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Re: Implementors please read: poll about select1 and empty values

From: Erik Bruchez <ebruchez@orbeon.com>
Date: Tue, 21 Dec 2010 19:06:04 -0800
Message-ID: <AANLkTimzHgptqDMG12kvGEM5sRMUaCSF9zJgoJ7ufaQJ@mail.gmail.com>
To: Forms WG <public-forms@w3.org>, www-forms@w3.org
Got it.

Our implementation does an exact match, whether the value is empty or not.

It seems a bit odd to me to make empty value behave differently from any
other value, and I could bet that the default expectation for a form author
would be to assume that, if an empty value is legal for an itemset value,
then it should match an empty value in instance data.

-Erik

On Wed, Dec 15, 2010 at 9:43 AM, John Boyer <boyerj@ca.ibm.com> wrote:

>
> Hi Erik,
>
> Quick notes:
>
> 1) The poll is not about the question you answered in this email.  I think
> we pretty much answered the original question with the "exact string match"
> behavior that you use everywhere except on initial load, so adjusting your
> initial load to be a string match without trimming would be best considering
> the answer we sent out already.
>
> 2) The poll question is asking what happens to a select1 when the ref of
> the select1 binds to a node with empty content and the select1 contains an
> item whose value is empty.  To make it easy, say you use appearance="full"
> so that you get a radio button group.  Let the item with the empty value be
> the middle of three item elements in the select1.  Does the radio group show
> no items selected or does it show the middle item as selected?
>
> Cheers,
> John M. Boyer, Ph.D.
> Distinguished Engineer, IBM Forms and Smarter Web Applications
> IBM Canada Software Lab, Victoria
> E-Mail: boyerj@ca.ibm.com
>
> Blog: http://www.ibm.com/developerworks/blogs/page/JohnBoyer
> Blog RSS feed:
> http://www.ibm.com/developerworks/blogs/rss/JohnBoyer?flavor=rssdw
>
>
>
>
>  From: Erik Bruchez <ebruchez@orbeon.com> To: www-forms@w3.org, Forms WG <
> public-forms@w3.org> Date: 12/14/2010 11:20 PM Subject: Re: Implementors
> please read: poll about select1 and empty values
> ------------------------------
>
>
>
> All,
>
> I haven't yet had time to fully dig into this, but our implementation
> seems to trim strings on both sides before comparison, but only on
> initial show of the page to indicatedthe initially-selected item. That
> would be a bug!
>
> Other than that, the Orbeon behavior is to do an exact string match
> with select1 (as pointed out, it doesn't for select).
>
> (BTW Leigh, I can't seem to run your test case page right now.)
>
> -Erik
>
> On Wed, Dec 8, 2010 at 10:09 AM, Leigh L. Klotz, Jr.
> <Leigh.Klotz@xerox.com> wrote:
> > A question has come up about conformance and interoperability of XForms
> > processors with regard to the behavior of select1 when a value is the
> empty
> > string or whitespace only.
> >
> > This message is a poll to find out how select1 with an empty item/value
> > element behaves in existing XForms 1.1 implementations.  Based on the
> > results of this poll we may add additional test cases, additional
> > clarification, issue an erratum, or propose new features for XForms 1.2.
> >
> > Background:
> > The XForms 1.1 Recommendation says [1] about select1 (and select as
> well):
> >
> >
> > "For both closed and open selections, any selection item with a storage
> > value which is empty or which contains only white space characters must
> > remain deselected."
> >
> > Discussion:
> > Nick van den Bleeken tentatively reported that least one implementation
> > supports a select1/item/label for the empty item/value.
> >
> > John Boyer and I both noted that select has this implementation
> requirement
> > because its space-separated values in list content are indistinguishable
> > from empty.  In short, the absence of any selected item is ithe
> indication
> > that no item is selected.
> >
> > John further noted, however, that the requirement on select1 is motivated
> > not only by consistency with select, but also by another point, that the
> > "required" MIP be used to indicate that a value has been set.  John noted
> > that xsi:nil can also be used for this purpose, but is not well
> understood
> > or implemented.
> >
> > John suggested to form designers that a "none" value for any select1
> > control-bound data would better be represented by a distinguished value
> > chosen by the application, e.g. "none" or "n", rather than an empty
> value.
> >
> > I noted that only if the XForms application and the data are co-designed
> can
> > the form designer can satisfy this requirement, and that web resources
> may
> > require an empty string to indicate a value of "none," and that allowing
> a
> > binding of a label gives form designers the ability to express this UI.
> >
> > As a result of this discussion, we are polling implementations and
> seeking
> > feedback on the presentation and behavior of empty ref node values and
> empty
> > item/value (and by extension, itemset) in select1.
> >
> > Test Case:
> >
> > I have produced a test and made it work using xsltforms.
> > It is available at http://xformstest.org/2010/12/select1-empty and
> please
> > choose select1-empty.xml
> > We're asking implementors to adapt and run this test case and report
> > behavior.
> > A sample report is below:
> >
> > Test Case Results Example
> > For the sample I produced, here are the results for the select1 cases
> with
> > an empty item/value.
> > (The test page also includes controls with no empty item/value).
> >
> > no appearance:
> > displays as pulldown menu
> > empty value displays as a blank item inside select1. (to spec)
> > selecting the "(empty)" labeled item causes only that control to change.
> > (partially to spec)
> > after that, selecting the unlabeled item causes all form controls bound
> to
> > the node to change to the "(empty)" labeled item (not to spec)
> > selecting the "full" labeled item causes all controls to change to
> "full".
> > (to spec)
> > selecting the "full" labeled item causes the blank item to disappear from
> > all select1 controls, however the explicit "(empty)" choice remains.
> > selecting the "(enpty)" labeled item again causes the blank item to
> > re-appear in all select1 controls (???)
> >
> >
> > appearance=minimal:
> > displays as pulldown menu
> > same behavior as above
> >
> > appearance=compact
> > displays as in-place visible menus with one selection allowed
> > same behavior as above
> >
> > appearance="full"
> > displays as radio buttons; no blank or unlabeled radio button
> > empty value displays as a selected "(empty)" radio button. (NOT to spec)
> > selecting the "(empty)" labeled item causes all form controls to change
> to
> > display the unlabeled item. (to spec)
> > selecting the "full" labeled item causes all controls to change to
> "full".
> > (to spec)
> > selecting the "full" labeled item causes the blank item to disappear from
> > all select1 controls, however the explicit "(empty)" choice remains;
> > selecting the "(empty)" labeled item again causes the blank item to
> > re-appear in all select1 controls. (???)
> >
> > Of the above, only the full appearance (radio) had a notable behavior: it
> > offered no way to choose the empty item, and if the empty item were
> chosen
> > by another control, it displayed with no selection.
> >
> > Leigh.
> >
> >
> > [1] http://www.w3.org/TR/xforms11/#ui-selectOne
>
>
>
>
Received on Wednesday, 22 December 2010 03:06:54 UTC

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