Eclipse Modeling Project Advantages and Disadvantages

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w w w .ict.tu w ien.ac.at

IT

Vertiefung

Edin Arnautovic Institute of Computer Technology /99 Edin Arnautovic Wolfgang Radinger w w w .ict.tu w ien.ac.at

Model

‐

Driven

Software

Development

MDSD Concepts

Metamodeling, MOF, Ecore

MDSD Process

Model Driven Generation

OMG Model Driven Architecture

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MDSD Concepts

Warum

modellieren

wir?

Modelle sind notwendig

• um Informationen verständlicher darzustellen

• um essentielle Systemaspekte aufzuzeigen

• zur Kommunikation (Projektmitglieder, Kunde)

• um komplexe Systeme darstellen zu können

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(2)

Models

in

Traditional

Engineering

As old as engineering

Traditional means of reducing engineering risk

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Computer Technology /99

from Brian Seltic

What

Engineers

Do

Before they build the real thing...

…they first build models…and then learn from them

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from Brian Seltic

Models

Engineering model

• A reduced representation of some system that is easier to understand than the actual system

How Models are Used

• To detect errors and omissions and to determine key tradeoffs

in complex designs before committing full resources to

realization

−Through (formal) analysis and experimentation −Investigate and compare alternative solutions

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g p

−Minimize engineering risk

To communicate with stakeholders

• Clients, users, implementers, testers, documenters, etc.

To

drive

implementation

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Models

are

the

new

code

High Level

When the system evolves or a problem occurs, modify a model, or a mapping, not the code!

Assembly Code M hi C d Assembler Executable Models S C d Model Compiler Assembly Code Source Code Compiler High Level Language Source Code Institute of Computer Technology /99 Machine Code 1960’s None Source Code 2000’s Software Platform Assembly Code 1980’s Hardware Platform

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What

is

MDSD?

MDSD = Model‐DrivenSoftware Development

• different than model‐based

Models are first‐class objects

Based around domain‐driven metamodeling

It is also: development of infrastructureto develop software

(software factories) Institute of Computer Technology /99 (software factories) w w w .ict.tu w ien.ac.at

Model

based

vs.

model

driven

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Reasons

for

using

MDSD

• You want to provide a way for your domain‐experts to formally specify their

knowledge, and to provide a way for your technology people to define how this is implemented

(using model transformations).

• You might want to provide different implementations (i.e. more concrete models)

for the same model, perhaps because you want to run it on different platforms (.NET, Java, CORBA).

• You may want to capture knowledge about the domain, the technology, and their mapping in a clear, unclutteredformat.

• In general, you don’t want to bother with implementation details when specifying your functionality.

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• MDSD results in a fan‐out, i.e. one set of models can be the source for transformations to several targets.

• Another reason for using MDSD: You are working in the context of product lines

and software system familiesand need to develop domain‐specific assets.

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Advantages

of

MDSD

Better integration of domain experts

Faster software changes

Validation of software‐under‐construction

Better realization of the software architecture

Enhanced portability to other platforms

More efficient for product line development

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Disadvantages

of

MDSD

Higher overhead for one‐of‐a‐kind system

Concepts

Modelsexpressing the application functionality based on

domain specific languages

Domain specific languages, usually expressed by metamodels Platformscontains common middleware (e.g. CORBA, J2EE, or

.NET) and domain specific frameworks

Transformationsto map models to platforms

How

MDSD

works

Developer develops model(s) based on certain metamodel(s), expressed using a DSL. Model Model Model Metamodel

Using code generation templates, the model is transformed to executable code.

• Alternative: Interpretation

Optionally, the generated code is

mergedwith manually written code.

Transformer Tranformation Rules Model Metamodel opt ional, can b e r e peated Institute of Computer Technology /99 g y

One or more model‐to‐model

transformation stepsmay precede

code generation. - 15 -Transformer Code Generation Templates Generated Code Manually Written Code optional © 2 0 0 4 M a rk u s V ö l t e r w w w .ict.tu w ien.ac.at

Domain

Driven

Development

Domain Driven Development is about making software

development more domain‐related as opposed to

computing related. It is also about making software

development in a certain domain more efficient.

Domain Concepts Domain Concepts

mental work of developers Institute of Computer Technology - 16-/99 Software Technology Concepts Software Technology Concepts © 2 0 0 4 M a rk u s V ö l t e r

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What

is

a

„Domain“

A definitioncould be:

A domain is a bounded area of knowledge or interest.

