Cover Pages: XML Daily Newslink: Tuesday, 10 April 2007

A Cover Pages Publication http://xml.coverpages.org/
Provided by OASIS and Sponsor Members
Edited by Robin Cover

This issue of XML Daily Newslink is sponsored by:
Primeton http://www.primeton.com

Headlines

QuickStudy: Darwin Information Typing Architecture (DITA)
The Roots of WS-Coordination
W3C Last Call: Semantic Annotations for WSDL and XML Schema
OASIS Creates Discussion List for Document Standards Interoperability TC
Taxpayer Advocate Backs IRS E-File Portal Concept
James Clark on XML and JSON
Create a Multi-Section Atom Collection or Feed
How To Deliver Composite Applications with Java, WS-BPEL, and SOA

QuickStudy: Darwin Information Typing Architecture (DITA)
Russell Kay, ComputerWorld

DITA uses XML as the basis for designing, writing, managing and publishing many kinds of information, both in print and on the Web. DITA includes a set of design principles for creating 'information-typed' modules covering specific topics. The adoption of DITA principles facilitates adapting this type of content for a wide variety of delivery vehicles and uses, including integrated help systems, technical documentation, Web-based product-support portals and instructions. A strength of DITA is its ability to be extended to cover new areas of knowledge through specific, targeted document type definitions. DITA is organized around the notion of the topic, defined as a unit of information that describes a single task, concept or reference item, or a chunk of information organized around a single subject. Within the DITA architecture, there are three types of topics: concept, task and reference. These are very useful for complex technical documentation where much of the material falls logically into one of these topic types. To collect and organize references to DITA topics and indicate relationships among topics, DITA uses a simple mapping mechanism. DITA maps can identify the topics in a document and create tables of contents and related links. Maps can organize topics into hierarchies, tables and groups. DITA's extension mechanism allows the use of XSLT and cascading style sheet design features, which many editors and browsers support. Since DITA documents are pure XML, one can use nearly any editor. The DITA Open Toolkit is a set of Java-based, open-source tools that provide a reference for processing DITA maps and topics.

See also: DITA references

The Roots of WS-Coordination
Ian Robinson, Weblog

The WS-Transaction architecture is a Web services evolution of the Activity service, focusing on the interoperable context and Web service messages that flow between coordinator and participant. WS-AT and WS-BA each essentially describe an HLS, defining a transaction-model-specific set of messages. WS-Coordination fulfils the role of the container-provided Activity service, defining the interoperable XML CoordinationContext and the means for participants to be registered with an Activity. The focus of WS-Transaction is the interoperability between coordinators and participants in different systems; consideration of intra-process separation between the transaction service provider itself and the runtime (application-hosting) container and/or hosted applications is a domain-specific detail that is outside the scope of the Web service specifications. As a result, the WS-Transaction specifications do not define any equivalent of the HLS SignalSet interface nor do they define a generic mechanism for producing and consuming a single (extensible) typed Signal. Instead the WS-Transaction architecture requires each transaction model-specific protocol specification (such a WS-AT and WS-BA) to define its own set of XML protocol messages along with coordinator and participant WSDL portTypes to consume these messages. In common with Activity service HLS's, individual WS-Transaction protocol specifications are at liberty to define model-specific interfaces/protocols to enable applications to demarcate transaction boundaries. WS-AT, for example, defines a Completion portType and protocol through which an application can request the completion of an AT transaction (which then causes the 2PC protocol to be initiated with the registered participants).

See also: the specification

W3C Last Call: Semantic Annotations for WSDL and XML Schema
Joel Farrell and Holger Lausen (eds), W3C Technical Report

W3C's SAWSDL Working Group has released a Last Call Working Draft for "Semantic Annotations for WSDL and XML Schema." This version has been published to give an opportunity to the community to review the new namespace for SAWSDL. The Working Group plans to request to move to W3C Proposed Recommendation shortly after the end of the Last Call period; comments are due by 01-May-2007. Semantic Annotations for WSDL and XML Schema (SAWSDL) defines how to add semantic annotations to various parts of a WSDL document such as input and output message structures, interfaces and operations. The extension attributes defined in this specification fit within the WSDL 2.0 and WSDL 1.1 extensibility frameworks. For example, it defines a way to annotate WSDL interfaces and operations with categorization information that can be used to publish a Web service in a registry. The annotations on schema types can be used during Web service discovery and composition. In addition, SAWSDL defines an annotation mechanism for specifying the structural mapping of XML Schema types to and from an ontology such mappings could be used during invocation, particularly when mediation is required. To accomplish semantic annotation, SAWSDL defines extension attributes that can be applied both to WSDL elements and to XML Schema elements. Semantic annotations are references from an element within a WSDL or XML Schema document to a concept in an ontology or to a mapping. This specification defines annotation mechanisms for relating the constituent structures of WSDL input and output messages to concepts defined in an outside ontology. Similarly, it defines how to annotate WSDL operations and interfaces. Further, it defines an annotation mechanism for specifying the structural mapping of XML Schema types to and from an ontology by means of a reference to a mapping definition. The annotation mechanism is independent of the ontology expression language and this specification requires no particular ontology language. It is also independent of mapping languages and does not restrict the possible choices of such languages.

