Archive for the ‘RIA’ category

GeoMondrian Example

November 18th, 2009

As soon as I’ve started digging into OLAP Architectures I realized how complicated things might become whenever looking for extra features. Most of the commercial OLAP solutions are providing “classic” OLAP features for data warehousing. It means that only simple numeric, strings and dates would be supported. Spatial Data Warehouses  architectures instead, are still in their infancy and there exists no commercial product that is actually providing such SOLAP functionalities. There exists several academic proposals instead which can provide a good overview on the features that can be supported by SOLAP Servers.

One of these acedemic prototypes is Geo Mondrian.

GeoMondrian is a spatially-enabled version of Pentaho Analysis Services (Mondrian). It has been released under the EPL. GeoMondrian is the first implementation of a true SOLAP server. It provides a consistent integration of spatial objects into the OLAP data cube structure, instead of fetching them from a separate spatial database, web service or GIS file. To make a simple analogy, GeoMondrian brings to the Mondrian OLAP server what PostGIS brings to the PostgreSQL database management system.

Unfortunately the documentation and getting-started guides are missing right now… That’s why I’ve decided to publish a couple of advices to whom may decide to use GeoMondrian for  developing SOLAP applications. Here attached you can find an archive that contains all that you need to setup a sample SOLAP server with geographic data source. It is designed to be working on PostgreSQL+Postigs since it is the only spatial database to be supported right now.

What you have to do in order to be able to use this unofficial build release of GeoMondrian is to load the .SQL script into your postgresql+postgis database and than run the Test application (be sure that the .XML schema definition is in the same parent directory, to have set up properly your JDBC connection and have included the libraries that are present in the “lib” folder).

I hope that it will help!

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All roads lead to Flash

May 3rd, 2009

 

 

Flash

When approaching a new design of a rich content web application, the same questions always come out: which is the best framework for the purpose?

Well.. depending on your definition of “rich” and also to the complexity of the interactions within the platform that you want to built up, a few approaches exist to solve this problem. The first possible I will call it the “Javascript” approach. Thanks to the affirmed level of the Javascript technology, there are a lot of interesting libraries (such as JQuery or Dojo) that can provide the developer of a powerful toolkit for building fancy interactions and ready to go components. Especially if paired up with other strong Ajax frameworks (like Zend Framework), it can create a spicy mixture that boosts the development process. But what about the “after”? Usually independent programmers  don’t care that much about the maintenance of the code… and more generally about the application development process, since the majority of software project failures are registered in the development phase.

But what if the project results successful? Code maintenance could be as much harmful as software development! In such situation I would personally have preferred to have chosen the second approach, that I will call “the Flash approach”. Nowadays flash players are installed in every PC, and a web browser without flash player support… has more than a half of the websites unavailable for its users. Flash movies are embedded everywhere (for Video streaming, Audio streaming, Slideshows…) but the power of flash movies is not only on the easy interface and interfacing power (i.e. a .swf movie can be considered as a small, fast web  embedded application). A lot of programming languages have moved forward to match that standard and provide different languages to create complex flash compiled web applications . Those ones built in flash are not only fast to develop, but also to maintain. Opposing to their javascript competitors, websites built in flash (e.g. the famous French music website Deezer) take both positive aspects from website applications and standalone ones. Hence  from a developer point of view, those websites are nothing more than a set of compiled applications, merged together in a light fashion to be served by the Internet community.

Just to have a taste of what is outside for the Flash development,  I listed some swf generators APIs:

  • Flex: obviously the mastered languages from Adobe to create flash applications, it provides an XML based language as support to the Actionscript interactions
  • OpenLaszlo: a direct competitor of Flex. It provides a similar XML based syntax to build .swf web applications
  • Ming: a C , C++, PHP, Python, Ruby, and Perl (yes you have understood…) library to generate SWF files