Plone Web Services
2008 Plone Conference
Sally Kleinfeldt, Jazkarta

Background
• Plone’s current web services story is
restricted to XMLRPC and RSS
• Becoming a glaring omission
• Plone Strategic Planning Summit voted it a
focus area
• Support an official and complete web
services API (REST)

Previous Work
• CIGNEX implemented SOAP web services
on Archetypes for a customer
• z3c.rest provides a framework to build
REST APIs on top of Zope 3
• Grok provides REST web services support
• Vice provides Atom syndication
• Boston and Naples sprints on RESTful WS

PSPS Project
• Ticket (includes link to plone-dev posts):
http://dev.plone.org/plone/ticket/7842
• OpenPlans Page: http://www.openplans.org/
projects/plone-web-services/project-home

Proposed Approaches
• Custom XML schemas for serializing
content objects (building on GenericSetup)
• Microformats
• Atom Publishing Protocol possibly with
GData extensions for search
• OpenSocial for Plone (JavaScript and Atom)
• Use OAuth for authentication

Recent News
• New “draft standard” announced Sept 10
• CMIS - Content Management
Interoperability Services
• EMC, IBM, Microsoft, Alfresco, Open Text,
Oracle, SAP, and others
• Draft specification for a web services
standard for content management

CMIS
• Has SOAP and REST bindings
• REST binding defined as extension to Atom
but tightly coupled to data model with
“protocol extensions that tunnel the Web
Services interface through fake-Atom and
fake-HTTP” (Roy Fielding)
• Has hype, buzz and industry support (try a
Google search and see EMC, Alfresco ads)

CMIS REST:
Is It Any Good?
• Roy Fielding
• “I am getting tired of big companies
making idiotic claims about REST and
their so-called RESTful architectures. The
only similarity between CMIS and REST is
that they both have four-letter acronyms”
• http://roy.gbiv.com/untangled/2008/no-
rest-in-cmis

CMIS REST:
Is It Any Good?
• Roy Fielding con’t
• “...unless you expect blogging clients and
syndication feeds to be the primary
application of CMIS, it would make a lot
more sense to define the representations
in a microformat of HTML, JSON,YAML,
or whatever else best fits the data...”

CMIS REST:
Is It Any Good?
• Sam Ruby
• Cautiously optimistic
• Feels OASIS TC will address problems
• http://www.intertwingly.net/blog/
2008/10/01/CMIS

Questions
• Should Plone adopt CMIS? or CMIS REST?
• No, reconsider when/if a “standard”
• Should Plone adopt microformats instead?
• Not systematically, just a view so easy to
add for specific cases
• Should Plone adopt AtomPub?
• YES!

Technical Approach
• Existing Python AtomPub server packages
include Amplee and FlatAtomPub
• Plone today isn't a good fit for REST style
services because the Zope2 publisher
ONLY does FTP, HTTP GET/POST
(\"browser web\"), and WebDAV

AtomPub WSGI App?
• Idea: Atom Publishing application living in a
Repoze ecosystem
• Aggregate content from several Plone,
Grok, etc. sites
• Get around the lack of PUT/DELETE in
Plone - act as a middleman
• Use zgeo.atom as starting point

Atom For Now
• Focus on providing read-only Atom
representations
• Atom browser view that would apply to
any folderish object
• Start at the root of the Plone site and
discover all the Atom publishable objects by
following the Atom links

Syndication vs. Web
Services
• Syndication view: content owners would
need to explicitly declare folders as feeds
• All-inclusive view: all content should
provide the AtomPub interface

Conclusion
• Implementing RESTful web services will be
a large and complex project, given the
limitations of the Zope2 publisher
• Not realistic to expect it to get done in a
sprint or even a series of sprints
• Most likely scenario: a customer needing
support for CMIS (after all!)