Re: Required but empty (PR#83)

Hi Erik,

The working group considered this issue and felt that the definition of empty
string as being zero characters (as opposed to zero non-whitespace characters)
was well-known enough not to need clarification and that this is the definition
that we should be using for the 'required' MIP as it is consistent with the
notion of empty string in XML schema and XPath.

We do agree that there are forms in which one might not want to distinguish
empty from containing only whitespace.  We believe this can be done via the
constraint MIP, though we agree with your statement in [1] that it is reasonable
to consider how this capability might be more simply accessed in a future
version of XForms.

[1] http://lists.w3.org/Archives/Public/public-forms/2007Jul/0078.html

Thank you,
John Boyer

> 
> All,
> 
> I have a doubt about the meaning of "empty" in the wording "required but
> empty" (which appears in 11.2.3 and 4.3.5).
> 
> It seems that "empty" could either mean:
> 
> 1. A zero-length string (clear technical interpretation)
> 2. A string empty as per #1 above, or a string with only white-space
>      (human-friendly interpretation)
> 
> Imagine a user entering by error a space in an input field. Visually,
> with most agents (typically web browsers), you can't tell whether the
> field is empty according to #1 above, or contains white space. So to the
> user, the field is "empty".
> 
> But if the XForms implementation implements #1, then this visually empty
> field will be considered non-empty, and pass submission even if required.
> 
> This would favor an interpretation of "empty" where not only strictly
> empty strings are "empty", but also strings containing only white space.
> 
> At the very least, the spec should say whether it means #1, #2, or
> implementation-dependent.
> 
> -Erik
> 
> -- 
> Orbeon Forms - Web Forms for the Enterprise Done the Right Way
> http://www.orbeon.com/
> 
>

Received on Thursday, 26 July 2007 18:38:01 UTC