We advance one of the (many) novelties that the next gvSIG Desktop version includes and we think that it will be very useful. This new feature is the virtual fields support (also known as calculated or generated fields).
This fields contain values that are calculated when executing a certain formula that the user has defined. And, therefore, their values are automatically updated each time there is a change that affects that formula.
For example, in the next video, we can see how a virtual field with population density based on the values of two other fields (area and population) can be calculated. When changing any of those two values - in the video we can see how the population value is modified – we see how the density is calculated automatically again and it shows the new values.
Another example where the usefulness of these fields is shown is when we create a virtual field that calculates the area of the geometries. Each time we modify a geometry graphically… the polygon area will be updated.
In addition, with the new and powerful formula generator that has been implemented in gvSIG Desktop 2.5 (and which we will discuss in the next post), the possibilities are practically unlimited.