This abstract wants to introduce an extended WMS server based on the QGIS
libraries. QGIS is a user-friendly desktop GIS, which supports various vector,
raster, and database formats. The new QGIS WMS server executable is a CGI
application that uses the QGIS functions without opening any GUI. It not only tries
to implement the OGC WMS and SLD standards – so that it will work with any generic
WMS client – but it implements also new features.
One of these new features is the usage of SLD for the configuration/administration
of layers and styles. An “admin.sld” file, having XML-based syntax, is used for the
server configuration. The standard SLD elements are extended with new tags which
describe the data sources and their type.
QGIS WMS is also trying to implement a basic user authorization by accepting
optionally two parameters (user and password) over an encrypted connection (HTTPS).
Based on the user authorization and by providing the possibility of
uploading/removing layers and styles, the software administration costs and
deployment efforts will also be reduced.
Alongside the standard HTTP “GET” and “POST” bindings, also a SOAP binding is
envisioned. The SOAP binding along with the service description in WSDL will
support automatic client generation. Additionally, this approach will allow the
clients to send their data (in GML) as part of the request message. As cartographic
enhancements of the WMS/SLD standards, new symbolization possibilities like
diagrams for thematic web maps are introduced.
Beside the presentation of these new features, the talk will illustrate - from a
technical point of view - the process of transforming an existing desktop GIS like
QGIS into a functional WMS server. |