2. Agenda
Modeling platforms and Platform Independence
Model Transformations
MDA in the Eclipse IDE
The Atlas Transformation Language
3. CIM, PIM and PSM
CIM: Computation Independent Model
A vocabulary of a problem domain useful to a
variety of stakeholders
PIM: Platform Independent Model
A specification of a system that does not take into
account technical details of a specific platform
PSM: Platform Specific Model
A specification of a system expressed in terms of
the specification model of the platform
4. The MDA process (abstraction)
www.ibm.com/developerworks/ibm/library/i-modev1/!
8. MDA: Mappings between Models
From PIM to Specific
Platform- Middleware
Independent
Technologies via OMG
Model
Standard Mappings
CORBA Java/EJB XML/SOAP Other
Model Model Model Model
From PSM to
application interfaces,
code, GUI descriptors,
SQL queries, etc.
CORBA Java/EJB XML/SOAP Other
9. Model Representation
UML Model (PIM) XMI Document
Auto <Auto>
<Color> Red </Color>
Color : String MOF
<Door> 4 </Door>
Door : Integer
<Engine> 2 </Engine>
Engine : Integer
</Auto>
XMI DTD, Schema
IDL, Java… <!Element Auto
interface Auto (Color*,
{ Class Auto Door*,
}; {public String color; Engine*)>
public int Door;
public int Engine;
}
10. Model Transformation
Working with interrelated models requires to ensure
their vertical, horizontal, and evolutionary consistency
This activity can be performed taking one or more
source models as input and producing one or more
target models as output
The process of model transformation must comply with
a set of transformation rules
12. PIM to PSM Transformation
It is used when the PIM is mapped into
a platform specific infrastructure
The transformation is based on a set of
platform features
These features should be described by
UML
13. PIM to PIM Transformation
It is used when models are enhanced,
refined or filtered during the
development lifecycle without needing
any platform specific information
Example: analysis-to-design model
transformation
14. PSM to PSM Transformation
It is used for component realization
and deployment
Generally, it is related to platform
dependent model refinement
15. PSM to PIM Transformation
It is performed for abstracting models of
existing technology-dependent
implementations into a platform independent
model
It is a refactoring process hard to be fully
automated
16. Model Mapping
A technique for setting the specifications, that drives
the transformation from the source model to the target
model
The main mapping techniques are [8s]:
Model-Type mapping
The mapping is realized between platform-independent data types and platform-
specific data types. The two kinds of data type drive the transformation
Metamodel mapping
The mapping is realized between the PIM metamodel data type and the PSM
metamodel data type.
Model-Instance mapping
It uses marks, i.e. concepts of the target-model explaining how to transform source
model elements
20. Approaches to Model Transformations
The tools performing model transformations can use:
Direct transformations: internal model representation
manipulated by specific APIs
Intermediate transformations: model exported in an
external standard form (e.g., XMI) that can be manipulated
Transformation language: a language with specific
constructs for defining and applying transformations
21. Platform Independence
Platform Independence is a “fuzzy” concept
It means independence from a specific execution and
development domains
The domains from which the independence can be
asserted are the usual software engineering
abstraction domains:
Programming Languages
Software Architectures
Operative Systems
Data Representation
22. Ex.: Bank Account Architectural PIM
• Nothing said about the
architecture and the
developing technologies
• It is the model used by bank
manager and stakeholders
23. Ex.: Bank Account Architectural PSM
• It specifies a remote and some local objects
• It adds some implementation information
• It is the model used by analyst and
programmers
• it conforms to the PIM
• it can be a PIM for a further platform specific model
24. MDA Tools
Currently, there are no tools that implement MDA
as envisioned by the OMG community
MDA itself is still being defined
Existing tools allow partial transformations
They are usually limited to
specific platforms
specific languages
specific transformations
Usually they are evolutions of tools born in other
research fields
Especially in Generative programming and
Metaprogramming
25. EMF and ATL
Two interesting technologies are emerging that are
more and more used in MDA tools:
1. The Eclipse Modeling Framework (EMF) is the
analogous of MOF in the Eclipse IDE Platform
It consists of an extended set of API, a metamodelling
framework named Ecore and an Eclipse IDE plug-in
2. The Atlas Transformation Language (ATL) is a
language specifically targeted for model
transformations
It supports MOF 1.4 and Ecore while conforming to MDA
transformation specifications
26. MDA and Middleware
Middleware is an enabling
technology for MDA
Generators’
increasing
complexity
27. From Coding to Modeling
What is the difference between programming
language abstractions and MDE/MDA
abstractions?
