This issue of XML Daily Newslink is sponsored by:
- SIMPLE made Simple: An Overview of the IETF Specifications for Instant Messaging and Presence using the Session Initiation Protocol
- APP vs. Web3S: the Quest for a RESTful Protocol
- News Architecture 1.0 (NAR) Officially Adopted by the IPTC
- Call for Presentations: OASIS Open Standards Forum
- Tutorials on Schematron: Rule-Based XML Validation
- GCN Editor's Desk: NIEM's Reach
SIMPLE made Simple: An Overview of the IETF Specifications for
Instant Messaging and Presence using the Session Initiation Protocol
Jonathan Rosenberg (ed), IETF Internet Draft
The IETF has produced many specifications related to Presence and Instant Messaging with the Session Initiation Protocol (SIP). Collectively, these specifications are known as 'SIMPLE: SIP for Instant Messaging and Presence Leveraging Extensions'. This document serves as a guide to the SIMPLE suite of specifications. It breaks them up into categories and explains what each is for and how they relate to each other. Each specification also includes a letter that designates its category in the standards track: [S]: Standards Track (Proposed Standard, Draft Standard, or Standard); [E]: Experimental; [B]: Best Current Practice; [I]: Informational. SIMPLE provides for both presence and IM capabilities. Though both of these fit underneath the broad SIMPLE umbrella, they are well separated from each other and are supported by different sets of specifications. That is a key part of the SIMPLE story; presence is much broader than just IM, and it enables communications using voice and video along with IM. The SIMPLE presence specifications can be broken up into: (1) The core protocol machinery, which provides the actual SIP extensions for subscriptions, notifications and publications; (2) Presence documents, which are XML documents that provide for rich presence and are carried by the core protocol machinery; (3) Privacy and policy, which are documents for expressing privacy preferences about how those presence documents are to be shown or not shown to other users; (4) Provisioning, which describes how users manage their privacy policies, buddy lists and other pieces of information required for SIMPLE presence to work; (5) Optimizations, which are improvements in the core protocol machinery that were defined to improve the performance of SIMPLE, particularly on wireless links.
See also: Presence Information Data Format (PIDF)
APP vs. Web3S: the Quest for a RESTful Protocol
Arnon Rotem-Gal-Oz, InfoQ
Standardizing on a protocol for resource publishing and editing can bring a lot of benefits since it increases the chances for achieving interoperability between parties and universal understanding. While XML as a base format creates brings some of those benefits, it's a little too general to be useful without also setting some widely accepted ground rules for describing more specific attributes like collections and entries. Combining such a format with the generic HTTP protocol in a RESTful promises a common ground. Indeed there are several protocols available that aim to solve this problem. The first and probably most mature is the ATOM Publishing Protocol (APP) which is a draft IETF standard close to finalization. Microsoft has relesed a protocol which called Web3S ("Web Structured, Schema'd & Searchable"). Microsoft's Dare Obasanjo explained some of the problems Microsoft sees with APP which (probably) led to the development of an independent protocol: mismatch with data models that aren't microcontent, lack of support for granular updates to fields of an item, and poor support for hierarchy. IBM's Sam Ruby, co-author of RESTful Web Services, believes the protocol intended to support "Web Structured, Schema'd & Searchable" support neither the Web, Schema, or Search: 'There are two new media types (Application/Web3S+xml and Application/Web3SDelta+xml), two new URI Protocols (Web3S and Web3SBase), and one new HTTP method (UPDATE) defined in this document. I can find no discussion of binary data, in fact everything seems defined in terms of the XML infoset. Given that all data needs to be in a namespace, and that all such namespaces need to use a new URI protocol, one can conclude that no existing XML documents can be directly handled by Web3S. Web3S data is further constrained to be a self enclosed tree. There is no general concept of a hyperlink in Web3S, neither to external data, nor within a tree. To traverse this data, one needs to be aware of the specific schema employed by the application.'...
