[Qgis-developer] Is it possible to re-use print composer code to build a web service ?

[Martin Dobias]

Hi Alessandro

On Mon, Dec 20, 2010 at 2:47 PM, Alessandro Pasotti <apasotti at gmail.com> wrote:
> Hi,
> I've spent a few hours exploring the codebase while I was thinking about
> building a web service to generate (vectorial) PDF for a map.
> IMHO this would be a must, expecially now that QGIS has entered in the web
> service arena with qgis-mapserver.
> The idea is to build a qgis-mapserver companion which would take care of
> building a PDF representation of the map using the configured project(s) and
> a print template.
> The idea is that the user can configure the WMS and print template from QGIS
> GUI, and have a  WMS + PDF-print service running with a few clicks.
> The obvious road for such a service is qgis-mapserver (read layers, map
> extent etc. from request like WMS does), + qgis-print-composer (read the
> template name, the resolutions and paper format from request) but it seems
> like the print-composer cannot work without a GUI, is this correct ?

Marco has refactored the composer code few releases ago, so now it's
possible to use the print composer by calling only qgis_core code.
There is also a simple example how to use the composer:

http://www.qgis.org/pyqgis-cookbook/composer.html#output-using-map-composer

The code saves only a raster image, though saving a PDF should require
only minor modifications of that code. If you will have any problems
adapting it, I'll try to provide also PDF example.

Regards
Martin