -. is a .-> distribution
    other -. is a .-> distribution
    distribution -- uses --> exportimport
    distribution == depends on ==> ploneapi
    restapi -- depends on --> ploneapi
    cmfplone == depends on ==> thecore
    thecore == depends on ==> plonebase
    plonebase == depends on ==> zope
    plonebase -- depends on --> supportlibs
    zope -- depends on --> supportlibs
    ploneapi == depends on ==> cmfplone
    upgrade -- depends on --> cmfplone
    multilingual -- depends on --> ploneapi
    iterate -- depends on --> ploneapi
    discussion -- depends on --> ploneapi
    caching -- depends on --> ploneapi
    exportimport -- uses serializers of --> restapi
    exportimport -- depends on --> ploneapi

Architecture of Plone#

Packages in detail#

Looking deeper into those packages, there are more subdivisions which fall into three groups.

Above Products.CMFPlone#

  • Plone

  • plone.api

  • plone.app.iterate

  • plone.app.upgrade

  • plone.restapi

  • plone.volto

  • Products.CMFPlacefulWorkflow

Between Products.CMFPlone and plone.base#

  • collective.monkeypatcher

  • plone.app.caching

  • plone.app.content

  • plone.app.contentlisting

  • plone.app.contentmenu

  • plone.app.contentrules

  • plone.app.contenttypes

  • plone.app.customerize

  • plone.app.dexterity

  • plone.app.discussion

  • plone.app.event

  • plone.app.i18n

  • plone.app.intid

  • plone.app.layout

  • plone.app.linkintegrity

  • plone.app.locales

  • plone.app.lockingbehavior

  • plone.app.multilingual

  • plone.app.portlets

  • plone.app.querystring

  • plone.app.redirector

  • plone.app.registry

  • plone.app.relationfield

  • plone.app.textfield

  • plone.app.theming

  • plone.app.users

  • plone.app.uuid

  • plone.app.versioningbehavior

  • plone.app.viewletmanager

  • plone.app.vocabularies

  • plone.app.widgets

  • plone.app.workflow

  • plone.app.z3cform

  • plone.browserlayer

  • plone.cachepurging

  • plone.contentrules

  • plone.formwidget.namedfile

  • plone.formwidget.recurrence

  • plone.i18n

  • plone.namedfile

  • plone.outputfilters

  • plone.portlet.collection

  • plone.portlet.static

  • plone.portlets

  • plone.protect

  • plone.resourceeditor

  • plone.rfc822

  • plone.schemaeditor

  • plone.session

  • plone.staticresources

  • plone.stringinterp

  • plone.theme

  • plonetheme.barceloneta

  • Products.isurlinportal

The foundation below plone.base#

Plone world#

  • borg.localrole

  • plone.alterego

  • plone.autoform

  • plone.autoinclude

  • plone.batching

  • plone.behavior

  • plone.caching

  • plone.dexterity

  • plone.event

  • plone.folder

  • plone.indexer

  • plone.intelligenttext

  • plone.keyring

  • plone.locking

  • plone.memoize

  • plone.registry

  • plone.resource

  • plone.rest

  • plone.scale

  • plone.schema

  • plone.subrequest

  • plone.supermodel

  • plone.transformchain

  • plone.uuid

  • plone.z3cform

  • Products.DateRecurringIndex

  • Products.ExtendedPathIndex

  • Products.MimetypesRegistry

  • Products.PlonePAS

  • Products.PortalTransforms

  • Products.statusmessages

Zope ecosystem#

  • Chameleon

  • diazo

  • five.customerize

  • five.intid

  • five.localsitemanager

  • icalendar

  • Products.CMFCore

  • Products.CMFDiffTool

  • Products.CMFDynamicViewFTI

  • Products.CMFEditions

  • Products.CMFUid

  • Products.DCWorkflow

  • Products.ExternalMethod

  • Products.GenericSetup

  • Products.MailHost

  • Products.PluggableAuthService

  • Products.PluginRegistry

  • Products.PythonScripts

  • Products.Sessions

  • Products.SiteErrorLog

  • Products.StandardCacheManagers

  • Products.ZopeVersionControl

  • repoze.xmliter

  • webresource

  • z3c.caching

  • z3c.form

  • z3c.formwidget.query

  • z3c.objpath

  • z3c.pt

  • z3c.relationfield

  • z3c.zcmlhook

  • zc.recipe.egg

  • zc.relation

  • zodbverify

  • zope.copy

  • zope.intid

  • zope.keyreference

Zope core#

  • AccessControl

  • Acquisition

  • AuthEncoding

  • beautifulsoup4

  • BTrees

  • DateTime

  • DocumentTemplate

  • ExtensionClass

  • Missing

  • MultiMapping

  • Persistence

  • persistent

  • Products.BTreeFolder2

  • Products.ZCatalog

  • Record

  • RestrictedPython

  • transaction

  • zc.lockfile

  • ZConfig

  • zdaemon

  • ZEO

  • zExceptions

  • ZODB

  • ZODB3

  • zodbpickle

  • Zope

  • zope.annotation

  • zope.app.locales

  • zope.browser

  • zope.browsermenu

  • zope.browserpage

  • zope.browserresource

  • zope.cachedescriptors

  • zope.component

  • zope.componentvocabulary

  • zope.configuration

  • zope.container

  • zope.contentprovider

  • zope.contenttype

  • zope.datetime

  • zope.deferredimport

  • zope.deprecation

  • zope.dottedname

  • zope.event

  • zope.exceptions

  • zope.filerepresentation

  • zope.globalrequest

  • zope.hookable

  • zope.i18n

  • zope.i18nmessageid

  • zope.interface

  • zope.lifecycleevent

  • zope.location

  • zope.pagetemplate

  • zope.processlifetime

  • zope.proxy

  • zope.ptresource

  • zope.publisher

  • zope.ramcache

  • zope.schema

  • zope.security

  • zope.sendmail

  • zope.sequencesort

  • zope.site

  • zope.size

  • zope.structuredtext

  • zope.tal

  • zope.tales

  • zope.testbrowser

  • zope.testing

  • zope.traversing

  • zope.viewlet

  • Zope2

Libraries#

  • attrs

  • cffi

  • cssselect

  • decorator

  • docutils

  • feedparser

  • future

  • importlib_metadata

  • jsonschema

  • Markdown

  • multipart

  • Paste

  • PasteDeploy

  • piexif

  • Pillow

  • pycparser

  • PyJWT

  • pyrsistent

  • python_dotenv

  • python_gettext

  • requests

  • roman

  • sgmllib3k

  • simplejson

  • soupsieve

  • Unidecode

  • urllib3

  • waitress

  • WebOb

  • WebTest

  • WSGIProxy2

  • zipp

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