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XML and Web Services In The News - 25 April 2006
Provided by OASIS |
Edited by Robin Cover
This issue of XML.org Daily Newslink is sponsored by Innodata-Isogen
HEADLINES:
Pipestreaming Microformats: Moving XML from One State to Another
Dethe Elza and David Mertz, IBM developerWorks
The pipes and streams metaphor is very successful in UNIX, and can
apply with varying degrees of success to many other systems. It's
available, in one form or another, in most programming languages and
operating systems. In XML usage, the most common form of pipes and
streams processing is SAX Filters. As most readers of this column know,
SAX is the Simple API for XML. It is a stream-based API, parsing XML
and calling event handlers as significant events (like opening or
closing an element) occur during the parse. Since SAX processing does
not have to maintain state or build a huge data structure (like the
DOM),
it is commonly used for XML tasks which operate on large data sets
(hard to fit in memory), need to be very fast, or are sparse; only
select parts of the XML data is used and the rest is ignored. Streams
are a concept related to pipes: they are what the pipes operate on.
The idea of a stream is that a program doesn't have to have all the
data available before it can start working; this lets it work on data
as it is generated, data coming over a network, or files too large to
fit in memory. This article provides a survey of relevant tools, specs,
and libraries.
Microsoft Plans System Center Service Desk, Virtual Manager
Paula Rooney, CRN
Microsoft has unveiled its rebranded Systems Center Configuration
Manager 2007 and Systems Center Operations Manager 2007 as expected
and touted plans to offer a System Center Service Desk and
virtualization manager. The System Center Service Desk is a "new
member of the System Center family and a product that pulls
[management] all together"; Bob Muglia specifically highlighted the
progress Microsoft is making in its Dynamic Systems Initiative (DSI) --
a commitment to help customers achieve higher business value through
automation, flexible resource utilization and knowledge-driven
processes -- including the Distributed Management Task Force (DMTF)
acceptance of the Web Services for Management (WS-Management)
specification as a preliminary standard and the intention to build a
service desk offering that will serve as a key foundational piece for
the System Center family of solutions. Microsoft also unveiled its
newly named Windows PowerShell object-oriented Unix-like command shell
and scripting language, formerly code named "Monad." The PowerShell
will be available as a Web download later this year and integrated
into a version of Windows in the next two to four years; exchange 2007
and System Center Operations Manager 2007 will be built on PowerShell.
See also: the interview
Danish IT Architecture Committee and SAML 2.0
Staff, eGovernment News
The Danish IT Architecture Committee has decided to stand firm on
SAML 2.0 as the recommended standard for federation. The OASIS ratified
SAML 2.0 standard has since April 2005 been the officially recommended
standard for federation in the Danish public sector. Microsoft's recent
decision to ship a federation service, as part of its Windows 2003
server operating system without supporting the SAML 2.0 standard
challenges this recommendation because the WS-Federation specification
implemented by Microsoft cannot interoperate with SAML 2.0. Denmark
thinks Microsoft should support customer choice by implementing support
for SAML 2.0 in their operating system on equal footing with the
WS-Federation specification. Basing e-government on privately
controlled specifications that may stifle innovation is not desirable
from the Danish point of view. As a consequence the Danish IT
Architecture committee has decided to stand firm on the SAML 2.0
recommendation. At the same time the committee has decided to try and
work towards convergence in the area of federation standards through
dialogue with EU, other governments, suppliers and standardizations
bodies.
See also: SAML references
OpenSAML 2.0, Java Edition, Technology Preview 1
Chad La Joie, WOIS-Middleware Announcementg
An announcement has been issued for the release of OpenSAML 2.0, Java
Edition, Technology Preview 1. This release features: (1) the ability
to parse, marshall, unmarshall, and build SAML 1.0, 1.1, and 2.0
messages; (2) metadata caching and filtering; (3) new documentation;
(4) the ability to work with XML fragments, taking part of a SAML
message and sticking it into another DOM document.... like a SOAP
header or body). This release is not desceibed as production level code but
does represents what the developers believe to be to the final design
of the library for the components mentioned here. OpenSAML is a set of
open-source libraries in Java and C++ which can be used to build,
transport, and parse SAML messages. OpenSAML is able to store the
individual information fields that make up a SAML message, build the
correct XML representation, and parse XML back into the individual
fields before handing it off to a recipient. OpenSAML supports the SOAP
binding for the exchange of SAML request and response objects
(C++ supports requesting only). It provides additional help in
supporting the SAML browser/POST profile for web single sign-on. It
does not currently provide any additional support for the artifact
profile, but provides the machinery needed to implement it in other
software. All core SAML constructs are now supported to some degree.
