Python - Unique Value Renderer

Hi All,

 

I’m trying to figure out how to setup a layer with a unique value renderer using the python bindings.  It seems like it should be straightforward, but I’m obviously missing something, because it doesn’t work.

 

This is what I’ve got so far:

 

        layer = QgCore.QgsVectorLayer(‘data/title.shp’,’Title Parcels’,’ogr’)

        layer.setScaleBasedVisibility(True)

        layer.setMinScale(minScale)

        layer.setMaxScale(maxScale)

        blackColor = QtGui.QColor(0,0,0,255)

        yellowColor = QtGui.QColor(255,255,190,255)

        greenColor = QtGui.QColor(174,241,176,255)

        orangeColor = QtGui.QColor(246,197,103,255)

        greyColor = QtGui.QColor(178,178,178,255)

        rnd = QgCore.QgsUniqueValueRenderer(QgCore.QGis.Polygon)

        prov = layer.getDataProvider()

        rnd.setClassificationField(prov.indexFromFieldName(‘Ownership’)

        sym0 = QgCore.QgsSymbol(QgCore.QGis.Polygon,"0","0","Unknown")

        sym0.setFillColor(greyColor)

        sym0.setColor(blackColor)

        sym1 = QgCore.QgsSymbol(QgCore.QGis.Polygon,"1","1","Private")

        sym1.setFillColor(yellowColor)

        sym1.setColor(blackColor)

        sym2 = QgCore.QgsSymbol(QgCore.QGis.Polygon,"2","2","County")

        sym2.setFillColor(orangeColor)

        sym2.setColor(blackColor)

        sym3 = QgCore.QgsSymbol(QgCore.QGis.Polygon,"3","3","Crown")

        sym3.setFillColor(greenColor)

        sym3.setColor(blackColor)

        rnd.insertValue("0",sym0)

        rnd.insertValue("1",sym1)

        rnd.insertValue("2",sym2)

        rnd.insertValue("3",sym3)

        layer.setRenderer(rnd)

 

The layer itself is a polygon shapefile with a field called “Ownership”.  The field is an integer field with four different values, 0 to 3.  When I run my application, the Title Parcels layer is rendered with a black outline and a white (or perhaps hollow) fill colour.

 

How do I make the unique value renderer work properly?

 

Thanks,

Rob McCulley

GIS Coordinator

County of Vermilion River

(780) 846-2244

www.vermilion-river.ab.ca

 

I’ve managed to solve it.  The problem was rather simple.  I was thinking it was a problem with the classification, when it was really a problem with the symbols.  All it took was to add a sym0.setFillStyle(QtCore.Qt.SolidPattern) to each of my symbols.

 

Rob

 

 

Hi All,

 

I’m trying to figure out how to setup a layer with a unique value renderer using the python bindings.  It seems like it should be straightforward, but I’m obviously missing something, because it doesn’t work.

 

This is what I’ve got so far:

 

        layer = QgCore.QgsVectorLayer(‘data/title.shp’,’Title Parcels’,’ogr’)

        layer.setScaleBasedVisibility(True)

        layer.setMinScale(minScale)

        layer.setMaxScale(maxScale)

        blackColor = QtGui.QColor(0,0,0,255)

        yellowColor = QtGui.QColor(255,255,190,255)

        greenColor = QtGui.QColor(174,241,176,255)

        orangeColor = QtGui.QColor(246,197,103,255)

        greyColor = QtGui.QColor(178,178,178,255)

        rnd = QgCore.QgsUniqueValueRenderer(QgCore.QGis.Polygon)

        prov = layer.getDataProvider()

        rnd.setClassificationField(prov.indexFromFieldName(‘Ownership’)

        sym0 = QgCore.QgsSymbol(QgCore.QGis.Polygon,"0","0","Unknown")

        sym0.setFillColor(greyColor)

        sym0.setColor(blackColor)

        sym1 = QgCore.QgsSymbol(QgCore.QGis.Polygon,"1","1","Private")

        sym1.setFillColor(yellowColor)

        sym1.setColor(blackColor)

        sym2 = QgCore.QgsSymbol(QgCore.QGis.Polygon,"2","2","County")

        sym2.setFillColor(orangeColor)

        sym2.setColor(blackColor)

        sym3 = QgCore.QgsSymbol(QgCore.QGis.Polygon,"3","3","Crown")

        sym3.setFillColor(greenColor)

        sym3.setColor(blackColor)

        rnd.insertValue("0",sym0)

        rnd.insertValue("1",sym1)

        rnd.insertValue("2",sym2)

        rnd.insertValue("3",sym3)

        layer.setRenderer(rnd)

 

The layer itself is a polygon shapefile with a field called “Ownership”.  The field is an integer field with four different values, 0 to 3.  When I run my application, the Title Parcels layer is rendered with a black outline and a white (or perhaps hollow) fill colour.

 

How do I make the unique value renderer work properly?

 

Thanks,

Rob McCulley

GIS Coordinator

County of Vermilion River

(780) 846-2244

www.vermilion-river.ab.ca