The former allow to abstract the solution space
they are “computing oriented”
MDE/MDA allow to abstract the problem space
they are “application domain oriented”
The current Enterprise Computing scenario
requires to move the software development
emphasis from coding to modeling systems
28. Metadata Integration
Why we cannot use a single language to describe all the
aspects of a system?
The problem is not that we
use different languages to
describe different aspects of
software components
The problem is that we have
no overall architecture for
integrating specifications
made in different languages
MDA defines a single
architecture for the integrated
management of metadata
29. The Eclipse IDE in a Nutshell
Eclipse is an open Universal Tooling Platform
Open Source licensed via Common Public License
Managed via the Eclipse Project (www.eclipse.org)
Maintained by the Eclipse Foundation
An independent consortium whose members include: IBM, SuSe,
Borland, RedHat, HP, SAP, OMG
It provides an open platform for application
development tools
It runs on a wide range of operating systems
It is language-neutral
It facilitates seamless tool integration
It adds new tools to existing installed products
30. What is Eclipse?
A general purpose IDE
An open, extensible architecture based on plug-ins
Plug-in development environment PDE
Java development tools JDT
Eclipse Platform Platform
Standard Java2 Virtual Machine Java VM
31. The Eclipse Architecture
Another
Eclipse Platform
App
Java Workbench Help
Development
Tools JFace
(JDT)
SWT
Team Your
Tool/App
Plug-in Workspace
Development Debug
Environment
(PDE)
Their
Platform Runtime Tool
Eclipse Project
32. MDA in Eclipse
There are a number of plug-ins that support
the MDA features in Eclipse
Indeed, there is not a single tool that gives a
full support of MDA features as envisioned
by the OMG
Three MDA plug-in categories can be
identified basing on their focus:
1. Models representation and management
2. Models transformation
3. Models-to-Code generation
33. Notable MDA Projects in Eclipse
Name Description Categ./
License
Acceleo A MDA based code generator for various target middleware 3 / Free
and languages: Java EE, C#, Python, PHP etc.
Atlas It defines a management environment for MDE repositories 1 / Free
based on the "megamodel" approach. A megamodel is a
Megamodel registry of model resources available in a given scope (a
Management zone) In order to manage megamodels users may use
(AM3) metamodels from a library or invent their own ones for new
kinds of artifacts.
Atlas Model A tool for representing correspondence between models by 1 / Free
means of a model (named weaving model). Common
Weaver (AMW)
weaving use cases are: data exchange, data integration,
model merging, etc
Atlas A model transformation language that provides 2 / Free
ways to produce a set of target models from a
Transformation set of source models. It also provide a toolkit
Language (ATL) (the ATL IDE) with a number of tools aimed to
ease the development of ATL transformations.
34. Notable MDA Projects in Eclipse
Name Description Categ./
License
Epsilon It can be used to manage models of different modeling 1/Free
technologies using a family of integrated model
management languages. It can be used for model
navigation, modification, transformation, validation and
comparison. It also provides tools for defining and
executing wizard and for code profiling and monitoring.
IBM Model Is a set of tools that helps to make comparisons, check 2 / IBM
consistency, and implement transformations between License
Transformation Eclipse Modeling Framework (EMF) models.
Framework
Kermeta A metaprogramming environment based on an object 2 / Free
oriented executable meta-modeling paradigm: a
Domain Specific Language (DSL) optimized for
metamodel engineering. It allows model and metamodel
management, weaving and transformation.
35. Notable MDA Projects in Eclipse
Name Description Categ./
License
openArchitectur It is suite of tools and components supporting in 1, 3 / Free
model driven software development. It is built upon a
eWare modular model-to-code generator framework
implemented in Java. It supports arbitrary import (model)
formats, meta models, and output (code) formats It is “a
tool for building MDA tools”
AndroMDA AndroMDA is an extensible generator framework that 3 / Free
adheres to MDA. Models from UML tools are
transformed into deployable components different
platforms: J2EE, Spring, .NET. It provides patterns for
Axis, Struts, JSF, Spring, Hibernate and other toolkits
QiQu It transforms an UML-model into source-code (Java, C#, 3 / Free
Cobol etc.). It relies on XMI and allows to build a
domain-specific generator that transform models into
code or anything else (XML, HTML, Scripts, Excel etc.)
