Easy and Powerful Composition of XML-based Active Documents Uwe Assmann PELAB/RISE Linköping...

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Easy and Powerful Composition of

XML-based Active Documents

Uwe Assmann

PELAB/RISE

Linköping University, Sweden

EASYCOMP Consortium

Overview

■ Introduction■ XML and Active Documents

■ Future Applications of Active Documents■ Web Objects, Active Paper and Wearables■ Traders, Agents

■ What does Software Engineering look like today?■ Uniform Invasive Composition■ EASYCOMP

Entering the Age of Active Documents

■ XML is the ASCII of the 21st century■ It will represent software and data uniformly ■ Tags will have active semantics <if> <then> <else>

■ XML documents will be active (active documents, active components)

■ Active XML-based documents will penetrate ■ the future Web, ■ future documents, and ■ future software

■ Vision stems from [Orfali/Harkey: Instant CORBA]

■ Documents■ Hypertext ■ Multimedia, e.g., Courses for Online Learning■ Web sites, server objects■ Simulated objects

■ Traders■ Wearables/Active Paper■ Agents

Everything Will Be An Active Document

Future Applications of Active Documents

Overview of Active Documents

Stationary(Web sites,Documents)

Shippable(Active paper,

Wearables)

Reflective(Agents)

Introspective(Traders)

MobileReflective

Agents

Stationary Active Documents(Web Objects, Simulated Objects)

■ Why is a web site different from a web page?■ Only a bit more complex

■ Why is a desktop different from a web site?■ Representation

■ What the difference of a web site and ■ a CAD model■ a roller bearing■ a simulated robot?

■ What's the difference between a browser and an active web site?■ Client vs server

Shippable Active Documents (Wearables, Active Paper)

■ A shippable active document can be shipped easily to other phyisical places ■ web page, web site, desktop, browser

■ Problem: Shippable Active Documents can be copied and must be integrated again

■ Examples■ Wearable computers require shippable active

documents■ Active paper require shippable active documents

Active Paper Relies on Composition Technology

■ Mr. Spielberg has married in May, Ms Anita Söderberg, from Linköping, Sweden■ he tries to reuse his E-paper tax form from last year■ His wife Anita has an E-paper tax form from Sweden■ How to both combine their papers?

■ Wearables Rely on Composition Technology■ Prof. Söderberg, Linköping works two months in Karlsruhe■ He carries his active desktop as wrist watch■ In Karlsruhe, many sub-documents change ■ When he comes home, he integrates wrist watch

Active Documents Introspecting Others (Traders)

Trader

ClientService

Mediator Pattern

Import Functionality

ExportFunctionality

Traders deal withcomponents or services

Traders are active documents which reason about other active documents

Introspective Active Documents Rely on Semantic Properties

■ Introspective Active Documents have a meta-level architecture, relying on semantic descriptions■ properties, protocol specifications

■ Traders:■ Services described by semantic properties■ Clients specify desired properties■ Traders match desired and offered properties (e.g., by

DOOD technology)■ Traders delegate to other traders if they do not find

matches■ Similar to book management in libraries

Reflective Active Documents (Agents)

■ Agents are automomous active documents which reflect and reason about themselves and their environment ■ have a meta-level architecture with reflective features

■ Splitt-off self agents are agents that represent a human being and represent him for tasks■ Buying things automatically■ Finding interesting people to meet

■ www.agentlink.org

Wearables)

Reflective(Agents)

MobileReflective

Agents

How Do We Build Such Systems?

■ These systems will be complex■ They will migrate■ They will contact other unknown documents■ They will negotiate

■ Reuse of components of active documents would be nice...

■ Semantics is an issue...

■ Activeness is an issue...

Active Documents are Software

Active documents are Software!

Apply Software Engineering Techniques!

But how does Software Engineering look like today?

What Does Software Engineering Look Like Today?

The Essence of the 60s-90s:LEGO Software

■ Modular Systems■ Object-oriented Technology and Design Patterns■ Component-based Programming (CORBA,

DCOM, Beans)■ Architecture languages

Now: paradigm shift towards composition systems

Classical Component Systems

CORBADCOMBeans/EJB

Architecture Systems

Aspect Systems

Systems with Composition Operators

Composition Systems

AesopDarwin

Aspect/J

N-calculus

Meta-object compositionInvasive Composition

Standard Components

Architecture as Aspect

Aspect Separation

CompositionOperators

CompositionLanguage

Object-Oriented Systems JavaC++Sather

Objects asRun-Time Components

Modular Systems Ada-85ModulaC..