See also: sources
XML Automaton
Tim Bray, ongoing blog
Tim Bray, co-editor of the Extensible Markup Language (XML)
specification, talks about Lark: "In December of 1996 I released a
piece of software called Lark, which was the world's first XML
Processor -- as the term is defined in the XML Specification. It was
successful, but I stopped maintaining it in 1998 because lots of other
smart people, and some big companies like Microsoft, were shipping
perfectly good processors. I never quite open-sourced it, holding back
one clever bit in the moronic idea that I could make money out of Lark
somehow. The magic sauce is a finite state machine that can be used to
parse XML 1.0. Recently, someone out there needed one of those, so I
thought I'd publish it, with some commentary on Lark's construction
and an amusing anecdote about the name. Lark was a pure deterministic
finite automaton (DFA) parser, with a little teeny state stack.
DFA-driven parsers are a common enough design pattern, although I think
Lark is the only example in the XML space. There are well-known parser
generators such as yacc, GNU bison, and javacc, usually used in
combination with lexical scanners such as flex so that you can write
your grammar in terms of tokens not characters. Also, they handle LALR
langauges, so the parsing technique is quite a bit richer than a pure
state machine. I thought I had a better idea. The grammar of XML is
simple enough, and the syntax characters few enough, that I thought
I could just write down the state machine by hand. So that's what I
did, inventing a special-purpose DFA-description language for the purpose.
See also: Jelliff's update
CNET Editors' Review: Google Calendar Beta
Elsa Wenzel, CNET News.com
The Google Calendar beta is a straightforward, dynamic online
appointment book that can keep you up-to-date with your own private
schedule as well as those from other users and public events. The
advantages of Google Calendar beta over the industry-leading Yahoo
Calendar are its open architecture, RSS support, and integration with
Gmail. The AJAX-based Google Calendar beta offers the potential for
you to mash it up with other data sets to your liking, as fans of
Google Maps have done. An open API isn't available (yet) for Yahoo
Calendar. Google Calendar beta works with XML, iCal, and CSV standards.
Its XML capabilities leave the door open for scheduling possibilities.
For example, rather than slotting in events only from the vendor's
properties (Yahoo Calendar includes only items from its own services,
such as Upcoming.org, Yahoo Groups, Sports, and Finance), Google
Calendar has the potential for you to be able to integrate events from
any number of sources, such as blogs. Google Calendar's ability to
detect potential appointments within the text of Gmail messages sets
it apart from competitors. And the potential for savvy users to add
more features to this open-code beta leaves us wondering what to
expect next from Google Calendar.
ActiveBPEL Rapidly Adds Enterprise Upgrades
Vance McCarthy, Integration Developer News
An upgraded ActiveBPEL Business Process Execution Language engine is
now
available for free download. Upgrades to ActiveBPEL (Milestone 2)
include
XQuery and JavaScript support, as well as a number of other key
ease-of-use direct invocation of other BPEL featuress for devs to get
into business process projects for web services. ActiveBPEL (Milestone
2)
also supports Tomcat 5.5 and Java 1.5, as well as adds support for web
services standards WS-Addressing and WS-Policy, with support for
WS-Security and WS-ReliableMessaging, due for a later release. The
ActiveBPEL engine is written in Java, and runs in any standard Java
servlet container such as Tomcat. It reads BPEL process definitions
(and other inputs such as WSDL files) and creates representations of
BPEL processes. When an incoming message triggers a start activity,
the engine creates a new process instance and starts it running. The
engine takes care of persistence, queues, alarms, and many other
execution details. The ActiveBPEL engine comes from the Open Source
ActiveBPEL project, an organization created by Active Endpoints, Inc.
ActiveBPEL is licensed under the GNU General Public License (GPL).
The Beginning of AJAX Standardization
Pawel Glowacki, eWEEK
A few weeks ago, the first working draft of the XMLHttpRequest Object
specification was published. The beginnings of this standard may have
huge implications for AJAX and Atlas programmers. This is an important
step for highly interactive Web applications to become mainstream, and
it's part of a wider W3C initiative to standardize Web APIs. The
XMLHttpRequest object is an interface exposed by Web browser's
scripting
engine to perform HTTP client functionality. The W3C Web API Working
Group is chartered to develop standard APIs for client-side Web
Application development. This work includes both documenting existing
APIs (such as XMLHttpRequest) and developing new APIs to enable richer
Web Applications. In addition to working on an API specification for
HTTP functionality, the group is also putting its attention on other
specifications that cover different areas of a web browser
functionality.
These include the client interface (the "window" object), DOM Level 3
events and timed events, other network communication methods,
persistent
storage on the client, the DOM Level 3 XPath, drag and drop operations,
monitoring the progress of resources as they are downloaded, and file
upload. Another Working Draft that was recently released is Window
Object 1.0. This specification defines the Window object, which
provides the global namespace for web scripting languages, access to
other documents in a compound document by reference, navigation to
other locations, and timers. The Window Object draft is a very early
one, as it contains lots of placeholders, but the structure is there.
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