Examples (from the world of Software) include:

• eBanking • Embedded Software • Web‐Based eBusiness Applications Institute of Computer Technology /99 pp • Control Software for 4‐Cylinder Diesel Engines • Astronomical Image Processing Software

Domains can have varios „scopes“ as well as various

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„Kinds“

of

Domains

In the context of software development it is also useful to distinguish (at least) two kinds of domains:

• Functional Domainsrepresentp the business/professional/p issues;; −Banking −Human resource management −Insurance −Engine Controllers −Astronomical Telescope Control Institute of Computer Technology /99

• Technical Domains adress key technical issues for software development

−Distribution, Failover and Load‐Balancin −Persistence and Transactions −GUI Design −Concurreny and Realtime - 18 -© 2 0 0 4 M a rk u s V ö l t e r w w w .ict.tu w ien.ac.at

Domain

Specific

Language

Defines the semantic of the model

The notation (concrete syntax)of the DSL can be textual or

graphical

More important: The DSL’s abstract syntax, better known as

metamodel

Metamodeldefines the model elementsfor domain modeling

The DSL’s semanticsare used to transformthe DSL to general‐

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Metamodeling /

Meta Object Facility

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Klasse

vs.

Objekte

Klassen stellen Konzepte dar. Bei OOP werden sie in einer OO‐

Programmiersprache implementiert

• Objekte dieser Klasse existieren zur Ausführungszeit, um das Verhalten

und Wissen des Systems bereitzustellen.

Klasse Objekt Auto Kennzeichen :Auto W 12345 A :Auto W 1111 AB Institute of Computer Technology /99 :Auto W 2222 XY :Auto S 1234 XY w w w .ict.tu w ien.ac.at

Objektdiagramme

Statische Objektdiagramme sind manchmal hilfreich

• Bei der Erläuterung des Klassendiagramms

• Bei Schwierigkeiten mit der Klassifikation

• Zur Untersuchung der Multiplizität

• Zur Darstellung von Vorher‐und Nachher‐Zuständen

myFlug:Flug Abflugort = VIE Zielort =LAX Institute of Computer Technology /99 leg_1:Leg Abflugort = VIE Zielort =FRA leg_2:Leg Abflugort = FRA Zielort =LAX w w w .ict.tu w ien.ac.at

Aggregation

Die Aggregation bestimmt Ganzes Teil Beziehungen.

Besitzverhältnis

• Die Klasse die das Ganze darstellt besitzt die Klasse die die Teile

modelliert, und steuert den Zugriff.

Lebensspanne

• Das Ganze erstellt und löscht die Teile.

Zugriffsmöglichkeiten

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Zugriffsmöglichkeiten

• Auf die Teile wird über das Ganze zugegriffen.

Weiterreichung

• Einige Operationen auf der Ebene des Ganzen bewirken die

gleichen Operationen bei den Teilen.

Beispiel:

Aggregation

M hl it {or} Mahlzeit

Suppe Salat Hauptgericht Dessert

1 1 1 1

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Multiplizitäten

Bereiche • [min – max] z.B. [1..10] • * Æbeliebig z.B. [0..*] genau 1: 1 ≥0: * oder 0..* 0 ∨1: 0..1 fixe Anzahl (z B 3): 3 Institute of Computer Technology /99 fixe Anzahl (z.B. 3): 3 Bereich (z.B. ≥3): 3..* Bereich (z.B. 3-6): 3..6 Aufzählung : 3,6,7,8,9 oder 3, 6..9

Folie Hitz & Kappel, UML @ Work

Komposition

Die Komposition ist eine starke Aggregation.

Drückt eine physikalische Inklusion der Teile im Ganzen aus.

Teile und Ganzen bilden eine Einheit

Kaffeetisch 1 Institute of Computer Technology /99 Tischplatte Tischbein 1 4 1 w w w .ict.tu w ien.ac.at

Metamodel

Meta‐: means about

Metamodel: describes the possible structure of models

conforming to the metamodel

Real-world

elements model elements metamodel elements

Domain Model Metamodel

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Metamodeling

1

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Metamodeling

2

Metamodeling allows for the modeling of modeling languages

• Analogy to EBNF for programming languages. E.g. C: −<function-definition>::= <function-heading> <function-body> −<function-heading>::=

<return-type> <function-name>'('<formal-parameter-phrase> −if ( <expression> ) <statement 1> else <statement 2>

Metamodeling allows thedefinition of tailored ordomain‐

specific modeling languages

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p g g g

A metamodel definesthe abstract syntaxof a modeling

language

Model : Metamodel = Instance : Class

Use

case

– model

Use

case

– metamodel

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Computer Technology _{Nico Suchold} openArchitectureWare/99

Example

1:

