roles in software development using domain specific modelling languages

Roles in Software Development using Domain Specific Modelling Languages

Holger Krahn, Bernhard Rumpe, Steven VölkelSoftware Systems EngineeringTechnische Universität Braunschweig

http://www.sse.cs.tu-bs.de/

cvs://mc/doc/praesentationen

Holger KrahnSoftware Systems EngineeringTU BraunschweigSeite 2

Roles in Software Development usingDomain Specific Modelling Languages

An agile development process involving DSMLs1.

HMI example2.

MontiCore3.

Conclusion4.



Problem setting:Using off-the-shelf generators

Off-the-shelf generators• DSMLs cannot be changed on demand

→ Notations are not domain-specific as possible• Generator using templates can be changed

→ But: General structure of generation isnot changeable

Modification of generated codeis often needed

→ Round-Trip is often not possible

Desired modification of codecannot be expressed in DSML

DSML instance

developergenerated code

Handwrittencode

productdeveloper



Tool development inside the project:Roles in Process using DSMLs

Language developer• defines or enhances an existing

DSML Tool developer

• writes code generators for DSML• comprises tools

Product developer• uses tools developed in

the project to influenceoutcome

Library developer• develops software libraries • Thereby simplifies the code

generator

DSML

codegenerator

languagedeveloper

productdeveloper

DSML instance

librarydeveloper

generated code

SW-Library

tooldeveloper



Principle:The generated code is never changed

Generated code• is never changed manually • not part of the source code shared between developers

(Only DSMLs and hand-written code are shared)

Pros• round-trip engineering is not needed• no inconsistencies between generated code and DSML• build process is clear to understand and can be automated• DSMLs and hand-written source code are the primary artifacts

that determine the behavior of the resulting system

Cons/Additional requirements this approach • Generated code needs interfaces to interact with manual code• DSMLs need gaps where exceptions of the standard generation

can be specified



Human-Machine-Interfaces

Human-Machine-Interfaces (HMIs) in cars• provide user interface• have different functionality depending on the configuration

of the car Main reasons for using DSMLs and code generation

• Separate menu structure (which might change rapidly during development) from look&feel (that is fixed for a manufacturer)

• Ensure by design that the HMI software can handlemultiple configurationscorrectly

status bar

central panelbuttons



Roles in the HMI example

generates

input

input

uses

DSLTool framework (Part of MontiCore)

HMISoftware

FeatureDSL processor

MenuDSL processor

Manually defined

generator

Manually written HMI-Library

FeatureDiagram

MenuStructureDiagram

DSMLMenu Diagrams

DSML Feature

Diagrams

MontiCorecodegenerator

MontiCorecodegenerator

defineslanguagedeveloper

productdeveloper

defines

librarydeveloper

tooldeveloper

designs

designsprograms

assembles

programs



Agile Values & Methods

Communication• DSMLs allow to communicate in domain specific notations

Simplicity• As generated code is strictly not modified:

models and handwritten code are used at same level of abstraction (they are the primary development artifacts)

• Language-based approach:For domain experts possibly easier to understand than (meta)metamodels

Feedback• On-site customer:

Might be a product developer(who directly influences the resulting software)



Agile Values & Methods

Courage• Courage is needed to change DSML or generator

Humility• Different stakeholders have different expertise:

Directly reflected in the different roles

Continuous Integration• text-based approach allows to use standard versioning systems• no release plan for internal tool in project is needed, because it

can be automatically build on demand Refactoring

• Refactoring should work on interacting source code and models Testing

• models can be used for production code and testing



Features of MontiCore supportingan agile development process

Generation of reusable language components for different tools and use inside other languages

Generation of Java source code that can be easily integrated in other applications

Standardized solution for implementing a generator• model traversal• file and error handling• processing of DSML separated in transform and workflow layer• template engine partially supporting generator refactoring

Reusable ant scripts to compile a project whenever an artifact is changed• DSML definition• DSML instance• code generator• hand-written source code



Conclusion

Transfered agile values & methods for code-based development to a process where DSML are used

Explained the different roles developers play in such an process Agility is improved by

• Making the on-site customer a first class developer• DSMLs support the communication

Principle of not modifying generated code ensures that models and code are used at the same level of abstraction

MontiCore simplifies the development of tools inside an agile project

Open issues• How do Refactorings look like that are applied to interacting

DSMLs and source code?• Which predefined DSMLs are frequently required?

roles in software development using domain specific modelling languages

Documents

hmi software

handwritten code

software libraries

handwritten source code

code needs interfaces

generated codeis

tool development

interfaces hmis