If we would start from scratch with what we know now, how would Joomla! look like. From a developers/architectural point of view. Focus on Domain Driven Design.

1. Joomla! 2.0 Architecture
J and Beyond
May 6, 2011
Herman Peeren
www.yepr.eu
herman@yepr.nl
Filip Dujardin: Crazy Building 6

2. Software Architecture
• structure of the whole
• under the hood

3. Extending what you have...
starting small:
building more
• more and more
• knitting...
• more
• and more
• and even more
James Wines: Highrise of Homes (1981)

4. and more...
Hundertwasser

5. Until the past becomes a burden
Giovanni Francesco Barbieri Guercino: Atlas (1646)

6. Example: Joomla! 1.6 ACL
• earlier Access Control for editing: /administrator-folder
• earlier Access Control for viewing: restricting menu- and article ac-
cess for groups
• newer ACL while keeping the old structures

7. After:
• 1.5
• 1.6
• 1.7
• 1.8
• 1.9
• 1.10
• ...
• 1.98
...it might be time for a
Major release: .
N.B.: no major version forseen in framework version numbers (11.1 etc.)

8. Not even the sky is the limit!
Andrea Pozzo: trompe l’oeil, fresco, St. Ignazio, Roma

9. some books:
both from 2003...

10. Conversion
to
OOP
DDD
ORM
TDD
COC
WTF
Caravagio: the Conversion of St. Paul (1601)

11. Back to the OOP-basics
• Simula (1960s); e.g. simulation of waiting queues
• no division between data and behaviour: objects!
• smaller problems that can be handled
Nelleke Verhoeff: Ellenlange Schlange (2003)

12. Layers
• 3 main layers:
presentation,
domain,
data
• OOP: domain layer
is central (DDD)
Mark Rothko

15. ORM
• Object - Relational Mapping
• Frameworks. Java: Hibernate. PHP: Doctrine (2)
• Doctrine a.o. used in Zend, Symfony etc.
• Can be used in Joomla! (JCM-article)
• http://www.doctrine-project.org

16. aside: LINQ... for PHP
• SQL for recordsets in .NET (Language Integrated Queries)
• PHP, open source: http://phplinq.codeplex.com/
• mainly targeting Recordsets (but could be generally useful for
Table Data Gateways)
• Doctrine uses DQL (like SQL, but querying objects, not tables)

17. MVC?
• How does our Holy Trinity MVC fit into this story?
Antonio de Pereda (1611-1678): Holy Trinity

18. MVC and layers
• invented 1978/1979
• originally in the presentation layer
• now: scattered over layers
• or: instead of layers
Prof. Trygve M. H. Reenskaug (Oslo)

19. ← MVC in presentation layer

20. MVC everywhere...

21. Naked Objects
• PhD thesis Richard Pawson
2004 (Dublin, Ireland)
• http://downloads.nakedobjects.net
/resources/Pawson%20thesis.pdf
• Foreword by Trygve Reenskaug
• back to
‘behaviourally-complete’ objects!
Hans Memling: Vienna Triptych Enthroned Madonna (1485), closed

22. NakedPHP
• a framework to implement Naked Objects in PHP
• by Giorgio Sironi
• http://giorgiosironi.blogspot.com/2009/07/naked-objects-in-php.html
• http://sourceforge.net/projects/nakedphp/ (LGPL)
Adolf Ziegler: The Four Elements: Fire, Water and Earth, Air (before 1937)

23. Experiments from the lab
• System-U: all objects only a uniform interface as public methods
• System-R: recources as basic objects
• System-A: Access control as feature in basic objects
• agregate MVC: class com_mycontents extends com_contents
Piet Mondriaan (1872-1944): tree, more and more abstract

24. Joomla! 2.0 could have:
• DDD and ORM
• database independency
• better integrated ACL, no /administrator
RESTful interface
...and be:
•
• Extendable API
UP
-TO
-D
AT
E!
Vangobot: Skyscrapers Architecture Pop (http://popartmachine.com/)

25. “Creativity
requires the courage
to let go certainties” Erich Fromm
Sergey Tyukanof (http://www.tyukanov.com/): Alice in Wonderland (2005)

26. Who joins this dance?
• goal: to work towards a new major version
Henri Matisse: La Danse (1910)