(content goes here) blog

Propose your blog for contentcentric.org

dev@day.com (Lars Trieloff) — 07 Oct 2008 00:00:01 GMT

Calling all bloggers that cover content-centric applications or content-related topics: if you would like to get added to the blog aggregation contentcentric.org(*) please drop me a line at ltrieloff(at)day(dot)com. I would love to hear from you.

(*) contentcentric.org is an aggregation of blogs of the content centric community. This includes Java Content Repository, Sling, and content centric applications like Content Management Systems, Blogs, Wikis.

Day's 2008 Global Customer Summit

dev@day.com (Ulrike Fox) — 07 Oct 2008 00:00:01 GMT

If you have not signed up to attend Day's 2008 Global Customer Summit…it is not too late!

Be part of the worldwide launch of Day's CQ5, at the 2008 Day Global Customer Summit, October 22-24, 2008 in Basel, Switzerland. Hear case study presentations from leading companies such as Audi, McDonald's, City of Zurich and University of Phoenix, among others.

Attendees will also have the opportunity to interact with senior Day executives, and hear a feature presentation from respected industry analyst Mick MacComascaigh from Gartner. David Nuescheler, Day CTO, specification lead and founder of the JCR standard, will launch Day's CQ5, and CEO Erik Hansen will deliver the keynote address.

To reserve your place at the summit, please email the completed registration form to summit@day.com, or fax to +41 61 226 9897 (invitation PDF and registration form in Word format).

State-of-the-art architecture for web content management systems

dev@day.com (Michael Marth) — 02 Oct 2008 00:00:01 GMT

When you start to implement a large software package you are usually (or should be) driven by your own needs or what your customers ask for. That is, you are driven by features. On the other hand, when you decide to re-write a software package that has been in production for a while features are often less in focus. Instead, you would probably decide to do a re-write in order to get the architecture "right", i.e. to adapt the architecture to everything you learned so far. Of course, as a developer you always strive for a fitting architecture. But the difference between the first implementation and the re-write is that in the latter case you know all the features that need to be supported and you know what your users tend to do with the software.

Let's look at two examples of established products that are currently being re-written in the WCMS world:

Our own Communiqué 5 and
on a very different side of the technology spectrum (PHP) there is Typo3 5.0

At OpenExpo I could attend a talk by Typo3 5.0 lead developer Robert Lemke and found that T3 5.0 and CQ5 independendly came to the same conclusion how a modern web content management system's architecture should look like. As I blogged about previously it is a 3-layered stack:

The foundation is a Content Repository with APIs that allow access to the content in its raw form (untainted with business logic). The top layer is the content management system itself that should consist of nothing but business logic (like workflows and the user interface for editors). Inbetween the two is an infrastructure layer that provides basic plumbing for web applications like security, connection handling to the repository, script execution etc. One important aspect to qualify this part as a layer is that it also exposes its own API.

The CMS is only one possible application that can run on the infrastructure layer, i.e. custom applications do not run "on top" of the CMS, but "next to" it. This is enabled by the fact that the infrastructure layer is independent of the CMS.

In our case the name of this layer is Apache Sling, in T3's case it is Flow3.

I am convinced that this striking similarity is not a coincidence, but rather a confirmation that this kind of architecture constitutes the state of the art of WCMS architecture. Especially, as these two systems are situated in very different ends of the WCMS ecosystem. Moreover, I know that we as well as the T3 devs have spend a significant amount of time thinking about architecture and evaluating approaches (which is usually another difference to first time implementations where urgent requirements need to be satisfied immediately).

I should note that there are plenty of differences between Flow3 and Sling, for example Sling maps directly maps content and URLs (which I personally find utterly fitting for a content-centric framework) whereas in Flow3 URLs address controllers.

PS: in case you wonder: yes, that IS a JCR-compliant repository written in PHP in Flow3.

[LOTD] InfoQ architecture

dev@day.com (Michael Marth) — 02 Oct 2008 00:00:01 GMT

Alexandru Popescu discusses the InfoQ.com site architecture which features a home-made Jackrabbit-based CMS. The persistence is split between JCR and Hibernate/RDBMS:

And then it goes down to the persistence layer which as I said is split between Hibernate and the JCR. So at the end we have two different storages. You can probably ask at this moment why we picked using two solutions for storing something that might have lived in the same storage. The problem was that when designing this application we weren't sure how the model will look and how our content will evolve over time, and dealing with these changes inside the relational schema is pretty difficult, complex to migrate data and maintain between different versions and things like that. The JCR API provides exactly this support for unstructured content and a couple of more features like versioning, full-text indexing and we are taking advantage of all of these features.

Sounds like Data First in action to me.

JCR is for more than just web content management

dev@day.com (Michael Marth) — 01 Oct 2008 00:00:01 GMT

There is an aspect in the adoption of JCR that is well-known, but not made explicit very often: While JCR is sometimes perceived as a technology for (web) content management systems the range of applications that are actually built on top of JCR is quite a bit broader. This is understandable as the feature set defined in JCR is useful for many use cases (like object-level security, versioning, hierarchical data structure, etc).

