XML data access

Question

I've been looking at Spry now since it was announced trying
to figure out if I can use it for a project I'm starting. I love
the HTML markup nature and how it allows you to simplify they
creation of a page. It reminds me of Tapestry or Clay in how you
can imbed some custom HTML tags and don't have to recreate the
design of a page in JavaScript code.
I'm having a bit of trouble with the XML data flattening that
occurs and the selection model. It makes for some really nice
master-detail pages, but is too restrictive for other uses.
Here's what I'm wanting to do. I have this XML:
<group id="g1">
<app id="a1">
<os>Mac</os> <os>Windows</os>
</app>
<app id="a2">
<os>Linux</os> <os>AS400</os>
<app>
</group>
I'd like to end up with this result:
<dl>
<dt>a1<dt>
<dd><li>Mac</li>
<li>Windows</li></dd>
<dt>a2<dt>
<dd><li>Linux</li>
<li>AS400<li></dd>
</dl>
I want to display multiple levels of the XML at the same
time. Normally, I'd just loop through the list of APP's, and then
loop through the list of OS's to create this. But because of the
way Spry flattens XML data and doesn't make available children, I
can't get the behavior I want. When I load in this XML, I could
subsequently run through the list of applications, create new data
sets for each application getting the OS items, and add the dataset
as an item to each row in the APP's dataset or stick it in some
other associative array. But I haven't been able to figure out how
to access that information in a loop inside a loop. For all I know,
there isn't even a way to have a loop inside a loop.
What I really need / want is to be able to access any value
in my XML document at any time. I envision the markup to achieve
what I want as something like this:
var dsApps = new Spry.Data.XMLDataSet(url, '/app'); // <--
specifying URL would give me an array of the XML nodes for that
path
<span spryregion="dsApps">
<dl>
<!-- have added 'spryvalue' which applies a label to the
iteration value -->
<span spryrepeatchildren="dsApps" spryvalue="app">
<!-- Access to data could be one of three ways
'dataset:label:path', 'label:path', or 'path' with parts that are
left out being automatically calculated from current environment
-->
<dt>{dsApps:app:@id} {app:@id} {@id} - all should be
same</dt>
<!-- Here we want to iterate over the OS items below the
current app node. We identify this with the form 'path' value.
Repeats would presume you are specifying a dataset, not a path
-->
<dd spryrepeatchildren='app:os">
<!-- I can specify a value from a my parent loop, and the
{os} defaults to the current loop -->
<li>{app:@id} - {os}</li>
</dd>
</dl>
</span>
I don't have all the answers, but if I could access any data
in the XML document, that would just seem to allow more complicated
XML structures without resorting to numerous tricks or just being
completely unable to do what I want.
-d

Answer 1

I can't send the file as it indeed does hold confidential
data, however the expressions I was using were:
var dsActivities = new Spry.Data.XMLDataSet("activities.xml",
"activities/activity");
var dsActivityDetails = new
Spry.Data.XMLDataSet("activities.xml", "activities/activity[title =
'{dsActivities::title}']");
var dsAudience = new Spry.Data.XMLDataSet("activities.xml",
"activities/activity[title =
'{dsActivities::title}']/audiences/audience");
And a snippet of the XML:
<?xml version="1.0"?>
<activities lastUpdated="3/20/2006">
<activity>
<activityID>1</activityID>
<title>Foo</title>
<dateUpdated>1/11/2006</dateUpdated>
<themes>
<theme>foo</theme>
<theme>bar</theme>
</themes>
<keywords>
<keyword>foo</keywordsItem>
<keyword>bar</keyword>
</keywords>
<category>Foo</category>
<type>Bar</type>
<audiences>
<audience>Foo</audience>
<audience>Bar</audience>
<audience>Baz</audience>
</audiences>
<cost>$1</cost>
<links>
<link title="Foo" location="foo.pdf"></link>
<link title="Bar" location="bar.pdf"></link>
</links>
<examples>
<example sector="foo" title="Foo"
location="foo.html"></example>
<example sector="bar" title="Bar"
location="bar.html"></example>
</examples>
<description><![CDATA[The quick brown fox
jumped.]]></description>
</activity>
<activity>
</activity>
</activities>