Menus, NestedXMLDataSet and detailregion

Question

www.nurseryabingercommon.org
is using a simple xml dataset for proof of concept (see below) and
SpryNestedXMLDataSet.js - version 0.4 - Spry Pre-Release 1.6.
Testing is being performed with IE7
www.nurseryabingercommon.org
is based on the Adobe nested XML dataset and menubar example with
the addition of the selection updating a detailregion. The results
of selecting items from the sub-menus are anomalous. An example
problem is after opening the page, a selection of 'Item 2.B' from
the sub-menu causes the detailregion to display 'content 2.A'
instead of 'content 2.B' (the correct association). If then 'Item
2.B' is reselected the correct result is obtained ('content 2.B' is
displayed), but then further selections on the other menus provide
incorrect updates of the detailregion.
I've tried tracking through the row requests through the code
to obtain the result, but I don't have enough background knowledge
of the code's design concepts to properly understand the processing
path and then to be able to generate a solution.
Any ideas or help is gratefully appreciated.
Thanks
Nigel
<?xml version="1.0" encoding="utf-8"?>
<events>
<event>
<heading><![CDATA[<strong>heading
1</strong>]]></heading>
<items>
<content ><![CDATA[<strong>content
1</strong>]]></content>
</items>
</event>
<event>
<heading>heading 2</heading>
<items>
<item >item 2.A</item>
<content >content 2.A</content>
</items>
<items>
<item >item 2.B</item>
<content >content 2.B</content>
</items>
</event>
<event>
<heading>heading 3</heading>
<items>
<item >item 3.a</item>
<content >content 3.A</content>
</items>
<items>
<item >item 3.b</item>
<content >content 3.B</content>
</items>
<items>
<item >item 3.c</item>
<content >content 3.C</content>
</items>
<items>
<item >item 3.d</item>
<content >content 3.D</content>
</items>
</event>
</events>

Answer 1

With further investigation I found the following problem:
When the request for the submenu is made, the new rowID is
initially stored into dsItems.currentDS (dsItems is the
Spry.Data.NestedXMLDataSet object), but then the processing calls
the NestedXMLDataSet function onCurrentRowchanged which nulls the
currentDS and currentDSAncestor and therefore the update
information is lost and the last times value of the rowID is
eventually used. I've made some (ugly) changes to
SpryNestedXMLDataSet.js to overcome this and which are specific to
support the functionality I need. The changes are:
Spry.Data.NestedXMLDataSet = function(parentDataSet, xpath,
options)
this.parentDataSet = parentDataSet;
this.xpath = xpath;
this.nestedDataSets = [];
this.nestedDataSetsHash = {};
this.currentDS = null;
this.currentDSAncestor = null;
this.options = options;
this.ignoreOnDataChanged = false;
this.entityEncodeStrings = parentDataSet ?
parentDataSet.entityEncodeStrings : true;
Spry.Data.DataSet.call(this, options);
parentDataSet.addObserver(this);
this.bufferedNewCurRowID = 0; // added to maintain a record
of a new request
Spry.Data.NestedXMLDataSet.prototype.getNestedDataSetForParentRow
= function(parentRow)
// Return the internal nested data set associated with the
parent's
// specified row object.
var xmlNode = parentRow.ds_XMLNode;
if (xmlNode && this.nestedDataSets)
// Before we go through all of the trouble of looking up the
data set
// we want, check to see if it is already our current data
set!
if (this.currentDSAncestor && this.currentDSAncestor
== xmlNode)
// Retrieve the buffered new row ID
this.currentDS.curRowID = this.bufferedNewCurRowID;
this.bufferedNewCurRowID = 0;
return this.currentDS;
Spry.Data.NestedXMLDataSet.prototype.setCurrentRow =
function(rowID)
if (this.currentDS)
// Buffer the request, as this.currentDS may be destroyed
this.bufferedNewCurRowID = rowID;
return this.currentDS.setCurrentRow(rowID);
The HTML file was modified to complete the reset -
from:
<li spry:repeat="dsNursery" spry:setrow="dsNursery">
<a class="MenuBarItemSubmenu" href="#"
spry:if="{dsItems::ds_RowCount} > 1">{heading}</a>
<a href="#" spry:if="{dsItems::ds_RowCount} ==
1">{heading}</a>
to:
<li spry:repeat="dsNursery" spry:setrow="dsNursery">
<a class="MenuBarItemSubmenu" href="#"
spry:if="{dsItems::ds_RowCount} > 1"
onclick="dsItems.bufferedNewCurRowID = 0;">{heading}</a>
<a href="#" spry:if="{dsItems::ds_RowCount} == 1"
onclick="dsItems.bufferedNewCurRowID =
0;">{heading}</a>