|By Kelvin Goodson, Geoffrey Winn||
|April 10, 2007 03:00 PM EDT||
In Part 1 of this article we introduced SDO, looking at its origins and then reviewing some of its features through a scenario based on medical investigations. In Part 2 we'll go on to examine further features of SDO in such a way as to add property values to a data object beyond those explicitly defined by its type, the ability to record changes made to the data graph, a more elegant way to create types programmatically, and the ability to extend datatypes at runtime.
Our examples will depend on two XML Schema definition files that we'll reproduce here. The full details of the scenario they represent were presented in Part 1. These listings are available at http://gemsres.com/story/dec06/313547/source.html.
Part 1 of this article was published when version 2.01 of the SDO specification was current. Since then v2.1 has been released, however, in this article we'll continue to use version 2.01 for consistency.
Adding Open Content
The scenario begun in Part 1 now unfolds a little further. In particular, we'll examine the addition of values to a DataObject by virtue of the DataObject's type being open; that is to say, the property values in addition to those defined by its type. Joe Johnson has been found to have the rare condition, Panarr Syndrome. The designers of the test's data model have made use of the generic People model described in the first XML Schema from Part 1 and this design decision was only possible because the designer of the People model made the Person type open.
Note how in the schema for the medical test there are two global elements defined, one for the test itself and one for the medical condition. When the schema is read into the SDO runtime, these elements are translated into SDO global properties, scoped in the namespace URI of the schema. They're global properties, because they're not logically part of a type. It's this kind of global property that can be used to add information to an instance of an open type.
Property conditionProperty = XSDHelper.INSTANCE.getGlobalProperty(
"www.example.org/MedicalTest", "condition", true);
DataObject condition = DataFactory.INSTANCE.create(
condition.setString("name", "Panarr Syndrome");
List conditions = person1.getList(conditionProperty);
In this code, SDO's XSDHelper has been used to look up the global property, and the DataFactory has been used to create a DataObject of the appropriate type. The interesting part of this code snippet is that when asked for the list of values associated with the "condition" property of the person DataObject, even though that property doesn't belong to the Person type and was never associated with the Person instance, the call to getList(conditionProperty) resulted in an empty list being created and returned. If the type of Person hadn't been open, this call would have resulted in an exception being thrown. Now we can simply add the condition to the list and any further serialization of this person instance will look like this:
<person gender="male" id="1" name="Joe Johnson Snr.">
<Test:condition name="Panarr Syndrome"/>
It's worth noting that the SDO 2.1 specification adds to the SDO's capability for handling open content metadata and instance data.
Complex Graphs and Non-Containment References
In part 1 we examined one kind of relationship between data objects, that of containment. Every data object other than the root has exactly one parent data object that's its container. However, what if we want to express other relationships? In SDO these are represented by non-containment references.
We've already seen how SDO handles containment. We'll now explore adding complexity to the data graph by using non-containment links. Given the likelihood of members of Joe's family exhibiting Panarr Syndrome we'll add a list of Joe's relatives to the test set:
DataObject relatives = test.createDataObject("relatives");
DataObject person2 = relatives.createDataObject("person");
person2.setString("name", "Joe Johnson Jnr.");
DataObject relation = person1.createDataObject("relative");
This code snippet demonstrates the building of a complex graph using a non-containment link. We've created a new person in the test's set of relatives and made a link to that person from a new "Relative" property value for person1. So now our test looks like this:
<person gender="male" id="1" name="Joe Johnson Snr.">
<relative relationship="child" target="2"/>
<Test:condition name="Panarr Syndrome"/>
<person gender="male" id="2" name="Joe Johnson Jnr."/>
Observe how the target attribute of the relative element has a value of "2," which is the id attribute value of the person "Joe Johnson Jnr" thus establishing the relationship from father to son. Looking back at the schema for Person, note how the use of the XML Schema "ID" attribute in the definition of the Person type and the "IDREF" attribute in the "Relative" type's target element lets us make this non-containment link. Having made the link, SDO needs a bit of help from the schema author to know what kind of value to expect the non-containment link to resolve to and so the "target" attribute is qualified by an sdoxml:propertyType attribute to indicate that any referenced objects will be the type Person.
