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Headlines
DocBook V5.0: The Transition Guide
J. Kosek, N. Walsh, D. Hamilton, M. Smith (eds), Technical Report
Jirka Kosek announced the availability of an updated "howto" DocBook Version 5.0 Transition Guide. The document is targeted at DocBook users who are considering switching from DocBook V4.x to DocBook V5.0. It describes differences between DocBook V4.x and V5.0 and provides some suggestions about how to edit and process DocBook V5.0 documents. There is also a section devoted to conversion of legacy documents from DocBook 4.x to DocBook V5.0. The differences between DocBook V4.x and V5.0 are quite radical in some aspects, but the basic idea behind DocBook is still the same and almost all element names are unchanged. Because of this it is very easy to become familiar with DocBook V5.0 if you know any previous version of DocBook. For more than a decade, the DocBook schema was defined using a DTD. However DTDs have serious limitations and DocBook V5.0 is thus defined using a very powerful schema language called RELAX NG. Thanks to RELAX NG, it is now much easier to create customized versions of DocBook, and some content models are now cleaner and more precise. The Technical Committee provides the DocBook 5.0 schema in other schema languages, including W3C XML Schema and an XML DTD, but the RELAX NG Schema is the normative schema. All DocBook V5.0 elements are in the namespace http://docbook.org/ns/docbook. XML namespaces are used to distinguish between different element sets. In the last few years, almost all new XML grammars have used their own namespace. It is easy to create compound documents that contain elements from different XML vocabularies. The namespace name http://docbook.org/ns/docbook serves only as an identifier. This resource is not fetched during processing of DocBook documents and you are not required to have an Internet connection during processing. If you access the namespace URI with a browser, you will find a short explanatory document about the namespace. In the future this document will probably conform to (some version of) RDDL and provide pointers to related resources.
See also: DocBook V5.x
First Working Draft: Content Transformation Landscape 1.0
Jo Rabin and Andrew Swainston (eds), W3C Technical Report
W3C announced that the Content Transformation Task Force of the Mobile Web Best Practices Working Group released the First Public Working Draft for "Content Transformation Landscape 1.0." This document identifies some issues surrounding the use of transforming proxies in the delivery of Web content. It does not comment on the techniques that cause these issues; it merely identifies them in order to inform the requirements of the Content Transformation Guidelines document. That document is to offer recommendations as to how components of the delivery context can cooperate to achieve, at a minimum, a functional user experience. Discussion of these issues is expected to influence the (future) requirements document for Content Transformation Guidelines. Mobile operators, search engines and others recognize that while the number of mobile friendly Web sites is growing, there will remain a considerable number of mobile unaware and mobile blocking sites. One approach to providing a more satisfactory mobile user experience of mobile unaware and blocking sites is to insert an intermediary in the communications path between the user agent and the origin server. These intermediaries, known as content transformation proxies, adjust HTML pages designed for desktop presentation to provide an enhanced user experience when accessed from a mobile device. In order to avoid blocking behavior and in order to achieve a consistent presentation from Web sites that vary their experience according to the browser type, proxies typically work by masquerading as a specific desktop browser, fetching content and then modifying it before returning it to mobile devices. These transformations include: (1) character encoding corrections, (2) image reformatting and resizing, (3) layout modifications and page segmentation, (4) multi step JavaScript transaction emulation.
See also: the Content Transformation Task Force
RDFa Primer: Embedding Structured Data in Web Pages
Ben Adida and Mark Birbeck (eds), W3C Technical Report
The updated version of "RDFa Primer" provides an introduction to RDFa, a method for structuring data by embedding in XHTML. This version of the RDFa Primer is a substantial update to the previous version, representing several design changes since the previous version was published. Current Web pages, written in XHTML, contain inherent structured data: calendar events, contact information, photo captions, song titles, copyright licensing information, etc. When authors and publishers can express this data precisely, and when tools can read it robustly, a new world of user functionality becomes available, letting users transfer structured data between applications and Web sites. An event on a Web page can be directly imported into a desktop calendar. A license on a document can be detected to inform the user of his rights automatically. A photo's creator, camera setting information, resolution, and topic can be published as easily as the original photo itself. RDFa lets XHTML authors express this structured data using existing XHTML attributes and a handful of new ones. Where data, such as a photo caption, is already present on the page for human readers, the author need not repeat it for automated processes to access it. A Web publisher can easily reuse data fields, e.g. an event's date, defined by other publishers, or create new ones altogether. RDFa gets its expressive power from RDF, though the reader need not understand RDF before reading this document. RDFa uses Compact URIs, which express a URI using a prefix.
Data Sources as Web Services
Kyle Gabhart, XML.com
WSO2 ('WS OH 2') is growing in popularity and the team continues to produce quality products. The WSO2 (a.k.a. Web Services Oxygen Tank) team that has pulled together a platform around Apache SOA projects, producing an application server, ESB, Web 2.0 mashup engine, and more. Most recently, they have released Version 2.1 of the Web Services Application Server (WSAS). The release includes a lot of compelling features, but this article focuses upon WSO2 Data Services—a new feature available in WSO2's WSAS 2.0 platform. The author introduces Data Services, examining their architecture and utilization, and exploring pros and cons of this convenient feature. Data services are standard web services that have been configured within WSAS to map to data source calls to one or more backend data sources. Configuration is captured in XML and can either be performed by hand and uploaded as a complete deployment module, or deployed via the web-based Data Service configuration wizard. Once deployed, these services can either be consumed by other WSAS services or be made available to external clients. Data Services are essentially the SOA-equivalent of the Data Access Object pattern. Granted, Data Services are at a much higher level of abstraction, but they serve a similar role in a layered architecture. They enable higher level services or even client applications to access underlying datasets without regard for the implementation details involved... The heart of any enterprise application is data. Applications provide the ability to view, sort, filter, edit, create, and delete data. In a SOA, access to data is also paramount. Typically this involves wrapping an existing business object (EJB or POJO) with a web service. Another option is to bypass this additional layer and directly expose data capabilities via WSO2 Data Services. Data services are convenient, configurable, and great for service oriented data for a demo or even as a part of a SOA.
