Keywords: webmapping, thematic cartography, chart, business mapping, SVG, ECMA Script, XML
Georg Held holds a degree in Cartography/Geomatics from the University of Applied Sciences Karlsruhe, Germany. Apart from his studies, he was involved in several cartographic and GIS projects in both Germany and New Zealand. His last contractor was IVU Traffic Technologies AG Berlin, Germany, were he did research work in the field of SVG in context with webmapping. Several projects, e.g. the real-time presentation of the German parliament elections 2002 were focusing on webmapping and webgraphics with SVG. He wrote his final thesis on a SVG Viewer presenting thematic webmaps for business purposes like Business Intelligence. This work was done in cooperation with his last employer in 2002/2003.
The geographic visualisation of business data offers new perspectives for decision-makers. Such illustrations prove to be a good base for leading a company efficiently. In order to create business maps, geodata are combined with economic, social and demographic information in complex ways. To visualise a company's performance, sound knowledge of the thematic cartography domain and its methods are required.
The lack of web-based applications to achieve such an intricate "map production" was the main motivation, to examine whether SVG and its neighbour technologies are suitable at the current stage. It is well known that these technologies have the ability to do so, in theory. But present implementations need to be proven in a practical way. I was in charge of a research project by IVU Traffic Technologies AG Berlin, Germany last year.
This presentation shows a SVG map viewer solution to present business data within high quality interactive thematic maps. The main focus of the project was the client-side generation of such illustrations. In order to guarantee simple system integration, the data source is split into three components: geodata, thematic information and mapping properties
All sources of information are defined in well-formed XML configuration files, which are served and transferred to the client (currently: Win + IE6 + ASV3). In order to integrate these data, complex ECMA/Java scripting is necessary. Programming concepts, like object orientated programming, are the key to develop such cutting edge applications. Additional XML information is loaded by the methods of one specific object using getURL() and parseXML().
Geodata are predefined in valid SVG Elements which are appended to the SVGDom. In order to provide thematic information to the chart factory, an ECMA Script object for DataSet's is instantiated. The chart factory itself is represented by another object. Its methods are responsible for the creation of the SVG Charts. The current implementation offers methods for the creation of many types of point-based charts, like pies or bars, line-based charts and choroplethe maps.
The mapping properties represent various additional information about design and styling. Two major kinds of properties are differentiated. First, global properties, which describe default settings in order to append a new GUI-Design and change the initial view. Second, map layer specific values which handle chart properties like the maximum size of a circle chart. Because of the global properties, the viewer is fully configurable. Furthermore, spatial navigation like zooming and panning is implemented. In case of business maps, drill-down and roll-up mapping is demanded. To achieve a drill-down, all data and properties of the next map layer are requested by the client. Data, which once has been loaded, is cached within the viewer. In this case no further client-server interaction is needed. Additionally, map components like overview, legend and map scale are created and controlled by instances of specific ECMA Script objects and their methods. In order to apply styles to the viewer, a global Cascading Style Sheet document is defined.
The resulting application is a state of the art solution which is usable as a base for real world mapping purposes. The contemporary programming concept allows easy integration of new map types, e.g. additional chart types. The project's results show that SVG and neighbour technologies are very well suitable for practical use. The viewer will be included as a web component for business intelligence systems.
At the end of the presentation, risen issues like the complicated way of integrating a global navigation concept in this standalone SVG application will be discussed.
What are business webmaps
Requests on such a map viewer
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