SYS-CON Events announced today that MobiDev, a client-oriented software development company, will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place June 6-8, 2017, at the Javits Center in New York City, NY, and the 21st International Cloud Expo®, which will take place October 31-November 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. MobiDev is a software company that develops and delivers turn-key mobile apps, websites, web services, and complex softw...
Jan. 17, 2017 04:15 AM EST Reads: 1,779
DevOps is being widely accepted (if not fully adopted) as essential in enterprise IT. But as Enterprise DevOps gains maturity, expands scope, and increases velocity, the need for data-driven decisions across teams becomes more acute. DevOps teams in any modern business must wrangle the ‘digital exhaust’ from the delivery toolchain, "pervasive" and "cognitive" computing, APIs and services, mobile devices and applications, the Internet of Things, and now even blockchain. In this power panel at @...
Jan. 17, 2017 03:45 AM EST Reads: 2,711
Internet of @ThingsExpo, taking place June 6-8, 2017 at the Javits Center in New York City, New York, is co-located with the 20th International Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world. @ThingsExpo New York Call for Papers is now open.
Jan. 17, 2017 03:45 AM EST Reads: 3,525
Web Real-Time Communication APIs have quickly revolutionized what browsers are capable of. In addition to video and audio streams, we can now bi-directionally send arbitrary data over WebRTC's PeerConnection Data Channels. With the advent of Progressive Web Apps and new hardware APIs such as WebBluetooh and WebUSB, we can finally enable users to stitch together the Internet of Things directly from their browsers while communicating privately and securely in a decentralized way.
Jan. 17, 2017 03:00 AM EST Reads: 537
The cloud market growth today is largely in public clouds. While there is a lot of spend in IT departments in virtualization, these aren’t yet translating into a true “cloud” experience within the enterprise. What is stopping the growth of the “private cloud” market? In his general session at 18th Cloud Expo, Nara Rajagopalan, CEO of Accelerite, explored the challenges in deploying, managing, and getting adoption for a private cloud within an enterprise. What are the key differences between wh...
Jan. 17, 2017 12:45 AM EST Reads: 6,016
WebRTC has had a real tough three or four years, and so have those working with it. Only a few short years ago, the development world were excited about WebRTC and proclaiming how awesome it was. You might have played with the technology a couple of years ago, only to find the extra infrastructure requirements were painful to implement and poorly documented. This probably left a bitter taste in your mouth, especially when things went wrong.
Jan. 16, 2017 09:00 PM EST Reads: 7,448
IoT is at the core or many Digital Transformation initiatives with the goal of re-inventing a company's business model. We all agree that collecting relevant IoT data will result in massive amounts of data needing to be stored. However, with the rapid development of IoT devices and ongoing business model transformation, we are not able to predict the volume and growth of IoT data. And with the lack of IoT history, traditional methods of IT and infrastructure planning based on the past do not app...
Jan. 16, 2017 03:15 PM EST Reads: 386
"LinearHub provides smart video conferencing, which is the Roundee service, and we archive all the video conferences and we also provide the transcript," stated Sunghyuk Kim, CEO of LinearHub, in this SYS-CON.tv interview at @ThingsExpo, held November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA.
Jan. 16, 2017 02:30 PM EST Reads: 1,556
With major technology companies and startups seriously embracing IoT strategies, now is the perfect time to attend @ThingsExpo 2016 in New York. Learn what is going on, contribute to the discussions, and ensure that your enterprise is as "IoT-Ready" as it can be! Internet of @ThingsExpo, taking place June 6-8, 2017, at the Javits Center in New York City, New York, is co-located with 20th Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry p...
Jan. 16, 2017 01:45 PM EST Reads: 3,606
"There's a growing demand from users for things to be faster. When you think about all the transactions or interactions users will have with your product and everything that is between those transactions and interactions - what drives us at Catchpoint Systems is the idea to measure that and to analyze it," explained Leo Vasiliou, Director of Web Performance Engineering at Catchpoint Systems, in this SYS-CON.tv interview at 18th Cloud Expo, held June 7-9, 2016, at the Javits Center in New York Ci...
