Hyper/J and Concern Manipulation Environment

1. Hyper/J and Concern Manipulation Environment

2. The need for AOSD tools and development environment • AOSD requires a variety of tools • Life cycle – support all stages of artifact development • Task directed – constraint enforcement, performance, feature addition etc. • Paradigm specific – concern composition, aspect attachment

3. Problems • Lack of framework for initial tool development • Integration is difficult – most tools are implemented from scratch • Customization is nearly impossible

4. Possiblesolution • Abstraction of basic concepts of concern oriented modeling • Reusable components for tool developers • Layered architecture

5. ConcernManipulationEnvironment • Developed by IBM research labs • Presented at AOSD 2004 • Supports next generation of HyperJ • Extensible, reusable, open, customizable base for tool developers • Some ready for use tools and integration with Eclipse • Open source

6. CMEArchitecture • 4 main layers – tools, components, framework and engines • Communication between layers are through API and interfaces defined by CME • Partial implementation of the most important modules of each layer is provided by CME • Each layer is open for extension by tool developers

8. ToolsLayer • End user tools + GUI • Customized for tasks, lifecycle stages, artifacts, AOSD paradigms, environments • Intended for extension by tool developers more than other layers

9. Toolslayer–existingitems • Concern explorer for Eclipse – creation and manipulation of concern models and composition for Java • Package explorer style view • Visualize code affected by concern • Query interface • Concern modeler – express the concerns and their relations visually • For example all methods that relate to a certain feature can be grouped together to form a concern • Define concern in terms of other concern, overlap concerns, constraints on units relationship • Hyper/J2 - compositor tool for Hyper/J style concern definition and composition • Create hyperslices and hypermodules, then integrate them into existing artifact • HyperProbe – insert problem detection probes into existing software • Debugging tool implemented using aspects

10. Using CME– installation in Eclipse 3.0+ • Click 'Help' -> 'Software Updates' -> 'Find and Install'. Select 'Search for new features to install' and click 'Next'. Click 'Add Update Site'. Enter a name for the new update site you are creating, such as "CME Update Site", and enter the URL "http://download.eclipse.org/technology/cme/update". Click 'OK'. • Fully expand the CME Update Site node that appears, and select 'CME'. Click 'Next'. Select 'The Concern Manipulation Environment x.x.x' (where "x.x.x" is the CME version number shown). • Accept the license agreement

11. Using CME – UserInterface • The CME perspective is designed to be used for software exploration in which use of an editor (such as a code editor) is important

12. Using CME – Working with a project • To add the CME nature to a project, right click on that project in the Package Explorer and select 'Add CME Nature'. • CME will create a new concern model for the project • The Concern Explorer view allows you to examine the current concern model. It deliberately resembles Eclipse's Package Explorer, so navigating it should be intuitive for Java developers. For example:

13. UsingCME–Queries • To perform a query, the CME Search View is used. You can enter a query manually in the available text box, or you can use the CME Search dialog, which assists with the creation of basic queries • To use the CME Search dialog • Click the button in the CME Search view's toolbar • The dialog has three tabs, which split the queries you can create into three categories - Concern Model oriented, Artifact oriented and AspectJ-style • E.g. Searching for method calls with the AspectJ tab

15. UsingCME–Queries(cont.) • A preview of the query will be created • Queries can be saved/loaded from the dialog box • Click evaluate to perform the search • Result dialog will appear

16. UsingCME–Visualizer • The Visualiser tool provides many functions and shows an overview of where search results occur in source files

17. UsingCME–Addingafeaturetoexistingsoftware • Choose the package(s) you want to modify • Develop the feature in a separate package, using the same classes and adding new ones if required. This is equivalent to creating a new hyperslice for the feature and implementing it • Create a new concern for the feature and integrate using the composer

18. Using CME – adding a feature (cont.) • Sample code from original package:

19. UsingCME–addingafeature(cont.) • Feature code written in a separate package:

20. UsingCME – adding a feature (cont.) • Highlight the packages in the concern explorer • Right click and select "Compose New Concern“ • This brings up the Compose Concern Wizard which has been filled in to compose the two concerns you selected and to handle conflicts by merging

21. UsingCME – adding a feature (cont.) • Select name for the new concern, its location and click next • On the next screen click finish • A new package will appear in the concern explorer with both old and new functionality inside

22. UsingCME – adding a feature (cont.) • Code after merge – a new class placed in a new package in the concern explorer

23. AspectJ in CME vs. standalone plug-in • AspectJ composer in CME • No need to write aspect code directly – code can be assembled from model • Pointcut definition through query engine • Uses own view perspective • Visualizer • AspectJ plug-in • Everything must be written explicitly • Pointcut definition is done through AspectJ code • Standard Eclipse package explorer view • Visualizer

24. ComponentsLayer • Reusable components for tool builders • Separate paradigms and concrete tools aimed at specific tasks from concern representation • Separate concern representation from language constructs • API for tool developers

25. Components–existingitems • Concern Composition Component (CCC) – supports different composition semantics and weaving techniques • Defines interface for tools to specify what should be done where. AspectJ tool can use the API to define pointcuts • Control flow relations – before/after • Concern Space Management Component (Conman) – Modeling tool which represents concerns and their relationships in paradigm independent way • For example we want to state that certain concern is dependent on another as a prerequisite, and we want both the AspectJ tool and the HyperJ tool know about it

26. FrameworksLayer • Low level concern representation model • Language independent – dealing with abstract object oriented language • Pluggable for use with language specific drivers (engines) • Defines how an artifact will be manipulated to adapt to a concern

27. Frameworks–existingitems • Concern Assembler Toolkit (CAT) – provides support for assembling artifacts. XML based concern assembly language • Specify methods to be created • Specify how methods should be combine to achieve the desired result • Concern Informant Toolkit (CIT) – common interface providing information about OO elements • Inheritance relations • Accesibility of certain types within others • Method properties • Pattern Matcher (PUMA) – extensible query language processor for artifact elements • Search for classes, methods, relationships, concerns • Regular expressions

28. EnginesLayer • Language dependent • Designed to serve specific framework components • Access to source code, binary or UML/XMI • Most existing engines aim at Java related technology

29. Engines–existingitems • Java binary manipulator • Java source manipulator • XMI file manipulator • XML Serializer • Multiple engine attachment interface

30. Conclusion • Pros • Non intrusive • Can be used with existing artifacts • Extensible by tool developers • Open source

31. Conclusion • Cons • AOSD is still a new concept • Many components are not yet implemented • Limited deployment in real world projects • Heavy emphasis on specific technology, even though claimed to support wide variety