The Working Group follows the rules and requirements of the latest operative version of the World Wide Web Consortium Process Document. In the event of a conflict between this document and the W3C Process Document, the W3C Process Document shall take precedence.
The mission of this Working Group is to define a set of XML Schema
patterns for representing data structures common to many programming
languages, such as hash tables, vectors, or collections. There are
several ways of representing those data structures and Web Services
toolkits are currently using ad hoc technologies to infer the most
suitable structure when processing XML Schemas. For example, keys from
a hash table can be represented using the ID
derived
type, the xs:key
component, or the xs:unique
component, and possibly in other ways. Mapping common data structures
into known XML Schema patterns will facilitate the binding to
suitable structures when processing XML Schemas, and will also expose
a more comprehensible data model to the programmer.
The Working Group should identify a set of common data structures and define a set of XML Schema patterns for them for the purpose of simplifying the mapping of XML Schemas into programming language structures. Those patterns must be independent of any particular programming language. The Group will also develop a method of identifying the usage of those patterns so that conformance of an XML Schema to those patterns can be verified.
This group will also look at the issue of versioning of data structures and the impact on the XML Schema patterns. For example, suppose a programmer uses one version of a class and a later version of that class adds a new property. The Working Group will examine how such a change might affect Web Services compatibility, and what programmers can do to reduce the risk of incompatibility across versions (e.g,. XML Schema wildcards and lax processing of wildcard content might facilitate migration to a new version, but there are associated costs as well).
As the TAG and other groups have discussed, it is important to consider evolution goals early in the design process. The Technical Architecture Group, the Web Services Description Working Group, and the XML Schema Working Group (see XML Schema Versioning Use Cases) are all studying versioning and extensibility issues. It is therefore expected that this Working Group will follow the results of those discussions.
Profiling XML Schema for Web Services is out of scope: While the patterns are not expected to use every possible feature of XML Schema, Web Services toolkits are expected to provide full support of XML Schema.
We expect this work to unfold in two successive set of patterns:
The expiration date of this charter is 30 September 2007.
The milestones follow the roadmap, outlined above.
The Working Group should coordinate its efforts with the W3C Working Groups involved in the Web Services and XML Activities, in particular the Web Services Description Working Group and the XML Schema Working Group, as well as the Technical Architecture Group.
Various efforts have been accomplished outside W3C in order to map the XML Schema constructions in different programming languages (C#, Java, Python, …). The Working Group will also take those external efforts into account.
Effective participation is expected to consume one workday per week for each Working Group participant; two days per week for editors. The Chair shall ensure that the criteria for Good Standing are understood and followed.
To be successful, we expect the Working Group to have 10 or more active participants for its duration.
The initial Chair of this Working Group is Paul Downey, BT.
The initial W3C Team contact is Yves Lafon. It is expected that this Working Group would consume about 0.2 FTE, including administrative logistics.
The Working Group will have distributed and face-to-face meetings.
The Working Group will use a public mailing list, public-xsd-databinding@w3.org.
A Member-only mailing list member-xsd-databinding@w3.org is also available for administrative purposes only.
The proceedings of this Working Group are public, subject to exceptions made by the Chair, after consultation with the Working Group.
This Working Group operates under the W3C Patent Policy (5 February 2004 Version). To promote the widest adoption of Web standards, W3C seeks to issue Recommendations that can be implemented, according to this policy, on a Royalty-Free basis.