Modeling Eclipse Plugins: http://www.eclipseplugincentral.com/Web_Links-index-req-viewcatlink-cid-11.html
36. MDA Enabling Technologies in Eclipse
There are a set of de-facto standard Eclipse
plug-ins that enable MDE features
These plug-ins enable upper-standing MDA
plug-ins to operate
We consider an essential subset of these
plug-ins in order to start experiencing with
MDA
38. QVT (Query View Transform)
QVT is an OMG specification
QVT extends OCL 2.0 to imperative OCL
QVT defines 3 DSL named Relations,
Core and Operational Mappings
Relations and Core are declarative
languages
OperationalMapping is an imperative
language with constructs like loops,
conditions, etc.
39. A Transformation Language: ATL
The Atlas Transformation Language (ATL)
is an answer to the OMG Query View and
Transformation (QVT) RFP
ATL is a QVT-like transformation language
and engine with a large user community and
an open source library of transformations
ATL provides the developers with a mean to
specify the way to produce a number of
target models from a set of source models
40. Eclipse and Modeling Plug-ins
The Eclipse Modeling Framework (EMF) is a
framework and a code generation facility
It allows to define and mange models in Java,
XML and UML
It relies on a meta-metamodel named Ecore
UML2 is an EMF-based implementation of the
UML 2.x metamodel
It provides the support for UML model plug-ins
It defines a common XMI schema for diagram
interchange
41. Eclipse and Graphical Plug-ins
The Graphical Editing Framework (GEF) allows
to create a graphical editor under Eclipse
GEF provides a layout and rendering toolkit for
displaying graphs, manage palettes, handle and
resize graphical objects
The Graphical Modeling Framework (GMF)
provides components and runtime
infrastructures for developing graphical editors
based on EMF and GEF
reusable components for graphical editors
generative infrastructure to graphical editor production
42. UML Modeler Plug-ins
Name Description
OmondoUML It is a visual modeling tool based on UML2. It supports
reverse engineering and production code for EJB,
Struts, Web Services. It is based on GEF and EMF.
Papyrus It is an open source product to model in UML2. It
allows to graphically represent diagrams in the
Diagram Interchange (DI2) OMG standard. It supports
Java and C++ code production and some UML
profiles (e.g. SysML)
Topcased It is a software engineering toolkit that provides
various modelers such as UML, Ecore, SysML. It is
compliant with the requirements of critical and
embedded applications
Eclipse ArgoUML It integrates the ArgoUML open source tool in the
Eclipse platform. It is a complete UML modeler
integrated with the AndroMDA MDA plug-in.
43. The ATLAS Transformation Language
ATL is a model transformation language
Specified both as a metamodel and as a textual concrete syntax
It is both declarative and imperative
declarative style is the default choice for simple transformations
source model elements are navigated by means of a set of rules that
create target model elements
It relies on a ATL Virtual Machine that allows transformations
A transformation from the ATL metamodel to the VM code enables to
“execute” ATL transformations
It has been implemented as an Eclipse plug-in
44. ATL Architecture
Execution Engine
Virtual Machine
ATL to bytecode compiler
Eclipse IDE used for
Editor with syntax highlighting
ATL launch support
Source debug
45. ATL Mapping Technique
The mapping technique used by ATL is
metamodel-based
MMM: MOF or Ecore [13]
MMt: ATL metamodel
Mt: ATL transformation model
MMa: source metamodel
MMb: target metamodel
Ma: source model
Mb: target model
Conforming to OMG Q/V/T specifications the transformations (Mt) are
defined as models as well conforming to the ATL metamodel (MMt)
46. ATL Transformations
ATL allows to define different types of
transformations
ATL Modules: are model to model
transformations
ATL Queries: are model to primitive datatype
transformations
ATL Libraries: factorize the ATL code in order
to be imported and used in multiple
transformations
An ATL transformation file has the .atl
extension
47. ATL Modules
Modules enable ATL developers to specify
the way to produce a set of target models starting
from a set of source model
Modules are structured in three sections:
Header section that defines some attributes relative
to the transformation
Helpers that are similar to Java methods
Rules that define the way target models are
