Web Services: I18N

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Web Services I18N

• A progress report, or, are we done yet?

32nd Internationalization and Unicode Conference
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Presenter

• Addison PhillipsGlobalization ArchitectLab126C
  hair W3C Internationalization Core WG

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Agenda

• Web services vs. Internationalization
• Where are we? How did we get here?
• W3C WS-I18N
• SOAP, WS-Policy, and all that
• REST, AJAX, and that Web 2.0 thing
• The other Web services

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About This Presentation

• Web service constraints and capabilities
  Internationalization makes a good use case.
• The classic internationalization model
• Applying the internationalization model to Web
  services
• Why constraints? Why capabilities?

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W3C Internationalization Activity

• W3C WSTF
• Web Services Internationalization Usage Scenarios
• Web Services Internationalization Requirements
• W3C Internationalization Core WG
• WS-I18N (Note track)

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Web Services and Internationalization

• So Web Services are internationalized, right?
• Locale-neutral representation (XML Schema)
• No user interface (machine-to-machine)
• Inherits XMLs rich support for Unicode, language
  tags, and so forth
• Internationalization is the problem of the
  service author, not the provider.

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Programming Paradigms

• Desktop
• Locales in the environment
• Web Application
• Locale-related APIs and state mechanisms
• Web Service???
• Uh

the classic I18N model
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Classic SOAP-RPC Web Services
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WS-Policy

• Define service capabilities and constraints via
  policy assertions.
• Use different features together to get different
  results.
• Services advertise policies consumers specify
  requirements

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What sort of policies for I18N?

• Four Patterns
• Locale Neutral
• Service Determined
• Client Influenced
• Data/Resource Driven

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What does that service do?

• Services generally run in the host locale
• May not be the same as the service provider
• May not give the results the user expects
• No way for the user to control it
• Developers must program services to provide
  international capabilities
• Provide the locale modelprovide for inputs that
  indicate the locale in some (usually proprietary)
  manner
• E.g. Define multiple endpoints for different
  locales
• Provide for localization where appropriatedetermi
  ne the language to use for the interaction
• Providers do nothing for you.

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Web Service Descriptions

• Exchange a locale that is explicitly in the
  service signature.
• No standards exist for doing this
• Strong platform and programming language
  dependency
• Exchange a locale that is implied in the
  services operation.
• Web service descriptions dont convey this
  information.
• Describe how a particular endpoint will work.
• There may be multiple endpoints in multiple
  geographies.

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Invocation

• Language negotiation
• Services still need human readable messages.
• Faults (exceptions, errors) need human readable
  messages.
• Service may retrieve, process, store, or
  otherwise access text.
• Locale negotiation
• Making the service do what the user wants.
• Collation, calendar, text processing, currency,
  routing, addressing, formatting, business rules,
  tax authority, legal requirements, etc.

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Basic Conclusions

• Web services need international preferences
• Personally these are locales
• Web service descriptions need to describe
  policies
• This service runs in the fr-FR locale.
• The requester can tell me what locale to use.
• If you request a locale I dont support, I
  return a Fault message.
• Locale identifiers are needed.
• You can tell me what locale to run in if we can
  agree on what the identifier means.
• Web service discovery needs more
  internationalization.

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Constraints and Capabilities

• Internationalization model describes
  capabilities
• Policy? Runtime locale? Etc.
• Internationalization model describe constraints
• Available locales
• Available resources
• Available language content
• Runtime restrictions

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WS-I18N

• Currently a W3C draft eventual status Working
  Group Note
• Provides for basic internationalization
  properties
• Service locale (via IETF BCP 47 language tags)
• Time zone (via Olsen identifiers)
• Can provide additional, service-specific
  preferences
• Currently via LDML (best choice?)

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Issues

• I wrote it in a day
• Language/locale should be in terms of BCP 47
  language priority lists
• Language/locale negotiation needs to be provided
  for
• Separate language from locale?
• Use LDML?
• http//www.w3.org/TR/ws-i18n/

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Examples
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WS-I18N in SOAP Message

1. lti18ninternational ... Sactor"..."gt
2. lti18nlocalegt locale identifier lt/i18nlocalegt
3. lti18ntimezonegt time zone value lt/i18ntimezonegt
4. lti18npreferences ...gt
5. LDML-based or other locale preferences
6. lt/i18npreferencesgt
7. lt/i18ninternationalgt

locale identifier LDML (BCP47) neutral
default time zone value RFC 822 offset
Olson id
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(continued)

