Plugin dont use the FILTER to the layer

[aperi2007]

The new one plugin seem don't detect (or detect but don't use) the opzionally FILTER setting at layer level.

The exported mapfile don't show any filter setting.

I'll try to patch in my fork.

[aperi2007]

I see in the plugin code, the FILTER is supported only for the POSTGRES dataprovider,
my test are all using the spatialite. The spatialite qgis dataprovider allow a filter like the postgres, but the plugin code ignore it.

[aperi2007]

Resolved.
The solution is more simply rather than I guess.
The postgres code in the plugin was a good sample of what need to do.
:)

In the file "MapfileExporter.py" around the line 353 change this block of code:

-------
        elif layer.providerType() == 'spatialite':
            msLayer.setConnectionType(mapscript.MS_OGR, '')
            uri = QgsDataSourceURI(layer.source())
            msLayer.connection = toUTF8(uri.database())
            msLayer.data = toUTF8(uri.table())
-------

with this other block of code:

------
        elif layer.providerType() == 'spatialite':
            msLayer.setConnectionType(mapscript.MS_OGR, '')
            uri = QgsDataSourceURI(layer.source())
            msLayer.connection = toUTF8(uri.database())
            
            if uri.sql() != '':
                tempString = 'NATIVE_FILTER=(%s)' % str(uri.sql())
                msLayer.addProcessing( tempString )
            
            msLayer.data = toUTF8(uri.table())
------

The new code for the FILTER in a spatialite provider use a new sintax added to mapserver in the last released version.

Unfortunatelly I was not able to produce a PULL for github.
My customized version of the plugin has too many changes in it, and I'm not sufficient skilled on github to manage all this differences.