Trifork Blog

Posts by David Caron

Trifork implements Overstapservice Onderwijs (OSO)

December 4th, 2012 by

Trifork is currently busy implementing the Overstapservice Onderwijs (OSO) Traffic Center, a system that mediates the transfer of student files between schools. The Traffic Center standardizes the exchange of student files between primary- and secondary schools. The OSO project is a continuation of the Electronisch Leerling Dossier (ELD) project. It enables the digital transfer of student related documents between the individual student administration systems (LAS) of schools, regional initiatives and other stakeholders. A major challenge for the Traffic Center is that by law it is not allowed to store the student files, but it is purely facilitating the exchange.

In this blog entry I provide some insights into how the exchange is eventually facilitated and some of the challenges we had with it.

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Vaadin portlets with add-ons in Liferay

March 27th, 2012 by

The Vaadin web framework has been around for quite some time now, and for a couple of years it also supports portlet development. This is particularly the case for the Liferay portal, where some integration work has already been done for you. Using Vaadin to build Liferay portlets is rather nice, because until you actually become dependent on the Liferay API, your Vaadin project can still run stand-alone, giving you quick feedback during development without having to redeploy the portlet.

Working with Liferay is, like most things in Vaadin, well documented in the “Book of Vaadin”, in chapter 13, but there are some complications. As Vaadin uses GWT under the hood, an application needs a GWT widget set. If you just use standard Vaadin components, the widget set is prepackaged in the war file, but if you start using Vaadin add-ons or custom built components, you need to recompile the widget set. A limitation of running Vaadin portlets is that the widget set needs to be available centrally in the Liferay web application and is shared by all Vaadin portlets. This means that you’ll have to update this widget set in Liferay while your project grows.

The bits of information needed to put this all together are available on the web, but sadly scattered over reference manuals, wikis, blogs and forum posts. In this blog I’ll go through it incrementally. Probably you know most of the steps already, but then again, if you knew them all you wouldn’t be here 😉

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