Modules as Compile-Time Components

Uniform Composition Systems EASYCOMP

Composition FiltersHyperslices

Where Are We Today?

Component systems (CORBA, DCOM, Beans, OO-frameworks) provide a communication and

standard service infrastructure

components ... but nothing more

LEGO Software

ComponentConnector Component

Interface

Software Architecture Systems

ConnectorsPorts

1make, shell

Composition connectors

pipe, tee, file

Filter Components

Component-based applications

Black-boxcomposition

Connector-basedProgramming

The Essence of the Last 5 Years

■ Aspect-oriented Programming■ View-based Programming

Darwin

CORBADCOMBeans/EJB

Composition Systems

N-calculus

Standard Components

CompositionLanguage

Aspect Systems Aspect/JAspect Separation

StructureInterfaces

Light Plan

Pipe Plan

Integrated House

Debugging

aspect

Debugging

aspect

Persistence

aspect

Persistence

aspectAlgorithmAlgorithm

Debugging aspect

Persistence aspect

Persistence

aspectDebugging aspect

Weaver-ToolWeaver-Tool

Debugging aspect

1Composition

recipe

Weaver

Components

System constructed in a component- and

composition-based architecture

Aspect-oriented

composition

View-basedcomposition

Entering the Era of Composition: The Essence of the 2000s

■ Composition Systems with Composition Language

■ Uniform Composition Systems■ Everything will be an active

component/document■ Software and documents will be composed

uniformly with composition operators and languages

1Composition

recipe

Composition Language

Components

System constructed in a composition-based

architecture

Invasivecomposition

Uniformcomposition

CORBADCOMBeans/EJB

Aspect Systems

AesopDarwin

Aspect/J

Composition Filters

N-calculus

Hyperslices

Standard Components

Aspect Separation

Composition Systems

CompositionLanguage

Uniform Composition Systems

EASYCOMP

Requirements for Uniform Composition: Easy and Powerful

■ Uniform composition of software and data with XML as basis■ security

■ Easy system construction by simple composition technology

■ Architecture■ Reuse compositions from libraries and languages■ Aspect orientation ■ Extensibility and integratability

■ Powerful system construction■ Semantics for compositions in XML■ Reflection, introspection

Invasive Composition - a Uniform Composition Technique

Composition

Component Model Composition Technique

Composition Language

Invasive Composition

Invasive Composition adapts and extends

componentsat hooks

by transformation

1. The Component Model of Invasive Composition

■ The basic element is a fragment box■ a set of fragments/tag elements

■ May be the representation of ■ an XML page■ a XML site■ a software component■ a class, a package, a method■ an aspect■ a meta description■ a composition program

Boxes have Hooks

Hooks are arbitrary elements or spotsof the representation of a boxwhich are subject to change

■ XML Variation Points■ beginning/end of tag lists■ anchors

■ Software Variation Points■ method entries/exits■ generic parameters

Implicit Hooks

Example Method Entry/Exit

abc.. cde..

Method.entry

Method.exit

Given by the programming language, the DTD or Xschema

Declared Hooks

Declarations

Declared Hooks are declared by the box writer as variables in the hook’s tags.

XSuperClass

class Set extends genericXSuperClass { }

class Set /* @superClass */

Declaration of Hooks

■ Markup Tags■ Language Extensions (keywords..)■ Standardized Names■ Comment Tags

2. The Composition Technique of Invasive Composition

A composer is a tag transformer from unbound to bound hooks

composer: box with hooks --> box with tags

Invasive Composition adapts and extends

componentsat hooks

by transformation

List Entry List Entry

LIST ExitList Exit

box.findHook(„Entry“).extend(„<LI>... </LI>”);

box.findHook(„Exit“).extend(“<LI>... </LI>”);

Method Entry Method Entry

Method ExitMethod Exit

abc.. cde..

m (){ print(“enter m”); abc.. cde.. print(“exit m”);}

box.findHook(„.Entry“).extend(“print(\”enter m\”);”);

box.findHook(„Exit“).extend(“print(\”enter m\”);”);

