Re: relevant and required

In a message dated 29/10/01 11:03:46 GMT Standard Time, josef@mozquito.com 
writes:


> As a reply to Andrew's remark: it is well possible that non-relevant
> form fields are hidden, but it is not the only way to represent that.
> Another representation is to essentially gray out the option and make it
> inaccessible. In that case, it is still "there", but it is not active.
> One advantage or greying the control out is that the arrangement of the
> widgets on the page is not significantly changed when the widget in
> question becomes relevant, whereas hiding it would require a
> re-shuffling of screen real estate.
> 
> Of course all this applies to visual rendering only, and for example a
> future voice interface may have to behave differently. That is the
> reason why the spec says: "The XForms User Interface _MAY_ indicate that
> should the form control become relevant, a value would be required."
> (emphasis mine)
> 
> Again: Does this help?

Josef,

Thanks for the reply and the reminder that form controls may be unavailable 
as well as hidden. I shouldn't have rushed my reply.

I am still struggling with the idea of when I might want to know if something 
that is not (currently) relevant would be required IF it was relevant. If the 
item is irrelevant then I can't immediately see why I would want to know that.

Suppose, I had account with an e-business that allowed payment on account or 
by credit card. If I selected to pay on account then why would it be of 
interest to me whether or not a credit card number might be required IF I had 
made a different choice?

An example of where it would be of practical use to know that would be 
helpful for me to understand.

Is it possible that, perhaps in a desire for completeness, that more of the 
underlying model is being made (optionally) visible to the user in a context 
where it is unlikely to be of relevance to the user?

Rodrigue's question raises additional points which I admit to not having 
thought through yet. What happens to the display of captions / hints for form 
controls that are not relevant and are greyed out? [If it's in the WD forgive 
me but it didn't "stick" when I last read through it.]

Regards

Andrew Watt