Mashups: The Evolution of the SOA
Stephen Watt, IBM developerWorks
This article is first in a three-part series, providing a general overview of the characteristics and technologies related to the term Web 2.0 so that a platform can be laid for a detailed discussion about how they relate to Service-Oriented Architecture (SOA) development. The second part in the series examines the current state of IT and SOA in the enterprise and discusses what situational applications and a mashup ecosystem can offer. The third part describes the IBM Mashup Starter Kit (IBMMSK) and how you can use it to develop situational applications. Web 2.0 is best described as a core set of patterns that are observable in applications that share the Web 2.0 label. These patterns are services, simplicity, and community. This shift to a service-based model has implications for how Web 2.0 applications are now developed. The Web infrastructure is now seen as the bottom of the application development stack.The prevalence of Web APIs lets you avoid the work of creating certain features, thereby reducing your workload so you can build applications faster. In addition, you can integrate two or more of these Web APIs to create something new and unique, known as a mashup. Web-based APIs can then be invoked using technologies, such as Ajax, which provides a means for the browser client to communicate with the server via JavaScript (both synchronously and asynchronously). This means the application doesn't require the entire page to be reloaded every time the client needs to communicate with the server. You can use JavaScript Object Notation (JSON) to serialize and deserialize objects so that they can be sent between the browser client and the server via Ajax. It's now quite common to see existing services provide SOAP, Ajax, and REST interfaces. RSS and Atom feeds have now gone beyond being used only to subscribe to blogs and news feeds, and are seen as potential approaches to simplify specific content-centric application architectures. The Atom specification is a more recent evolution of the ideas originally embodied by RSS and provides useful features, such as the Atom Publishing Protocol (APP), which lets you publish information to be added to a feed. If event-driven architectures are now part of the SOA framework, then feeds can be considered part of the service paradigm and should be leveraged as such.
Growing Pains: Can Web 2.0 Evolve Into An Enterprise Technology?
Andy Dornan, InformationWeek
Wikis, mashups, social networking, and even Second Life can have a place in business, but they need to improve legacy interoperability -- and IT needs to overcome its skepticism. Loss of IT control is a consistent theme as Web 2.0 penetrates business. The greatest upheaval is likely to come from enterprise mashups, which combine the social and technical aspects of Web 2.0 by letting users develop their own applications. Though very few businesses use mashups at present, those that are see great benefits, and larger players such as BEA, IBM, and Oracle are entering the game. Cutting out the middleman—that's the IT department—can be a great way of aligning business and technology. Web 2.0 means more than just SaaS. Though the term is often abused, all the various technologies, products, and sites grouped together as "Web 2.0" do have one thing in common: interactivity. Web 2.0 is designed for two-way communication. At the technical level, it replaces static HTML with JavaScript apps that continually send and receive small chunks of XML or text. At the social level, it means Web sites that let people communicate, not just read or shop. Instead of passive consumers, Web surfers can become active creators. All that interactivity ought to make Web 2.0 ideally suited for business use. Most workplaces are about production, not consumption. However, enterprises lag far behind consumers in adoption of Web 2.0 technologies. What's more, our online poll shows that interest in technologies such as blogs, wikis, and mashups has gone down during 2007, despite explosive growth outside the firewall. Part of the reason is that business users already have access to more sophisticated versions of the same technologies. Blogging is publishing, a wiki is a CMS (content management system), and Ajax is a more standardized way of achieving what many internal enterprise applications already do with ActiveX or Java.
Selected from the Cover Pages, by Robin Cover
Muradora GUI for Fedora Repository Uses SAML and XACML for Federated Identity
The DRAMA (Digital Repository Authorization Middleware Architecture) development team at MELCOE, Macquarie University, Sydney, Australia has announced the release of Muradora Version 1.0, described as a turnkey GUI for the Fedora Repository supporting federated identity and flexible access control. Fedora is a general purpose repository system developed jointly by Cornell University Information Science and the University of Virginia Library. The Fedora Project is devoted to the goal of providing open-source repository software and related services to serve as the foundation for many types of information management systems. The Fedora software is available under the terms of the Educational Community License 1.0 (ECL). Fedora was selected for Muradora because it is widely used, is recognized as scalable (supporting more than one million objects), and has an exxellent digital object model. The project goals are to support collaboration between researchers for access and search across institutional protected repositories, with an easy to use and maintain access control system requiring little or no intervention from system administrators. Muradora incorporates a suite of software modules to deal with the needs for federated identity and flexible authorisation for repositories. Key Muradora modules include Shibboleth (SAML) authentication for federated identity/single-sign-on, a Fedora authorization framework based on XACML, an extended XACML engine using DB XML for policy enforcement, and web service interfaces for XACML requests and responses.
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