QGIS » QGIS Application

I don't know SEXTANTE internals. My idea was, that each algorithm/module would offer list of supported input and output formats with preference weight. All GRASS raster modules, for example, would offer 'GRASS native' with high preference and all GDAL formats with lower preference. SEXTANTE or maybe the modules (?) would choose the best offered output format from previous module in pipe. Two consecutive GRASS commands would use GRASS native, for example.

I have looked briefly into SEXTANTE Programming Guide 1.0 and to the plugin 1.0.5 code. The guide states that GeoAlgorithm reads/writes data via classes which extend AbstractRasterLayer/AbstractVectorLayer (implementing IRasterLayer and IVectorLayer). The GrassAlgorithm however seems to take tif/shp file names as input instead. What is really the input/output interface of a GeoAlgorithm?

Radim

That is how the Java version works. SEXTANTE for QGIS is different from that. SEXTANTE for QGIS uses a different approach and cannot be run in different GIS, just in QGIS. Its architecture makes it easier to reuse external apps, such as GRASS. Basically, all layer passing is done through filenames. In case the algorithm is an external one, it will open the given file itself (The GRASS algorithm first import the layer into GRASS, then lets GRASS do the processing and then exports the result to a format that QGIS can read). If it is an algorithm directly coded in Python into QGIS, it will use the layer from the QGIS list of layers, finding the one corresponding to that filename.