Sally Kleinfeldt's summary of Plone Web services discussions at the Plone Strategic Planning Summit and the 2008 Plone Conference.

1. Plone Web Services
2008 Plone Conference
Sally Kleinfeldt, Jazkarta

2. 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)

3. 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

4. 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

5. 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

6. 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

7. 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)

8. 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

9. 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...”

10. 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

11. 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!

12. 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
(quot;browser webquot;), and WebDAV

13. 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

14. 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

15. 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

16. 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!)