Model

and

Metamodel

interface Sensor { operation start():void; operation stop():void; operation measure():float; operation measure():float; } interface Controller { operation reportProblem(Sensor s, String errorDesc ):void; } {ordered} Interface Operation Parameter Institute of Computer Technology - 32-/99 * name : String type : String name : String type : String type : String Exception * * © 2 0 0 4 M a rk u s V ö l t e r

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Example:

Architecture

‐

centric

Metamodel

Domain

‐

centric

Model

Domain

‐

centric

Metamodel

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Meta‐Object Facility

(

MOF

)

Object Management Group

Institute of

Object Management Group

MOF

– Meta

Object

Facility

Is an object‐oriented modeling language Uses UML syntax

Used to formally define UML by the OMG

UML 2.0 was also an aiming a redefining the UML formally

based on an extended MOF

MOF

Object

Management

Group

(OMG

)

OMG’s

Mission

Since

1989

Æ

Develop

an

architecture,

using

object technology,

f

di t ib t d

li ti

i t

ti

t i

for

distributed

application

integration,

guaranteeing:

• reusability of components

• interoperability & portability

• basis in commercially available software

Specifications

freely

available

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Implementations

exist

Member

‐

controlled

not

‐

for

‐

profit

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OMG’s

Major

Successes

Common

Object

Request

Broker

Architecture

• CORBA® remains the only language‐and platform‐neutral interoperability

standard

Unified Modeling Language

• UMLTM_remains_the_world’s_only_standardized_modeling_language

Common Warehouse Metamodel

• CWMTM_,_the_integration_of_the_last_two_data_warehousing_initiatives

Meta‐Object Facility

Institute of

Meta Object Facility • MOFTM_,_the_repository_standard

XML Metadata Interchange

• XMITM_,_the_XML_‐_UML_standard

© Richard Mark Soley

OMG’s

Metalevels

describes instance of MOF

(Meta-Object ili ) M1: Model M2: Metamodel M3: Meta-metamodel instance of describes instance of describes Facility) Institute of Computer Technology /99 M0: Instances M1: Model instance of describes w w w .ict.tu w ien.ac.at

MOF

Example

The

relationship

between

metamodel and

model

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Class

Diagram

Ù

Object

Diagram

Level n Institute of Computer Technology /99 Level n + 1 w w w .ict.tu w ien.ac.at

ECLIPSE MODELING FRAMEWORK

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ECLIPSE MODELING FRAMEWORK

Eclipse

Modeling

in

a

Nutshell

Eclipse Modeling is the umbrella project for all things modeling that happen on the Eclipse platform:

The Eclipse Modeling Project focuses on the evolution and promotion

of model‐based development technologies within the Eclipse community

by providing a unified set of modeling frameworks, tooling, and standards

implementations.

Eclipse Modeling is not formally related to OMG, but implements

several of their standards

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several of their standards.

It is fair to say that many leading edge modeling tools are

hosted/developed at Eclipse Modeling.

Everything Open Source under the Eclipse Public License

EMP

Core:

EMF

The Eclipse Modeling Framework (EMF) serves as the

foundation: It provides the Ecore Metametamodel and

frameworks and tools around it for tasks such as

• Editing • Transactions • Validation • Query i ib i / i ( j ) Institute of Computer Technology /99

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EMF (2)

Modeling framework and code generation facility for building

tools and other applications

• Model specification described in XMI

• Models can be specified using annotated Java, XML documents and

modeling tools

• Foundation for interoperability with other EMF‐based tools and

applications

Provides tools and runtime support for models

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pp

• Set of Java classes for the model

• Set of adapter classes for viewing editing of the model

• Basic editor 49 w w w .ict.tu w ien.ac.at

EMF (3)

Meta model (Ecore) for describing models

Reflective API

EObject extends Notifier Æmonitor all changes to the object's

data Institute of Computer Technology 50/99 w w w .ict.tu w ien.ac.at Institute of Computer Technology 51/99 w w w .ict.tu w ien.ac.at

Domain

Specific

Language

Defines the semantic of the model

The notation (concrete syntax)of the DSL can be textual of

graphical

More important: The DSL’s abstract syntax, better known as

metamodel

Metamodeldefines the model elementsfor domain modeling

The DSL’s semanticsare used to transformthe DSL to general‐

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Definition

of

Our

Own

DSL

Two approaches for defining a DSL:

• Alternative 1: Start from scratchbased on a predefined meta‐metamodel

(e.g. MOF)

• Alternative 2:Use an available metamodel(e.g. UML metamodel) and

extend it Institute of Computer Technology /99 w w w .ict.tu w ien.ac.at

Alternative

1

Example: Metamodel for “Feature Modeling” based on MOF

Alternative

1 – Instance

of

the

Metamodel

UML Notation:

