Flex 3 in Action

Chapter 6. Validating user input

This chapter covers: Validation versus enforcement Pass-through validation Committed-value validation Scripted and real-time validation

Conducting client-side validation is a key strength of Flex. From a usability point-of-view you want your application to do as much prevalidation as possible. This helps to avoid aggravating situations in which a user spends a fair amount of time filling out a large form then clicks the submit button, only to find something is wrong with the input.

This is exactly the sort of thing that prevents an application from being fluid. In the HTML environment you have JavaScript to handle some data validation. How many times have you filled out a form, only to find out the password you provided ...