I was working on a form the other day in one of my flex applications. The flex framework provides several different built in controls for doing validation. NumberValidator, StringValidator, ZipCodeValidator all of these classes extend the base Validator class. We create one instance of a validator class for each of the fields we want to validate and bind the source and property values of the validator to our input control.

No matter how you use your validator it all starts there. However from this point there are several paths you can take to test the validity of your inputs. For the examples I am going to show we are going to have a simple base application. Just two input fields we are going to validate. Such a sample application might look something like this.