See also: Atom references
News Architecture 1.0 (NAR) Officially Adopted by the IPTC
Misha Wolf and Laurent Le Meur, IPTC Announcement
IPTC (International Press Telecommunications Council) members have been actively working to complete the framework on which all new IPTC standards, will be based, including NewsML-G2. The IPTC recently adopted the News Architecture 1.0 during its AGM in Tokyo. This is an enormous milestone for the IPTC, the outcome of many person-years of work. The News Architecture framework (NAR) defines four main objects: a newsItem, packageItem, conceptItem, and knowledgeItem. Information about these structures and associated processing model can be found in the approved package available on the IPTC web site. The NAR 1.0 ZIP package contains (1) the model specification of the NAR (Core Model specification 1.0 and the Power Extension specification 1.0); (2) an implementation in W3C XML Schema files, and documentation of the XML Schemas for the five items plus the News Message at the Core Level and the Power Level); (3) a Glossary document for the NAR; (4) supplemental material including a catalog file (XML) with URIs and recommended aliases for IPTC maintained metadata code schemes. The NAR constitutes about 90% of NewsML-G2, [so it is expected] that NewsML-G2 can be finalized before the end of the year. NewsML-G2 specifies an extension of the generic newsItem, when this newsItem is used to represent media objects (textual stories, images or audio clips). Most of the extensions have already been discussed internally by IPTC members, including several large News Agencies plus the European Broadcasting Union (EBU). We hope to work closely with the W3C, to ensure the close integration of the News Architecture, of the standards based on it (such as NewsML-G2), and of the many taxonomies to be used with these standard, with the Semantic Web. The IPTC, based in Windsor, UK, is a consortium of the world's major news agencies, news publishers and news industry vendors. It develops and maintains technical standards for improved news exchange that are used by virtually every major news organization in the world.
See also: the IPTC web site
Call for Presentations: OASIS Open Standards Forum
Staff, OASIS Announcement
OASIS has issued a call for presentations relevant to the Open Standards Forum "Enabling Transitional Government Through Web Services and SOA", to be held October 29-30, 2007 in London, UK. From the text of the CFP: "At the core of many practical implementations that aim to deliver on the vision of "transformational government" are open standards and interoperability specifications. Open standards for information exchange allow government agencies to integrate systems provided by different vendors, built over many years, based on evolving technologies, architectural concepts, business processes and requirements. Standards also permit governments to connect more easily to their citizens, to businesses, as well as internationally to other governments. Delegates responsible for helping define and execute integration projects in the public sector in the UK, Europe, and around the world are invited to join us this fall in London. By participating in this two-day event, you'll gain an understanding of the core structure, concepts and relations in the jungle of WS-* specifications and how to separate mature from immature specifications and standards-based approaches from proprietary vendor specifications."
See also: the web site
Tutorials on Schematron: Rule-Based XML Validation
Roger L. Costello, XML-DEV Posting
In a posting to the XML-DEV list, Roger Costello announced the preparation of new tutorial materials for the Schematron language: "Schematron is an XML-based language for validating XML instance documents. Schematron is used to make assertions about data in an XML document. Schematron is used to express operational and business rules. Schematron is an ISO standard. Use Schematron to verify data interdependencies (co-constraints), check data cardinality, and perform algorithmic checks. A co-constraint is a dependency between data within an XML document or across XML documents. Cardinality refers to the presence or absence of data. An algorithmic check determines data validity by performing an algorithm on the data. Invitation to Contribute: These tutorials teach the core concepts of Schematron. However, there are some aspects that are not covered, such as the use of abstract patterns and rules, 'report' versus 'assert', and performance of the different Schematron tools. I invite you to create a short tutorial on some aspect of Schematron and I will incorporate it here, and, of course, you will be acknowledged as the author. The tutorials are HTML documents. Some of them appear as slide shows (using S5)."
See also: Schematron references
GCN Editor's Desk: NIEM's Reach
Wyatt Kash, Government Computer News
Those with a stake in the evolution of the National Information Exchange Model (NIEM) are likely to be pleased this month with NIEM's first major upgrade since it was introduced a year ago. Yet even those without a direct stake, but for whom information-sharing remains important, might consider a fresh look at what the teams behind NIEM are accomplishing. NIEM is the outgrowth of efforts that took root inside the Justice Department to standardize the Extensible Markup Language (XML) schema used to describe the information commonly used by and exchanged among federal, state and local enforcement agencies. Those efforts led to the Global Justice XML Data Model which laid the foundation for building a vocabulary of metatagging terms with unified, if not universal, meaning. Reconciling the varying definitions and uses of even a single term among different groups remains one of the underlying challenges to advancing the ability to share information. A passport, for example, seems like a pretty straightforward term. But because the many organizations that deal with passport information differ in nature, so do the terms used to describe them. Harmonizing that terminology—along with 4,000 other terms used in support of emergency management, immigration, infrastructure protection, intelligence, international trade and other disciplines—is among the thousands of refinements being incorporated in the new NIEM release. The significance of NIEM goes beyond the data model it is creating. It also serves as a benchmark model for building information-sharing bridges among federal, state and local government agencies. Building an XML schema is no easy task. But NIEM demonstrates not only that it can be done but also how it can be done.
See also: on NIEM Version 2
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