1. lti18ninternationalgt
2. lti18nlocalegten-USlt/i18nlocalegt
3. lti18npreferencesgt
4. ltldmlcollationgt
5. ltldmlalias source"de-DE" type"phonebook"/gt
6. lt/ldmlcollationgt
7. lt/i18npreferencesgt
8. lt/i18ninternationalgt

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WS-I18N in WSDL 2.0

• 1 ltwsdldescription 2 targetNamespace"http//tns
  .example.com/" 3 xmlnstns"http//tns.example.co
  m/" 4 xmlnswsdl"http//www.w3.org/ns/wsdl" 5
  xmlnswsp"http//www.w3.org/ns/ws-policy" 6
  xmlnsi18np"http//www.w3.org/2008/04/ws-i18np"gt
  7 ltwspPolicy xmlid"MyPolicy" gt 8
  lti18npi18n/gt 9 lt!-- omitted assertions --gt 10
  lt/wspPolicygt 11 lt!-- omitted elements --gt 12
  ltwsdlbinding name"MyBinding" type"tnsMyInterfa
  ce" gt 13 ltwspPolicyReference 14 URI"MyPolicy"
  15 wsdlrequired"true" /gt 16 lt!-- omitted
  elements --gt 17 lt/wsdlbindinggt 18
  lt/wsdldescriptiongt

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(continued)

• 7 ltwspPolicy xmlid"MyPolicy" gt
• 8 lti18npi18n/gt
• 9 lt!-- omitted assertions --gt
• 10 lt/wspPolicygt

• lti18ninternationalgt
• lti18nlocalegten-USlt/i18nlocalegt
• lti18npreferencesgt
• ltldmlcollationgt
• ltldmlalias source"de-DE" type"phonebook"/gt
• lt/ldmlcollationgt
• lt/i18npreferencesgt
• lt/i18ninternationalgt

• lti18ninternationalgt
• lti18nlocalegten-US,fr,zh-cmn-Hant-CN
  lt/i18nlocalegt
• lti18npreferencesgt
• ltldmlcollationgt
• ltldmlalias source"de-DE" type"phonebook"/gt
• lt/ldmlcollationgt
• lt/i18npreferencesgt
• lt/i18ninternationalgt

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Schedule

• If you can call it a schedule!
• Likely to be published this year, if we can get
  help completing the document.

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REST the other Web services

• Resource oriented rather than RPC
• Nouns, not verbs
• Light-weight simple path-oriented
• Search-engine friendly
• Often technology behind AJAX and Web2.0
• XmlHttpRequest

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REST and I18N

• Alas, the same problemmaybe more acutely
• AJAX often used to directly update the screen
  (so needs to be preformatted, in proper
  language)
• JavaScript has no locale object or locale model
  (cant control how it does formatting)
• Static user interface determined by a Web
  server, not by local configuration (so might get
  multiple languages on one page)
• No standards whatsoever!

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HTTP Accept-Language

• A poor-mans locale negotiation tool

Accept-Languageen-USq1.0,cmn-Hant-CNq0.8,fr-C
Aq0.6
en
BCP 47 (RFC 4647) Lookup Algorithm
available content
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Time and Time Zone

• Most services are not time zone affected.
• See http//www.w3.org/TR/2005/NOTE-timezone-200510
  13/
• Update pending for this document
• Avoidance usually preferable to using zone data
• but sometimes you need a zone offset
• and sometimes you really need a time zone

Zone Noon GMT, 16 July Noon GMT, 16 Dec
America/New_York 800 (DST) 700
America/Santiago 800 900 (DST)
America/Guyana 800 800
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Building an internationalized REST service

• Use Accept-Language and BCP 47 Lookup to
  negotiate language/locale
• Define custom headers when necessary. Document
  these well.

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The REST URI Path dilemma

• How to find stuff in a REST environment
• example.org host (server)
• /users/ path (taxonomy)
• addison resource (e.g. user id)

http//example.org/users/addison
http//example.org/sports/football/Monarcas_Moreli
a/ players/Luis_Ángel_Landín
http//??.??/sports/football/Monarcas_Morelia/ pl
ayers/Luis_Ángel_Landín
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An Example Amazon S3 Service
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Summary

• WS-I18N
• A work in progress you can contribute to.
• Uses WS-Policy to enable SOAP-based Web services
  with locale and other international preferences.
• REST
• Needs Best Practices better if everyone
  identifies locale, language, and international
  preferences in the same way.
• Needs LTLI?

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Questions? and Comments!