Feature Model Notation:

Alternative

2

Extending for

example the UML

metamodel: metamodel:

It can be used in the following ways:

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(15)

Alternative

2 – UML

Profiles

formally use the meta‐metamodel to extend the UML

metamodel

Since there aren’t many MOF‐based tools, UML profiles can be

used

Metamodel elementsmap to <<stereotypes>>

Metamodel attributesmap to {tagged values}

Metamodel constraintsmap to modeling constraints/rules

Example

UML

2.x

Profile

Metamodel

Enterprise

JavaBeans

Component Architecture for Enterprise Applications

Beans:

• Entity

• Session (Stateless/Stateful)

• Message

Remote and Home Access through Interfaces

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Example

EJB

Profile

Kinds

of

Metamodels

Architecture‐centric MDSD

• Represents the concept of the technical platform

• Simpler transformations

• Domain concepts can be added iteratively

• Used if no sophisticated domain‐specific metamodel available

Domain‐centric MDSD

• Useful for product line development in single domain

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Example:

Architecture

‐

centric

Metamodel

Domain

‐

centric

Metamodel

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Multiple

Technical

Domains

One DSL is usually not suitable to describe all aspects of a

complex system (e.g. persistence, GUI,…)

Define multiple domains with their metamodel

Connect them by small number of gateway meta classes

Domain

‐

centric

Metamodel

(2)

How

do

I

come

up

with

a

good

metamodel?

Incrementally!

Based onBased on experienceexperiencefrom previous projects and by mining“from previous projects, and by „mining domain experts.

A very good idea is to start with a (typically) very well known domain: the target software architecture (platform)

ÆArchitecture‐Centric DSLs Æsee below Cascading

Institute of

Æsee below, Cascading

How

do

I

come

up

with

a

good

metamodel?

II

In order to continuously improve and validatethe metamodel

for a domain, it has to be exercisedwith domain experts as

well as by the development team.

In order to achieve this, it is a good idea to use it during

discussions with stakeholders by formulating sentencesusing

the concepts in the meta model.

As soon as you find that you cannot express something using

sentencesbased on the meta model

Institute of

sentencesbased on the meta model,

• you have to reformulate the sentence

• the sentence’s statement is just wrong

• you have to update the meta model.

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How

do

I

come

up

with

a

good

metamodel?

III

Component Port owns * Interface implements 1

•

Example:

• A component owns any number of ports. • Each port implements exactly oneinterface

Component

Required Port Provided Port

provides operations defined by

provides access to operations defined by

Institute of

Each port implements exactly one interface.

• There are two kinds of ports: required ports and provided ports.

• A provided port provides the operations defined by its interface. • A required port provides access to operations defined by its interface.

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MDSD Process

Use

Cases

for

Model

Transformations

Usually, model transformations are performed as a

concretization step. Rules (using terms from the underlying

metamodel) specify transformations

metamodel) specify transformations.

• Transforming a functional analysis model to a design model for a specific

platform

• Specializing general model to a more domain specific model.

• Creating different views of a model (varying level of detail, varying focus)

• Extracting subsets or aspects of a model (mainly for analysis and

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Extracting subsets or aspects of a model (mainly for analysis and

constraint checking)

• Weaving different models together (e.g. aspects)

Modular

Transformations

Replace for other domains

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Transformer

Do not base them on concrete syntax (usually error‐prone)

Use three‐pass approach:

1. Parse source model into AST 2. Transform source AST into target AST 3. Generate concrete syntax based target model

Example:

Component

‐

Based

Integration

Architectural

Aspect

of

MDSD

Model transformations map elements of the source model to

elements of the target model

Æa restricted set of well‐defined concepts is necessary

Æthat’s a characteristic of a well‐defined architecture

ÆMDSD requires a well‐defined architecture and forces a

conform software development

Institute of

Eclipse Modeling Project Advantages and Disadvantages

IT

Vertiefung

Model

‐

Driven

Software

Development

MDSD Concepts

Warum

modellieren

wir?

Models

in

Traditional

Engineering

What

Engineers

Do

Models









To

drive

implementation

Models

are

the

new

code

What

is

MDSD?

Model

based

vs.

model

driven

Reasons

for

using

MDSD

Advantages

of

MDSD

Disadvantages

of

MDSD

Concepts

How

MDSD

works

Domain

Driven

Development



What

is

a

„Domain“







„Kinds“

of

Domains

Domain

Specific

Language

Metamodeling /

Meta Object Facility

Klasse

vs.

Objekte

Objektdiagramme

Aggregation

Beispiel:

Aggregation