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RE: xforms:copy binding query

From: Robert Walpole <robert.walpole@devon.gov.uk>
Date: Tue, 23 Oct 2007 21:59:01 +0100
Message-ID: <C9EA440929C8264DAB7C215BD4B2D65C04C5FB0D@dschl72.ds.devon.gov.uk>
To: "John Boyer" <boyerj@ca.ibm.com>
Cc: "Aaron Reed" <aaronr@us.ibm.com>, <www-forms@w3.org>, <www-forms-request@w3.org>
Hi John, 

Thanks for your reply. To avoid any further confusion I will stick to the real world example of what I am trying to do. 

Basically, I have a target XML node which is a <metadata/> element. On my form I want to have 2 select controls. One with accessibility options and one with clientgroup options. Each of these controls is populated with a different itemset. When the user selects options from the controls I want the selected items to be placed in the same metadata target node.

In other words, if the user selects 2 options from the accessibiliy list and 2 options from the clientgroup list I want the resulting XML to look like something like this.

<metadata> 
        <accessibility>1</accessibility> 
        <accessibility>2</accessibility> 
        <clientgroup>a</clientgroup> 
        <clientgroup>b</clientgroup> 
</metadata> 

Previously I have attempted to handle this using xforms:select1 within an xforms:repeat and an associated trigger to add additional form controls and therefore multiple elements of the same name. However the more complex the data model the more cumbersome this becomes and so I am trying to use xforms:copy as a more elegant solution. The problem I am having with this is that the bindings to the target node appear to be mutually exclusive and in the implementation I am using (Chiba) I am physically unable to select items from both lists. I can select multiple items in one list and then as soon as I start selecting items in the second list the items in the first list are deselected and do not show in the submitted data.

I am not sure what you mean by an "out of range event". I assume that this is something handled by the implementation? In any event a colleague of mine has added the xforms:copy functionality to Chiba so it is possible we may be able to modify the behaviour, if appropriate.

It may be that the only answer is to change my model so that each select control has a different target node. The problem with this is that I am working with a existing dataset and this kind of restructuring is not desirable.

Thanks again.
Rob Walpole 
Devon Portal Developer 
Email robert.walpole@devon.gov.uk 
Web http://www.devonline.gov.uk 


-----Original Message----- 
From: John Boyer [mailto:boyerj@ca.ibm.com] 
Sent: 23 October 2007 15:31 
To: Robert Walpole 
Cc: Aaron Reed; www-forms@w3.org; www-forms-request@w3.org 
Subject: RE: xforms:copy binding query 



Hi Robert, 

It's not clear enough from your first message what you are actually trying to do. This latest post involving use of insert surely seems to be going in the wrong direction, though, as the point of copy is that you don't need generalized insertion capabilities. 

I understood that you wanted two different controls to be able to contribute to a test data result. 

OK, so that means the ref of the two controls points at the same node "/test/data" 

But what is the itemset nodeset supposed to point at in the two different controls? 

Are you thinking to have the two itemsets be different? 

If so, I think it is only slightly problematic.  However, it should be possible to make it work, and in particular to do so without use of insert, but there will be a minor hiccup in the fact that each of the select controls will receive out of range error events for the subtrees placed in "/test/data" that do not correspond to items in the union of the item sets but not the complement of their intersection. 

In other words, if you have an item generated by control S1 but not S2, and you select that item, the subtree will be copied into the node referenced by S1, but S2 should then receive an out of range event because it has no item to match that copied node.  But this is a notification event, which could be ignored or cancelled. 

Finally, perhaps let us know what you really want to do at a higher level, since a solution other than having two selects with non-identical item sets might present itself.  But if it is exactly what you need, it should in principle work, modulo the out of range notifications. 

Cheers, 
John M. Boyer, Ph.D. 
STSM: Lotus Forms Architect and Researcher 
Chair, W3C Forms Working Group 
Workplace, Portal and Collaboration Software 
IBM Victoria Software Lab 
E-Mail: boyerj@ca.ibm.com  

Blog: http://www.ibm.com/developerworks/blogs/page/JohnBoyer 




"Robert Walpole" <robert.walpole@devon.gov.uk> 
Sent by: www-forms-request@w3.org 
10/23/2007 04:01 AM To"Aaron Reed" <aaronr@us.ibm.com>, <www-forms@w3.org> 
cc 
SubjectRE: xforms:copy binding query 







Hi Aaron, 

Thanks for your reply. I understand what you are saying about the 
bindings although this does seem a bit of a limitation. 

