XCompose : An XML-based Component Composition Framework

1. XCompose:An XML-based Component Composition Framework Naiyana Tansalarak and Kajal T. ClaypoolUniversity of Massachusetts, Lowell July 22nd, 2003 In Workshop on Composition Languages (WCL) 2003 (conjunction with ECOOP 2003) Darmstadt, Germany

2. Introduction Component-based Software Systems • pre-fabricated components • composition framework Advantages: • on-time development • higher quality • higher reliability

3. Flexible- plug-and-play Re-usable - make compositions available to all users Correct - provide system-level guarantees Portable-enable composition across component models Goal of Composition Framework New requirement Asset Specification New technology Extensible - tailor existing compositions

4. Outline • Previous Work • Our Approach • Discussion

5. Piccola      BML/CoML      Flexibility Extensibility Reusability Correctness Portability Previous Work • Piccola application = components + script • Bean Markup Language (BML) • Component Markup Language (CoML) XCompose     

6. Hypothesis Complex Component Composition can be broken down into a sequence of a primitive composition operators glued together by a simple language

7. Paradigm Components Application = + Composition Language Operators Composition Language = + Glue Logic

8. Composition Operators Composition Templates Composition Contracts XDescriptors XCompose Basics Goals Ingredients New requirement Asset Specification New technology Flexibility Extensibility Reusability Correctness Portability Composition Patterns www.cs.uml.edu/~ntansala

9. Composition Operators Composition Templates Composition Contracts XDescriptors XCompose Basics Goals Ingredients New requirement Asset Specification New technology Flexibility Extensibility Reusability Correctness Portability Composition Patterns www.cs.uml.edu/~ntansala

10. Primitive Operators Primitive Composition Operators • Conjunction mi mj • Sequence mi; mj • Choice miV mj • Pipe mi| mj • Loop mi* V • Primitive Manipulation Operators: • addAttribute • addMethod • invokeMethod • addComponent

11. Complex Operators Complex Composition Operators • Connection-oriented Composition • addConnection • Aggregation-based Composition • addToContainer • Complex Manipulation Operators • configureProperty • addListener • addEvent • linkEvent

12. Composition Operators Composition Templates Composition Contracts XDescriptors XCompose Basics Goals Ingredients New requirement Asset Specification New technology Flexibility Extensibility Reusability Correctness Portability Composition Patterns www.cs.uml.edu/~ntansala

13. Composition Pattern A sequence of composition operators glued together by a simple language

14. ListMultiselector event(ListMultiselector) = event (GUIList) U event (Multiselector) Example : Composition Pattern ListMultiselector { addComponent(“java.awt.List”, “list”); addComponent (“java.awt.Multiselector”, “selector”); addToContainer(“list”, “selector”); linkEvent(“paint”, “list.paint”); linkEvent(“select”, “selector.select”); linkEvent(“deselect”, “selector.deselect”); linkEvent(“close”, “selector.close; list.close”); }

15. ListMultiselector FrameList event(ListMultiselector) = event (GUIList) U event (Multiselector) event(FrameList) = event (JFrame) U event (GUIList) Common Composition Pattern

16. Composition Operators Composition Templates Composition Contracts XDescriptors XCompose Basics Goals Ingredients New requirement Asset Specification New technology Flexibility Extensibility Reusability Correctness Portability Composition Patterns www.cs.uml.edu/~ntansala

17. Composition Pattern Template The parameterized and generalized composition patterns.

18. Example: Composition Template MergeMasterClient (master, client) { addComponent (“$master”, “container”); addComponent (“$client”, “part”); addToContainer (“container”, “part”); let $tmp = event (“container”) ∩ event(“part”) forall $eЄ event(“container”) and $e $tmp linkEvent (“$e”, “container.$e”); forall $eЄ event(“part”) and $e  $tmp linkEvent (“$e”, “part.$e”); forall $eЄ $tmp linkEvent (“$e”, “part.$e; container.$e”); } ListMultiselector { addComponent (“java.awt.List”, “list”); addComponent (“java.awt.Multiselector”, “selector”); addToContainer (“list”, “selector”); linkEvent (“paint”, “list.paint”); linkEvent (“select”, “selector.select”); linkEvent (“deselect”, “selector.deselect”); linkEvent (“close”, “selector.close; list.close”); }

19. ListMultiselector GUIList, MultiSelector FrameList JFrame, GUIList Instantiation MergeMasterClient ($master, $client)

20. Composition Operators Composition Templates Composition Contracts XDescriptors XCompose Basics Goals Ingredients New requirement Asset Specification New technology Flexibility Extensibility Reusability Correctness Portability Composition Patterns www.cs.uml.edu/~ntansala

21. XDescriptor <class name=“GUIList”> <properties> </properties> <events> <event name=“”paint” refer=“”/> <event name=“”close” refer=“”/> </events> <methods> </methods> <composition> </composition> </class>

22. XDescriptor <class name=“ListMultiselector”> <properties> </properties> <events> <event name=“”paint” refer=“list”/> <event name=“”select” refer=“selector”/> <event name=“”deselect” refer=“selector”/> <event name=“”close” refer=“selector;list”/> </events> <methods> </methods> <composition> <component name=“java.awt.List” id=“list”/> <add id=“selector”/> </component> <component name=“java.awt.Multiselector” id=“selector”/> </composition> </class>

23. JavaBeans CORBA COM XDescriptor Library System Architecture XCompose Engine XDescriptor XDescriptor Wrapper GUIList XDescriptor Deployment Engine GUIList

24. System Architecture (con’t)

25. Discussion ? • What is the complete set of operators and their semantics to provide flexibility and extensibility ? • What extensions are needed to make XCompose platform and component model independent ? • Is XML the right model? • What are the tradeoffs to achieve the five goals ? • Are the five goals sufficient ? Are there any other goals that need to be supported here ?

26. Questions ?