generated from source models
48. ATL Rules
There are two different types of rules
Matching Rules: for ATL declarative specifications
to define for which kind of source elements target elements must
be generated
to define the way the generated target elements have to be
initialized
Called Rules: for ATL imperative programming
they are a particular type of header that can generate target
model elements
It has to be called from an imperative code section
49. ATL Execution Modes
ATL defines two different execution modes for its modules:
Normal execution Mode
Explicitly specifies how each target model element must be generated
from source model elements
Refinement execution Mode
Source model elements are implicitly copied from the source to the
target model
ATL developers focus on the generation of the modified target
elements
It is limited to the transformation of a single source model to a single
target model conforming to the same metamodel
57. ATL DataTypes
The ATL language is based on the OMG Object
Constraint Language (OCL)
Primitive DataType
Boolean, Integer, Real, String
Collection DataType
Set, OrderedSet, Sequence, Bag as collection_type
(element_datatype)
Tuple DataType
TupleType(var_name1 : var_type1, ..., var_namen :
var_typen)
Map DataType
Map{(key1, value1), ..., (keyn, valuen)}
Model Element DataType
metamodel!class
58. An ATL Transformation
Author Person
+name : String +name : String
+surname : String +surname : String
The Author Source Metamodel The Person Target Metamodel
The goal is a model to model PIM to PSM transformation
name and surname attributes must be preserved
An instance of Author is mapped into an instance of
Person
59. An ATL Transformation
module Author2Person;
create OUT : Person from IN : Author;
rule Author {
from
a : Author!Author
to
p : Person!Person (
name <- a.name,
surname <- a.surname
)
}
60. Conclusion
MDE is a new step of the object technology
In the 80's objects and classes were seen as "first class entities",
with libraries of several hundred of classes hierarchically organized
Models and metamodels are considered first class entities now
Libraries (lattices) of hundreds of metamodels highly abstract are
beginning to appear. Each metamodel may contain several
hundreds of concepts and relations
Several tools can work with these libraries of models and
metamodels
Research is needed to bring together theory and practice of model
engineering (ontologists, methodologists, software engineers,
information system designers, database specialists, etc.)
61. Self-test questions
What is a model transformation?
What is the goal of model
transformations?
What is QVT?
What is ATL?
62. References
Bézivin: On the unification power of models. Software and
System Modeling, Springer, 4:2(171-188), May 2005
Frankel, Model Driven Architecture: Applying MDA to
Enterprise Computing, Wiley, 2003
Kurtev, Bezivin, Jouault, Valduriez, “Model-Based DSL
Framework” . ACM OOPSLA, 602—616. 2006.
Mellor, Scott, Uhl, Weise MDA Distilled: Principles of
Model-Driven Architecture, Addison-Wesley, 2004
Schmidt, Model-Driven Engineering. IEEE Computer, 39:2
(25-31), February 2006.
63. Specifications and URLs
[1s] Eclipse ATL Project, http://www.eclipse.org/m2m/atl
[2s] Eclipse EMF Project, http://www.eclipse.org/modeling/emf/
[3s] OMG, “Common Warehouse Meta-model (CWM)”, Version 1.0, October
2001, http://www.omg.org/cgi-bin/doc?formal/01-10-01.pdf
[4s] OMG, “XML Metadata Interchange (XMI) Specification v1.2”, January
2002, http://www.omg.org/cgi-bin/doc?formal/02-01-01.pdf
[5s] OMG, “Meta Object Facility (MOF) Specification”, Version 1.4, OMG, April
2002, http://www.omg.org/cgi-bin/doc?formal/02-04-03.pdf
[6s] OMG, “Meta Object Facility (MOF) Core Specification”, Version 2.0,
January 2006, http://www.omg.org/docs/formal/06-01-01.pdf
[7s] OMG, “Meta Object Facility 2.0 Query/View/Transformation Specification”,
November 2005, http://www.omg.org/docs/ptc/05-11-01.pdf
[8s] OMG, “MDA Guide Version 1.0.1”, June 2003,
http://www.omg.org/docs/omg/03-06-01.pdf
[9s] OMG, “Unified Modeling Language (UML), version 1.4”,
September 2001, http://www.omg.org/cgi-bin/doc?formal/01-09-67
[10s] OMG, “Unified Modeling Language: Infrastucture”, version 2.2.1,
February 2007, http://www.omg.org/docs/formal/07-02-04.pdf
[11s] Sun, “Java Metadata Interface (JMI) API 1.0 Specification”,
http://jcp.org/aboutJava/communityprocess/final/jsr040/index.html