Jan. 16, 2017 12:30 PM EST Reads: 5,495
The 20th International Cloud Expo has announced that its Call for Papers is open. Cloud Expo, to be held June 6-8, 2017, at the Javits Center in New York City, brings together Cloud Computing, Big Data, Internet of Things, DevOps, Containers, Microservices and WebRTC to one location. With cloud computing driving a higher percentage of enterprise IT budgets every year, it becomes increasingly important to plant your flag in this fast-expanding business opportunity. Submit your speaking proposal ...
Jan. 16, 2017 12:30 PM EST Reads: 5,028
Discover top technologies and tools all under one roof at April 24–28, 2017, at the Westin San Diego in San Diego, CA. Explore the Mobile Dev + Test and IoT Dev + Test Expo and enjoy all of these unique opportunities: The latest solutions, technologies, and tools in mobile or IoT software development and testing. Meet one-on-one with representatives from some of today's most innovative organizations
Jan. 16, 2017 12:00 PM EST Reads: 1,425
20th Cloud Expo, taking place June 6-8, 2017, at the Javits Center in New York City, NY, will feature technical sessions from a rock star conference faculty and the leading industry players in the world. Cloud computing is now being embraced by a majority of enterprises of all sizes. Yesterday's debate about public vs. private has transformed into the reality of hybrid cloud: a recent survey shows that 74% of enterprises have a hybrid cloud strategy.
Jan. 16, 2017 11:30 AM EST Reads: 4,163
SYS-CON Events announced today that Super Micro Computer, Inc., a global leader in Embedded and IoT solutions, will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 7-9, 2017, at the Javits Center in New York City, NY. Supermicro (NASDAQ: SMCI), the leading innovator in high-performance, high-efficiency server technology, is a premier provider of advanced server Building Block Solutions® for Data Center, Cloud Computing, Enterprise IT, Hadoop/Big Data, HPC and E...
Jan. 16, 2017 11:30 AM EST Reads: 5,694
SYS-CON Events announced today that Linux Academy, the foremost online Linux and cloud training platform and community, will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Linux Academy was founded on the belief that providing high-quality, in-depth training should be available at an affordable price. Industry leaders in quality training, provided services, and student certification passes, its goal is to c...
Jan. 16, 2017 11:30 AM EST Reads: 1,893
WebRTC is the future of browser-to-browser communications, and continues to make inroads into the traditional, difficult, plug-in web communications world. The 6th WebRTC Summit continues our tradition of delivering the latest and greatest presentations within the world of WebRTC. Topics include voice calling, video chat, P2P file sharing, and use cases that have already leveraged the power and convenience of WebRTC.
Jan. 16, 2017 08:30 AM EST Reads: 3,051
WebRTC sits at the intersection between VoIP and the Web. As such, it poses some interesting challenges for those developing services on top of it, but also for those who need to test and monitor these services. In his session at WebRTC Summit, Tsahi Levent-Levi, co-founder of testRTC, reviewed the various challenges posed by WebRTC when it comes to testing and monitoring and on ways to overcome them.
Jan. 16, 2017 06:30 AM EST Reads: 5,872
"A lot of times people will come to us and have a very diverse set of requirements or very customized need and we'll help them to implement it in a fashion that you can't just buy off of the shelf," explained Nick Rose, CTO of Enzu, in this SYS-CON.tv interview at 18th Cloud Expo, held June 7-9, 2016, at the Javits Center in New York City, NY.
Jan. 16, 2017 06:30 AM EST Reads: 4,528
Every successful software product evolves from an idea to an enterprise system. Notably, the same way is passed by the product owner's company. In his session at 20th Cloud Expo, Oleg Lola, CEO of MobiDev, will provide a generalized overview of the evolution of a software product, the product owner, the needs that arise at various stages of this process, and the value brought by a software development partner to the product owner as a response to these needs.
Jan. 16, 2017 05:30 AM EST Reads: 1,110
WebRTC services have already permeated corporate communications in the form of videoconferencing solutions. However, WebRTC has the potential of going beyond and catalyzing a new class of services providing more than calls with capabilities such as mass-scale real-time media broadcasting, enriched and augmented video, person-to-machine and machine-to-machine communications. In his session at @ThingsExpo, Luis Lopez, CEO of Kurento, introduced the technologies required for implementing these idea...
Jan. 16, 2017 04:30 AM EST Reads: 4,549