I am trying to set the edit type of a vector layer to use a value relation. The Python commands below are processed without errors or warnings, but the when I check the properties in QGIS, only the EditType is set, but the data settings are empty. I use:

vlayer.setEditType(12, QgsVectorLayer.ValueRelation)
vlayer.ValueRelationData( 'releatedtable20131027113855772', 'key', 'value',False, True)

I got the name of the related table by inspecting:

ml=QgsMapLayerRegistry.instance().mapLayers()
dict(ml)

My guess is that I use the wrong string for referencing the layername. I have two questions: How to get the layername string to be used in ValueRelationData? Should I add further code to get it all working?

Thanks, Harm Olthof