See also: the Usage Guide

OASIS Creates Discussion List for Document Standards Interoperability TC
Staff, OASIS Announcement

OASIS staff announced the formation new discussion list regarding a possible new OASIS Document Standards Interoperability Technical Committee. "One of the benefits that XML touted from early in its inception was that of platform independence. This independence greatly helped in its widespread adoption, yet brought with it the unintended consequence of a proliferation of standardized XML grammars. Document standards such as DITA, DocBook, and ODF address a similar need to mark up documentation in a platform-independent format. Increasingly, organizations need to collaborate and share content with other organizations. As a result, XML interoperability between these standards is critical. These standards, however, have not been designed with cross-standard interoperability in mind. The Doc Standards Interoperability TC is intended to address the development and documentation of scenarios for cross-standard content sharing; a specification for an interoperability framework, including mappings from participating standard formats to the framework; and requirements on participating standards to improve interoperability." The new discussion list may last up to 90 days.

Taxpayer Advocate Backs IRS E-File Portal Concept
Mary Mosquera, Federal Computer Week

Increasing numbers of technology-savvy filers prepare their tax forms using Intuit's TurboTax or H&R Block's TaxCut software. But when it comes to filing their returns, many of them revert to paper. Of the 37.1 million individuals [in the U.S.] who prepare their taxes on computers, 40 percent, or 14.8 million, submitted their tax returns in paper format. A portion of the population can file free through the Free File Alliance, a group of tax preparation firms that provide their e-filing services free to people whose incomes are less than $52,000. IRS Commissioner Mark Everson said proposals to create a free e-file IRS Web site and require tax practitioners to e-file would put unnecessary stress on the IRS. Everson added that he was concerned that creating an IRS e-file Web portal would create competition between the private sector and the IRS that might undermine confidence in the tax system. Large corporations can e-file directly using the IRS' Modernized e-File system. That system depends on Extensible Markup Language (XML) to identify, store and transmit data. The IRS plans to eventually migrate its 1040 tax forms to the Modernized e-File platform. Some experts say that widespread use of the XML standard would increase competition among tax preparation software makers, and e-filers would not have to pay transmitters, such as Intuit, to batch and deliver their tax returns to the IRS. An IRS portal could act as a catcher's mitt, receiving XML output files from many tax preparation competitors. The IRS might need a push from Congress before it would create a free, direct-file Web portal, Olson said. Both Republican and Democratic chairmen of the Senate Finance Committee have urged the IRS to offer a Web site for free direct filing.

James Clark on XML and JSON
James Clark, Blog

I would like to offer a few thoughts about XML and JSON. Some people focus on the ability for browsers to serialize/deserialize JSON natively. This makes JSON an attractive choice for AJAX applications, and I think this has been an important factor in jump starting JSON adoption. But in the longer term, I think there are two other aspects of JSON that are more valuable. (1) JSON is really, really simple, and yet it's expressive enough for many applications. (2) The data model underlying JSON (atomic datatypes, objects/maps, arrays/lists) is a much more natural model for data than an XML infoset. If you're working in a scripting language and read in some JSON, you directly get something that's quite pleasant to work with; if you read in XML, you typically get some DOM-like structure, which is painful to work with (although a bit of XPath can ease the pain), or you have to apply some complex data-binding machinery. However, I don't think JSON will or should relegate XML to a document-only technology. You can't partition the world of information neatly into documents and data. There are many, many cases where information intended for machine-processing has parts which are intended for human consumption. GData is a great example. The GData APIs handle this in JSON by having strings with HTML/XML content. However, I think the ability of XML to handle documents and data in a uniform way is a big advantage for information of this type... (Additionally:) [a] XML's massive installed base gives it an interoperability advantage over any competitive technology; [b] A range of powerful supporting technologies have been developed for XML. Naturally I have a fondness for the ones that I had a role in developing: XPath, XSLT, RELAX NG; I also can see a lot of value in XPath2, XSLT2 and XQuery...[c] JSON's primitive datatype support is weak; the semantics of non-integer numbers are unspecified. [d] JSON does not have anything like XML Namespaces...

Create a Multi-Section Atom Collection or Feed
Nicholas Chase, IBM developerWorks

The Syfy Portal newsfeed has the potential to contain over 3000 archived news stories. Virtually nobody wants their feed reader to download all of these messages, especially since many of them are several years old. To solve that problem, the Atom specification allows for the necessity to send only a portion of the available information. It takes into account the fact that you don't always want to send all of your data to a requester, and provides a way to make this capability feasible. As feeds move beyond merely announcing new content on somebody's blog and into organizing data, you can easily find situations where you don't want your feed to include all of the available data. This tip shows you how to create an Atom feed that lets users page through it using "next" and "previous" links or buttons. It shows you how to implement this functionality using PHP, but the concepts are the same for any programming language.

See also: Atom references

How To Deliver Composite Applications with Java, WS-BPEL, and SOA
K. Schmidt; G.S. Suresh Raj; P. Balashanmugam; SYS-CON Virtualization

The vast adoption of Java technology by the industry in the past decade is a testament to the power of Java. Development of new applications, services, and components using Java is not going away, but many organizations have progressively moved to the next phase in maturing their IT Infrastructure. This phase is driven by many factors including how businesses operate. There are some technologies that are starting to play a critical role in this phase, for example, service-oriented architecture (SOA) is a key enabler. Java EE technology is a natural service-enabler of existing applications, thereby forming the foundation of SOA. Service-enabled applications create the opportunity to compose functions from disparate and cross-functional applications to model business processes that transcend application and enterprise boundaries. Web Services Business Process Execution Language (WS-BPEL) provides a faster way to compose and orchestrate services by reuse. Java and WS-BPEL complement each other perfectly and provide a solid foundation for integrating services and delivering composite applications. This article will briefly explain what these technologies are and how they can work together to improve developer productivity and business agility. The science of delivering composite applications becomes more of an art when architects try to understand when to switch from Java to WS-BPEL. This decision often determines the agility of the composite application.

See also: the BPEL TC


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