I am interested in your suggestion of using the xforms-select event but 
I am struggling to see how this would work. 

At present I am just trying to get it to work with one select control 
and I have something like the following: 

<xforms:model> 
                <xforms:instance> 
                                 <communitygroup> 
                                                  <data/> 
                            <metadata/> 
           </communitygroup> 
     </xforms:instance> 
                <xforms:bind id="data" nodeset="/communitygroup/data"/> 
     <xforms:bind id="metadata" nodeset="/communitygroup/metadata"/> 
     <xforms:instance id="accessibility-instance" 
src="accessibility.xml"/> 
</xforms:model> 

<xforms:select bind="data"> 
                <xforms:label>Metadata</xforms:label> 
                <xforms:itemset 
nodeset="instance('accessibility-instance')/accesstype"> 
                      <xforms:label ref="accessterm"/> 
           <xforms:copy ref="accessibility"/> 
           <xforms:action ev:event="xforms-select"> 
                 <xforms:insert bind="metadata" at="last()" 
position="after"/> 
                            <xforms:setvalue ref="."/> 
                      </xforms:action> 
                </xforms:itemset> 
</xforms:select> 

However this produces some pretty mangled results and I'm not at all 
sure what the bindings should really look like in this case. 

Any pointers you (or anyone else) can offer would be much appreciated. 

P.S. accessibility.xml attached in case required. 

Many Thanks 
Rob Walpole 
Devon Portal Developer 
Email robert.walpole@devon.gov.uk 
Web http://www.devonline.gov.uk 



> -----Original Message----- 
> From: www-forms-request@w3.org 
> [mailto:www-forms-request@w3.org] On Behalf Of Aaron Reed 
> Sent: 19 October 2007 21:53 
> To: www-forms@w3.org 
> Subject: Re: xforms:copy binding query 
> 
> 
> 
> Hi Rob, 
> 
> You can certainly bind two selects/select1s to the same node, 
> but when 
> you select items in a select/select1, it will replace the values 
> underneath it.  The only way you could mix and mingle them 
> are if both 
> selects had the same items and you use ctrl+<click> when 
> selecting items 
> (assuming your process uses a html:select type of control) but then 
> there isn't much reason to have both.  You could always try 
> to manage it 
> yourself with binding the two selects to different nodes and then 
> handling the xforms-select and xforms-deselect events and 
> inserting/deleting the nodes under the 'real' target node yourself. 
> 
> --Aaron 
> 
> Robert Walpole wrote: 
> > Hi, 
> > 
> > I am seeking some clarification about how the XForms copy element 
> > (http://www.w3.org/TR/2007/WD-xforms11-20070222/#ui-adv-copy) should 
> > work. 
> > 
> > My question is whether it should be possible to use xforms:copy on 
> > different xforms:select controls to copy different element 
> nodes into 
> > the same target node? 
> > 
> > For example, say I want to have 2 select controls that use use 
> > xforms:copy to populate the data node in the following... 
> > 
> > <test> 
> >                  <data/> 
> > </test> 
> > 
> > In this case I would bind both of my select controls to the 
> data nodeset 
> > and by selecting two values from both controls I would hope to get 
> > something like the following result... 
> > 
> > <test> 
> >                  <data> 
> >                                   <abc>123</abc> 
> >                                   <abc>456</abc> 
> >                                   <def>321</def> 
> >                                   <def>654</def> 
> >                  </data> 
> > </test> 
> > 
> > Is this allowable? It may be that I cannot bind two 
> different controls 
> > to the same target node. Any clarification of this would be much 
> > appreciated. 
> > 
> > Many Thanks 
> > Rob Walpole 
> > Devon Portal Developer 
> > Email robert.walpole@devon.gov.uk 
> > Web http://www.devonline.gov.uk 
> > 
> > 
> > 
> > 
> 
> 
> 
> 
Received on Tuesday, 23 October 2007 20:59:25 GMT

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