[Laszlo-dev] loading of datasets within a view ?

[ddwoske at loraxis.com]

Newbie here.  I know so little, I don't even know how to properly title
this thread.

My data is in several xml files and I want to combine them and look at a
summary table.

I want to see this:

id       study       experiment     status
-----------------------------------------------
1053     myStudy     MyExperiment   pending
1054     myStudy2    MyExperiment2  pending
1        myStudy3    MyExperiment3  inprogress
...

Top level file named queue.xml .. looks like this:

<?xml version="1.0" encoding="UTF-8"?>
<queue>
	<status value="pending">
		<request id="1053" />
		<request id="1054" />
	</status>
	<status value="inprogress">
		<request id="1" />
		<request id="2" />
		<request id="3" />
	</status>
</queue>

And the details of each request are in different files based on their id. 
For now, let's just look at a file called basics.xml.

E.G.  This lives in directory requests/1053 where 1053 is the request id.
requests/1053/basics.xml

in there, we have:

<?xml version="1.0" encoding="UTF-8"?>
<request>
    <id>1</id>
    <status>pending</status>
    <experiment>MyExperiment</experiment>
    <study>MyStudy</study>
</request>

I want to change the src of the 'details' dataset depending on which item
in the queue I am currently looking at.  My first (and feeble) attempt is
this, which doesn't work for several reasons.  I apparently can't nest a
script tag like that, and the requests/@id/basics.xml doesn't do the XPath
substitution.  Obviously I have no idea what I'm doing.

<canvas>
  <dataset name="dset" src="queue.xml"/>
  <dataset name="basics" src="stubbed-out-until-i-know-what-to-load"/>

<simplelayout axis="y"/>

  <view datapath="dset:/queue/status/request">
     <script>
         var d = canvas.datasets.basics;
         d.setAttribute('src', 'requests/@id/basics.xml"/>
     </script>

    <simplelayout axis="x"/>
    <text datapath="@id"/>
    <text datapath="basics:/request/study"/>
    <text datapath="basics:/request/experiment"/>
    <text datapath="basics:/request/status"/>
  </view>
</canvas>

I couldn't find any examples to help me along these lines, and I just
don't have any idea about how to override methods, or plug into hooks, or
whatever it takes to get this done.

Thanks for any help.

Donald