Composer

Invasively transformed tags

■ Invasive Composition works uniformly over code and data

■ Allows to compose active documents uniformly (stationary, shippable, introspective, reflective)

Invasive Composition

3. The Composition Language of Invasive Composition

■ Using standard languages and XML itself■ Java or others

■ Meta-composition possible■ Composition of composition programs

COMPOST –The Invasive Composition System

■ First system to support invasive composition ■ Composition language Java

■ Library of static meta-programs■ Reified concepts Boxes, Hooks, Composers■ Names & Types■ Parsers + pretty printers■ Composers

■ Refactorings■ Inheritance operators■ Connectors■ Aspects

COMPOST for Everybody

■ 0.74 is out (Uni Linköping/Uni Karlsruhe)

http://i44w3info.uni-karlsruhe.de/~compost.htmlhttp://www.ida.liu.se/~uweas/compost-distributions

■ COMPOST is still on Level 7, but extended in EASYCOMP...

The EASYCOMP Project

EASYCOMPs Goal

■ Provide a uniform composition technology (Level 8)

■ Easy■ Powerful

■ EU IST FET Basic Research Project■ 6/2000 - 5/2003 ■ 2.5 Mio Euro Funding■ U Karlsruhe (coordinator), U Hagen, U Linköping,

Ecole des Mines Nantes, TU Vienna, U Twente■ HEI Mannheim, QLABS Paris, ILOG Paris

EASYCOMP Workplan

■ Core composition operator library■ Composition tools for XML active

components■ Component specifications■ Consistency checkers

■ Aspect Composition■ Event-based AOP

■ Case studies in ■ Multimedia learning■ E-commerce■ Dynamic reconfiguration

EASYCOMP -Composition of Active Documents

■ Uniform component model UNICOMP ■ Generalized parameter model hooks■ Uniform composition operators

■ Component models for■ XML components

■ XHTML, HeiTML, SVG, SMIL,..■ Software components

■ Java, C, ...■ Build on top of a XML refactorer and Java

refactorer

UNICOMP Architecture

JavaRecoder

X-HTMLRecoder

JDRUMS

FragmentComponents

Run TimeComponents

Components(Boxes)

PIKERecoder

UNICOMPComponents

.... ....

AbstractComposition

Interfaces forexchange andchecking

Languagespecific

Timespecific

FragmentComponents

EASYCOMP Component and Composition Specification

■ Component properties in DAML■ Composition validation with DAML www.daml.org ■ Generic Semantics with DAML

Outlook on 2005

■ Uniform XML composition technology■ Tooling■ Components■ Semantic descriptions

■ Simplified construction of Active Documents■ Reuse, Extensibility, Aspect separation■ Composition language■ Reflection

■ Web Sites, Active Paper, Wearables, Traders, Agents easier

PIKE Composition

■ PIKE refactorer■ based on static metaprogramming

■ Composition programs in PIKE■ composition library■ connectors, parameterizers, extenders

■ Extension of the language?

The End

■ www.easycomp.org■ www.ida.liu.se/~uweas■ http://i44www.ipd.info.uni-karlsruhe.de/~compost

Easy Composition of

XML-based Active Documents

Uwe Assmann

Linköping University, Sweden

EASYCOMP Consortium

Wearables)

Reflective(Agents)

MobileReflective

Agents

CORBADCOMBeans/EJB

Aspect Systems

Composition Systems

AesopDarwin

Aspect/J

N-calculus

Standard Components

Aspect Separation

CompositionLanguage

EASYCOMPs Goal

■ Provide a uniform composition technology (Level 8)■ Easy■ Powerful

■ EU IST FET Basic Research Project■ 6/2000 - 5/2003 ■ 2.5 Mio Euro Funding■ U Karlsruhe (coordinator), U Hagen, U Linköping,

Ecole des Mines Nantes, TU Vienna, U Twente■ HEI Mannheim, QLABS Paris, ILOG Paris

EASYCOMP Workplan

■ Core composition operator library■ Composition tools for XML active

components■ Component specifications■ Consistency checkers

■ Aspect Composition■ Languages, graph rewriting for automized weaving■ Event-based AOP

■ Case studies in■ Multimedia learning, E-commerce, E-house

■ Composition Ontology

THE END

■ www.easycomp.org■ www.ida.liu.se/~ uweas■ i44w3.ipd.info.uni-karlsruhe.de/~ compost