How to mimic the 'mandatory' functionality

Question

When I set a field to mandatory, and subsequently hit 'Submit', the fields(s) are all highlighted at once, with 'Please complete the mandatory field before submitting'.
How can I replicate that in javascript since my criteria for mandatory is a little more complex?

Answer 1

Feel free to experiment and/or reverse engineer the addValidator code  (it's in a JavaScript library under RequestCenter.war) if you want to figure out what the parameters do. I think that addValidator was originally intended to be more robust, and to allow user-specified validation, but that functionality was never implemented. Therefore, the "null" and true are pretty much the only values that work in these parameters. 
As for building up a dynamic error  message, you could probably do that by clearing out existing validators (hmm, Tylor, didn't I once find you the code for that? something like serviceForm.dictionary.field.validators = '') and building the desired string via JavaScript. This functionality would need to be fired in an onChange event, however, or some time before the onSubmit event.  Typically, the addValidator is just done in an onLoad event to set up validation considered to be unchanging throughout the life of the service form.