I would like to introduce the project “Using the ILWIS framework for geo-data capture with a mobile application”. This is one of the Google Summer of Code projects hosted by 52°North.
The project is mentored by ITC since they are the developers of ILWIS-Objects. ILWIS-Objects is the next generation ILWIS, which is a GIS environment. The idea behind it is that it won’t be ‘just’ a desktop GIS application, but a framework for many different scenarios, applications and platforms.
The core of each GIS is of course built around the spatial data (duh). So how we access that data (on a programming level) should be of prime importance when designing Ilwis-Objects. Some people would argue that the organization of data is of prime importance but I don’t agree with that. Organization should be a technical derivative of how I want to access my data. I don’t care if there is a database behind my interfaces or a file based system or a service or…. I just want to do things with my data. Organization is important, but only insofar it serves the interfaces.
So what do I require of my interfaces?
Last week I talked a bit about what connectors are supposed to do. As mentioned there, their main task was to translate external representations to internal ones. This week I want to focus a bit on the internal representation. After all, that is what people will use when programming with ILWIS-Objects.
The design of the internal representation leans heavily in some ways on the existing implementation; in other ways, it deviates sharply from that. It was/is maybe somewhat surprising that an 18 year old design is still very relevant these days. At a high level, the data structure has not changed that much. We still talk about data layers and coordinate systems, the problem of the data’s semantics still has to be addressed and tables are still tables. What has changed is the nature of the data itself. Where 2D data was sufficient in the past, we now talk about 3D, 4D and even 5D data. We see the size and availability of data sets explode and we see the complexity of relations between data sharply increasing. So the claim is, while the nature of data certainly has changed, the overall structure has not changed as much.
Last week I wrote about the high level design and structure of the next generation of Ilwis. This week I will focus on one of the most important parts of it, the connectors. In the picture of last week (part of it below), they made up the whole lower part of the second diagram
