Adaptation Description Language, Past and Present Directions.

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Adaptation Description Language, Past and Present
Directions.

• Ravi Konuru, IBM

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Web Applications, Producers, Consumers and User
Agents
Producers
Consumers (or integrators)
Clients
Legacy Web App
Application Back End Services
WSXL service
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The Scope
Users
Consumer
Producers
Legacy Web App
WSIA Proxy
HTTP(SOAP)
WSIA Service
WSIA Runtime
Travelers Check Application
WSIA Proxy
Business Logic Web Service
HTTP(HTML)
HTTP(SOAP)
Stock Application
WSIA Service
WSIA Application
WSIA Runtime
WSIA Runtime
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Adaptation Language Requirements

• R1. Reasonable evolution model The methodology,
  the technical effort by a provider to make an
  existing web application into an adaptable WSIA
  service must be reasonable.
• R2. Low Entry Point wrt Computation and
  Scalability The minimum computational and
  scalability demands that are placed on the
  provider must be reasonable.
• R3. Allow for Consumer-Customer Confidentiality
  Consumer to adapt a providers output in a manner
  that is confidential between the consumer and the
  end-user. For example, it is possible for a
  consumer to insert additional markup into the
  output stream without provider having access to
  the inserted markup.  
• R4. Allow for Provider support for adaptation It
  is possible for a provider to provide support and
  perform the adaptations needed by the consumer so
  as to allow a low-entry consumer or for complex
  adaptations.
• R5. Choice of adaptation implementation models A
  single consumer can use a combination of
  available provider operations and local execution
  to achieve a desired set of adaptations.
• R6. Adaptation Description is available
  statically for design-time use.
• R7. Adaptation constraints can be specified by a
  provider.

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Example of Client ? WSXL Service Interaction with
Customization and Adaptation
Aggregation Component (Consumer)
Service Component (Producer)
User
Creates customized instance
createInstance( customization properties )
I
I
P
Allocate new Customized Instance
Views WSIA Instance
getOutput
A
I
S
I
I
Generate Markup, (opt adaptation desc)
Consumer markup adaptation
S
A
Clicks Action
Action Adaptation
I
S
A
I
A
I
S
A
S
Action Handling (opt create Session)
performAction
Local implementation or redirection of action to
other Producer
A
I
S
performAction
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Rest of the Talk

• Part I WSXL Adaptation Language in Position
  Paper
• Part II New work in progress.

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Part I Adaptation Description Language

• Part I Adaptation Description Language
• Position paper version.

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Adaptation Language Position paper version

• Based on the core idea of adaptation points.
• An adaptation point is a point of observation or
  manipulation exported by a producer to enable
  consumer adaptation.
• Adaptation points can provide information
  regarding
• Content (e.g the price of a certain item)
• Look and feel (e.g font attribute for a certain
  table)
• Behaviour (e.g a handler for a click event)
• Related Adaptation points can be grouped under
  Adaptation groups.
• Adaptation group is the root of an adaptation
  description.

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Adaptation Point

• An application-specific Adaptation Point name
• The kind of operation (insert, replace, lookup).
  Specifies the adaptations intended use.
• The names of pages/states, i.e., to the different
  components outputs, that it applies to.
• An extensible locator to the items of interest
  in the output. For instance, xpath, xquery are
  used for XML documents. Note that a locator can
  point to multiple locations in document.
• An Adaptation Point category (XML, CSS, etc).
  Specifies the category of the items of
  interest.
• The information specific to the application of an
  adaptation of that category (XML, CSS).
• Adaptation Generator mechanism for specifying
  provider support
• Tooling Info/Hints.

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Example 1. Look and Feel Adaptations

• ltadaptationGroup name"LookAndFeel"allOrNone"fals
  e"gt
• ltpageNameListgt selector result detail error
• lt/pageNameListgt
• ltcommentgtChange look and feel of FastMem pages
• lt/commentgt
• ltCSSAdaptation name"changeFont" use"override"gt
• ltlocator name"fontStyleLocator typexpath
  value"//div_at_adaptationMarker'changeFont'/_at_styl
  e"/gt
• ltpropertygt font lt/propertygt
• ltcommentgtAdapt the size of the font used on this
  page lt/commentgt
• lt/CSSAdaptationgt
• lt/adaptationGroupgt

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Example 2. Data Value Lookup and Replace

• ltadaptation name"CustomerNumber" usereplace"gt
  
• ltlocator typexpath value_at_/xhtml/body/
  table/row/customer"gt ltXMLAdaptationgt
• ltvalidTypesgtintegerlt/validTypesgt
  lt/XMLAdaptationgt
• lt/adaptationgt

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Example 3. Replace a presentation element

• ltadaptation name"ContactInfo" use"replace"gt
• ltlocator name"ContactLocator" type"xpath"
  value"//cntctInfo"/gt
• ltXMLAdaptationgt
• ltvalidTypegt ShortContactInfo
  LongContactInfo lt/validTypegt
  ltschemaLocationgthttp//www.itsme.com/TypeInfo.xml
  lt/schemaLocationgt
• lt/XMLAdaptationgt
• lt/adaptationgt

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Adaptation Generator

• AdaptationGenerators are operations implemented
  by provider
• Introduced to handle three kinds of situations
• For providers to provide assistance in creating
  markup for the aggregator for use in adaptation.
• To retain control over markup fragments
  inserted/modified.
• To sidestep the limitations of the constraint
  language.
• The operations can be provider specific.
• A provider implements these AdaptationGenerator
  operations and includes their names suitably in
  the adaptation description.
• Invoked by a client to perform presentation and
  data related transforms and use the resulting
  message in performing the adaptation.

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Example 4. Consumer using Provider support.

• Provider implements an operation named
  "addColumnToTable"
•  ltAdaptationGroup nameaddColumnToTableAgt
• ltadaptation nameTableAKey uselookupgt
• lt/adaptationgt
• ltadaptation name"addColumnAtEndOfTableA"
  use"replace"gt
• ltlocator name"TableALocator"
  type"xpath" value"//..."/gt
• ltAdaptationGeneratorgt
  addColumntoTable
• lt/AdaptationGeneratorgt
• lt/adaptationgt
• lt/AdaptationGroupgt
• Signature obtained from providers WSDL, two part
  input message
• a) Portion/ID of original message sent down by
  the provider
• b) Consumers presentation and/or content
  adaptation information

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Part II Work in progress

• Unify the models and mechanisms for
• Customizations executed by the consumer
• Customizations executed by the provider.
• A single ADL that can be used for both.
• Extend ADL to
• support coordination
• support orchestration
• Other Specification requirements
• Proportional to customization complexity.
• Extensible to additional output types.