<wsdl:message> (or not)

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ltwsdlmessagegt (or not)
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ltmessagegt What problem is it trying to solve?

• Indicate the data that is sent to or received
  from a service
• Typically the information sent is more than one
  thing
• May contain optional pieces of data or things
  which occur repeatedly
• Each thing is typed
• At least two type systems are common on the Web
  Schema, MIME
• Others must also be supported, e.g. Java

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SOAP 1.2 Data Model
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SOAP 1.2 DM with Attachments / PASWA
Outer Package
SOAP Envelope
Other stuff
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Options for WSDL 1.2

• Leave ltmessagegt
• Doesnt support repeating stuff, optionality etc.
• Type/element split causes binding headaches
• Inline ltpartgt within ltoperationgt
• See proposal by Sanjiva
• Still has many of the problems of ltmessagegt
• Just say input/output of an operation is a single
  complexType or element
• Have to do some sleight-of-hand in the SOAP
  binding
• Basically ltsoapBodygt already has a type (say
  xtBody), and this type would effectively be an
  alternate type
• Non-XSD type systems

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An Approach

• ltoperation namencnamegt
• ltinput complexTypeqname/gt
• ltoutput complexTypeqname/gt
• lt/operationgt
• The type cannot be arbitrary
• Having attributes means you cannot literally
  stuff it in ltsoapBodygt
• We would need to go thru and precisely define
  what subset of complexType is legal and
  acceptable for a variety of bindings
• Use the PASWA-style approach for non-XSD type
  systems
• ltelement namexray typexsdbinary
  xmimeTypeimage/jpeg/
  gt
• ltelement namefoo typexsdbinary
  xjavaTypejavaa.b.C/gt
• Having to name the type sucks

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An Approach 2

• ltoperation namencnamegt
• ltinputgt
• ltcomplexTypegt
• lt/complexTypegt
• lt/inputgt
• ltoutputgt
• .
• lt/outputgt
• lt/operationgt
• Alternatively we can define input as an
  extension of complexType
• ltcomplexType nameinput extendscomplexTypegt
• lt/complexTypegt
• (See next page)

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Syntax

• ltoperation namencnamegt
• ltinputgt
• ltxsdsequencegt
• lt/xsdsequencegt
• (etc.)
• lt/inputgt
• lt/operationgt

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Pros/Cons

• Pros
• Eliminates ltmessagegt/ltpartgt
• SOAP doc/lit binding is immediate
• PASWA style approach for attachments is also
  immediate
• Gives optionality etc. as offered by XSD
• Cons
• Sleight-of-hand for soapBody type
• Second class support for other type systems