I'm editing a lot of polygons of a shapefile in QGIS and I need to classify them, so I have to write the classes repeatedly. In ArcMap there is an option to have domains set for the fields.
How do I do this in QGIS?
You can customize the attribute editing to various data types (predefined lists, a range of values or a date).
Right-click > Properties
.Field
tab. Value Map
option will ask for your pre-defined classification values. When you start adding new polygons a drop down list should appear showing your list of classes. The below screenshot is from QGIS 1.7.
The nice thing of having widget type with value map is that it also works on existing features.
Just click on it with the i+arrow (identify feature or CTRL+SHIFT+I) to get the menu back with options to choose from.
I have virtual fields depending on the chosen item and it works like a charm.