[R5xx] Application of requirements to SOAP 1.1

R500
The specification will make reasonable efforts to support (but not define)
a broad range of programming models suitable for the applications intended
for XP.

The introduction to the SOAP specification states that:
     SOAP provides a simple and lightweight mechanism for exchanging
structured and typed information between peers in a decentralized,
distributed environment using XML. SOAP does not itself define any
application semantics such as a programming model or
     implementation specific semantics; rather it defines a simple
mechanism for expressing application semantics by providing a modular
     packaging model and encoding mechanisms for encoding data within
modules. This allows SOAP to be used in a large variety of systems
     ranging from messaging systems to RPC.
Therefore the SOAP 1.1 specification mainly supports R500.
Issue: There is a common belief that SOAP is intended for, and only
supports the RPC programming model. The XP WG should emphasise the
neutrality of its specification to programming models and illustrate its
applicability to them via a wide range of use cases.

R501
The specification will make reasonable efforts to support (but not define)
a broad range of protocol bindings between communicating peers.

The SOAP 1.1 specification defines a binding to HTTP only. Therefore it
only partially supports requirement R501.

R502
The specification developed by the Working Group must support either
directly or via well defined extension mechanisms different messaging
patterns and scenarios. The specification will directly support One-way and
Request-response patterns as part of permanently and intermittently
connected scenarios. The specification will not preclude the development of
other patterns at either the application or transport layers. Examples of
such patterns may include publish-subscribe or multicast delivery. All
patterns and scenarios will be described by relevant use cases.

The SOAP 1.1 specification partially supports requirement R502. There are
no explicit examples in the SOAP 1.1 specification to support this
requirement. The XP specification must provide a broader set of patterns
and scenarios.

R503
The Working Group will coordinate with W3C XML Activities through the XML
Coordination Group and shall use available XML technologies whenever
possible. If there are cases where this is not possible, the reasons must
be documented thoroughly.

Requirement R503 is a procedural requirement placed on the XP WG and is not
influenced by the SOAP 1.1 specification.

R504
The specification developed by the Working Group shall be as lightweight as
possible keeping parts that are mandatory to the minimum. Optional parts of
the specification should be orthogonal to each other allowing
non-conflicting configurations to be implemented.

The SOAP 1.1 specification provides a lightweight framework with
extensibility via namespace defined header elements. The SOAP Body provides
a mechanism for exchanging mandatory information (Section 4.3). This
provides only part of the extensibility requirements implied by R504.
Therefore the SOAP 1.1 specification partly fulfils R504.

R505
The specification must be suitable for use between communicating parties
that do not have a priori knowledge of each other.

The SOAP 1.1 specification does not support this requirement. At the
minimum, there has to be an implicit assumption that the communicating
parties will understand the SOAP protocol. The protocol does not provide a
mechanism for submitting a SOAP request to a generic HTTP (or other
protocol) server.

R506
The specification must focus on the encapsulation and representation of
data being transferred between parties capable of generating and/or
accepting an XP protocol envelope.

The SOAP 1.1 specification partially fulfils this requirement. It provides
one mechanism for encapsulation and encoding of data with limited examples
of extensibility. The XP specification must broaden these mechanisms via
use cases.


XML Technology and Messaging,
IBM UK Ltd, Hursley Park,
Winchester, SO21 2JN

Tel: (work) +44 (0)1962 815188        (home) +44 (0)1722 781271
Fax: +44 (0)1962 816898
Notes Id: John Ibbotson/UK/IBM
email: john_ibbotson@uk.ibm.com

Received on Wednesday, 31 January 2001 06:03:52 UTC