Recently, I stumbled across Boni Gopalan's blog which reminded me of exactly this fact. Boni's company BioImagene sells a software package for analysis and management of pathology images. He provides some reasons why they chose to base their software on top of JCR:

1. Pluggable security model that can maintain ACL at object level
2. Versionability for objects
3. ability to choose the right storage device for binary content Vs. ascii data.
4. Efficient pluggable search integration.
5. ability to integrate with JEE environments and lightweight spring like frameworks.
6. Import export support to and from XML.
7. Efficient transaction management and the ability to seamlessly take part in JTA.

This inspired me to compile an incomplete list of examples of some real-world applications that are built on top of JCR (which are not content management systems, document management systems, knowledge management systems, blogs or wikis) - more to be found in the Jackrabbit Wiki:

JBoss DNA which is a solution to:

Manage numerous types of software assets, artifacts, and components
Automated extraction of structured information
Visualize and understand the relationships between components

as well as JBoss Drools.
SOA governance platform Mule which

includes versioning, lifecycle management, dependency management and policy enforcement features which enable you to effectively govern your applications and services
The Zephyr test management tool uses JCR for managing test cases
Artifactory is a Maven 2 enterprise repository based on JCR
JCR is also used to store emails, see e.g. Jukka Zitting's extension of the James email server or our own discussion groups

This list illustrates why I regard JCR as a "horizontal infrastructure technology", not just as a "web content management vertical".

Day JCR Cup 08 - Last Chance to Enter!

dev@day.com (Greg Klebus) — 30 Sep 2008 00:00:01 GMT

Time flies incredibly fast, and here we are at the last day of Day JCR Cup 08 submissions. There are still a few hours to send your submission (the deadline is today, 30 September 2008, at midnight Pacific Time), so please don't forget to send your Sling application before that.

If you happen to have heard about it only today, don't despair - with mere 15 minutes to create your first application you still have enough time to create something nice, and even have a couple of cups of coffee in between! Seriously though, if someone would be up to such a challenge, please let us know in the submission that you just started today.

Fingers crossed for your submissions.

Your Day JCR Cup 08 Team

Day wins CH Open Source Award 2008 in the business category

dev@day.com (Michael Marth) — 26 Sep 2008 00:00:01 GMT

Day has won the Swiss Open Source Award in the business category. The members of the jury explicitly mentioned our involvement in Apache Jackrabbit and Sling, especially the activity of Day's developers on the respective mailing lists. The winners of all categories received a golden keyboard. See here for more information about Day's open source activities.

Two happy bald guys from Day, a juror and a golden keyboard (from right to left: Day's senior developer Bertrand Delacretaz, jury member Christian Stocker and me)

Quote of the day

dev@day.com (Michael Marth) — 26 Sep 2008 00:00:01 GMT

As an old Rails fanboy I cannot resist to quote Renaud Richardet:

Sling is the coolest thing since I tried Ruby on Rails

OpenExpo, blog example and JCR/OSGi installer

dev@day.com (Michael Marth) — 26 Sep 2008 00:00:01 GMT

Yesterday, Bertrand and I presented Sling at the OpenExpo in Winterthur. Although we had only 30 minutes for the whole presentation and started out from "what is JCR" we managed to do some live coding on stage. The example we had chosen was (again) a little blog, this time with some additional OSGi bundles though. The bundles could be installed by simply putting them in the JCR/WebDAV directory /apps/myblog/install. This is fabulous, because that allows Sling users to distribute one application as a content bundle (and not have to deal with separate packages that contain the OSGi bundles).

The example code is attached to a Sling Jira issue. I would like to get it commited as a Sling sample, but there is still some work to be done on it. In the mean time you can still get the code at Sling issue 673.

The presentation slides are here:

| View | Upload your own

Updating CRX Quickstart [Updated]

dev@day.com (Michael Marth) — 17 Sep 2008 00:00:01 GMT

There have been some bug fixes in Apache Sling since the last version of CRX Quickstart was released. In case you want to update CRX Quickstart with latest and greatest from Sling's svn here is a little how-to:

You need to have Maven installed.
Check out Sling from http://svn.apache.org/repos/asf/incubator/sling/trunk
cd into launchpad/testing and execute "mvn install" (to skip the tests execute "mvn -Dmaven.test.skip=true install" instead). If the build does not fail (which it could, this is the latest in trunk) there should be a new file org.apache.sling.launchpad.testing-4-incubator-SNAPSHOT.war (or similar) in launchpad/testing/target. This is your new war file.
If you run out of memory while compiling increase Maven's memory setting by setting the environment variable MAVEN_OPTS="-Xmx256M"
cd into jcr/jackrabbit-client and execute "mvn install" again. This will create a new bundle in jcr/jackrabbit-client/target.

When you ran CRX Quickstart it created a folder named crx-quickstart. You need to modify some files in this folder.

Make a backup of the crx-quickstart folder. If you need to keep your content also do an export (see http://localhost:7402/crx)
Delete crx-quickstart/launchpad
Replace crx-quickstart/server/webapps/crx-launchpad.war with the .war file created above (i.e. copy and rename the file to crx-launchpad.war).
Start CRX-QS and navigate your browser to http://localhost:7402/system/console/list (Sling's OSGi console). Uninstall the "Sling - Jackrabbit Embedded Repository" bundle. Install the bundle you created above.
Stop CRX and delete crx-quickstart/repository

That's all folks. This is all at your own risk and YMMV, of course.

Update (18/9/08): I missed some steps, unfortunately. Updated the post, thanks to Bertrand for pointing this out.