Having this simple form. We can navigate to rules clicking on the marked button.
For each of the elements we have a number of properties or events that we can manage,
For example we can manage form load event, or get if a field value is valid...
Let's build a couple of rules so you can see how easy it is.
Having this combo with this value.
We can build a rules that populates that combo and also add some kind of value change listener so if its value is "Spain" we can set the country code in Telephone field.
If we have any syntax errors, will be displayed in the bottom of the editor.
Once the error is fixed we can test the form clicking on the marked button.
We can see that the combo is now populated and if we select Spain, the country code is set.