Domain-Specific Development

Stuart Kent, Senior Program Manager,DSL Tools, Visual Studio Team System, Microsoft

Domain-Specific Development Pattern

Model

FixedPart

Abstraction of the variable part, expressed in a Domain-Specific Language

Framework, API, Interpreter …

Hand-crafted

Generate, interpret, some of each

Integrate

Contents

Domain-Specific Development Pattern• Demo 1 – Wizard UIP example• DSD in Software Factories

• Domain-Specific Languages (DSLs)• Integration: Generation versus Interpretation from/of models• Costs & benefits of the DSD approach

• DSL Tools in Visual Studio• Demo 2 – Building and deploying a DSL

• Release schedule• Difference between Feb CTP and V1• Follow-up session

Demo 1 – Wizard User Interaction Process

Model

FixedPart

Integrate

Expressed in Graphical Page Flow DSL

UIP frameworkWindows Forms

Additional control logic code added

Generate:• Some control logic code• Starter UI• Config file that’s interpreted

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ArchitectureFramework,Components

Process and roles

Tools

PatternsDSD Is Part of Software Factories

Libraries

Domain-Specific languages

Test suites

Models

Method & procedures

TemplatizingTemplatizing …… …… ……

TemplatizingTemplatizing …… …… ……

Guidelines

Reminder – DSD Pattern

Model

FixedPart

Abstraction of the variable part, expressed in a Domain-Specific Language

Framework, API, Interpreter …

Hand-crafted

Generate, interpret, some of each

Integrate

Domain-Specific Language Classification

Horizontal GUI web business logic database deployment

Vertical telephone bills insurance ticketing hardware construction

Domain-Specific Language

generalpurpose

specific

next slide …

Parts of a DSL

Domain Model+ validation

Reminder – DSD Pattern

Model

FixedPart

Abstraction of the variable part, expressed in a Domain-Specific Language

Framework, API, Interpreter …

Hand-crafted

Generate, interpret, some of each

Integrate

What does ‘Integrate’ Mean?

• Generate• Generate code that talks to framework APIs

• E.g. completely new classes

• Generate code that completes a framework• E.g. C# partial classes

• Interpret• The model file itself or some data pushed into a live

environment from the model (e.g. xml configuration file, data in a database) is interpreted

• A Combination of the above

• Easier to produce initially• More customisation options

• Behaviour can be changed at run-time• Fewer artifacts to keep in sync

Customisation (1)

What?

• Customise/extend the behaviour expressed by the model + fixed part

Why?

• However good the fixed part, not every point of variability will have been predicted

• Some things (e.g. complex logic) are just easier to express in code – avoids reinventing programming languages in a DSL

• There will be undiscovered bugs in the code generators / interpreter / framework which need to be fixed somehow

DSL Area

customisation

Customisation (2)

DSL Area

Customisationstep

Expertcustomisation

step

Platformcustomisation

Hand crafted code for specific plug-points

Change the code generators

Change the framework

customisation

Customisation (2)

DSL Area

Customisationstep

Expertcustomisation

step

Platformcustomisation

Hand crafted code for specific plug-points

Change the code generators

Change the framework

Interpretation

Generation

Domain-Specific Development – Cost / Benefit

Benefits• Fewer copies of the same code to

maintain

• Fix bug in code generators or framework fixes for all

• Change in requirements (e.g. business rules) = change in model

• Change in technology = change in code generators / framework

• Better communication with stakeholders

Cost• Creating/maintaining the DSL / code

generators / framework potentially across many projects and versions

Model

FixedPart

Integrate

Goal of Microsoft DSL Tools is to bring down this cost

DSL Tools in Visual Studio

What?

• Tools for authoring and deploying DSLs and template-based text artefact (e.g. code) generators

Where?

• Now installed as part of the Visual Studio SDKhttp://msdn.microsoft.com/vstudio/extend/

• Also seehttp://msdn.microsoft.com/vstudio/DSLTools/

Reminder – Parts of a DSL

Domain Model+ validation

DSL Tools V1

Designer for a DSL in Visual Studio

Domain Model Framework

DesignSurface

Framework ShellFramework

TemplatingEngine

ValidationF’work

DSL Tools – Modeling Platform

In-memory graph In-memory graph database with rich database with rich

services (e.g., services (e.g., transactions, transactions,

serialisation, rules …) serialisation, rules …) Extensible Extensible drawing surface drawing surface with support for with support for

routing and routing and auto-layout auto-layout

Artefact Artefact generatigenerati

on on

Checks constraints Checks constraints and guides user to and guides user to

resolve issuesresolve issues

Visual Studio Visual Studio UI integration UI integration

for for components components like toolbox, like toolbox,

menus, menus, properties properties

grid, explorergrid, explorer

DSL Tools – Architecture of a Designer

Domain Model Framework

DesignSurface

Framework

generateddomain classes

generatedshapes

ShellFramework

generatedserialisers

TemplatingEngine

generateddirectiveprocessor

generatedshell code

generatedshape 2 class mappingstext

templates

DSL Definition

generate

hand-crafteddesigner extensions

ValidationF’work

hand-coded

validationlogic

A DSL for Activities

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Defining a DSL, Step 1: Define Domain Model

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Defining a DSL, Step 2: Define Notation

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Defining a DSL, Step 3

Define visualisation of domain model via notation elements

ShapeShape Domain ModelDomain Model

Demo 2 – Building & Deploying a DSL

Customize & Extend Designer

CreateAuthoringSolution

Customize DSL

GenerateInstaller

AddCode

GenerateCode

F5

Exercise tools

Create project

templates

Deploy !

Work withdesigner

Createtext

templates

Contents

Domain-Specific Development Pattern Demo 1 – Wizard UIP example DSD in Software Factories

Domain-Specific Languages (DSLs) Integration: Generation versus Interpretation from/of models Costs & benefits of the DSD approach

DSL Tools in Visual Studio Demo 2 – Building and deploying a DSL

• Release schedule• Difference between Feb CTP and V1• Follow-up session

Release Schedule

• February 2006, part of VS SDK

• May 2006, V1 Release Candidate(as part of VS SDK CTP released in that month)

• August 2006, V1 RTM(as part of VS SDK V3 released in that month)

Differences between Feb CTP and V1

• Cleaner APIs

• A single DSL definition format• combines domain model and notation aspects

• more flexible mapping between notation and domain model

• A DSL Designer (edits the DSL definition format)

• Serialisation• Domain-Specific serialisation format in XML

• forgiving, version aware reader

• Extra notation – ports & swimlanes

• Customisation• more explicit customisation points called out

• generated code is easier to override

Replace <object type=“MyX”> … </object>with <MyX> … </MyX>

Follow-up Session

Domain-Specific Languages Futures

• Led by Gareth Jones, Developer, DSL Tools

• At 12.00, after break, in Denbigh 1 (Workshop 2)

• Come and discuss the features you’d like to see in future versions of DSL Tools

• Please bring signed Design Preview Agreement form(blank forms are available if you haven’t got one)