Hi monks,

XML::xpath is making my brain ache, perhaps someone can enlighten me.

It's taken a while but I think I'm starting to understand the differences between a nodeset and a node list. I'm sure I've not got it fully because my code so far is not that nice.

What I'm doing is getting a nodeset using find(), for example:

my $xp = XML::XPath->new(filename => $file);
$plantdata->{nodeset} = $xp->find('//loop_device[@loop_number="1"]');

[download]

I then run though the nodes like this

foreach my $device ($plantdata->{nodeset}->get_nodelist()) {
  $devicename = find('devicename')->string_value;
  $devicetype = find('devicetype')->string_value;

  do more stuff
}

[download]

Most of the time I'm just getting attributes as in the above code and chucking them out to an Excel spreadsheet but for a few values of $devicetype I need to dig deeper into the XML and this is where I'm stuck.

What I've done is go back to the beginning like this:

if ($devicetype eq "complex") {
  $seachstring = sprintf "//loop_device[@devicename=\"%s\"]/subdevice"
+, $devicename;
  $subdevice = $xp->find($searchstring);
}

[download]

I'm doing this because $device is a node from a node list not from a nodeset so I can't do this:

$subdevice = $device->find('/subdevice');

[download]

If I go into the debugger and look at $plantdata->{nodeset} and $device both seem to contain a hell of a lot more than just the node I want. Is there a way to turn a $device node back into a nodeset so that I can dig deeper into it rather than going back to $xp and starting again?

Thanks
Nonk

In reply to nodelists and nodesets by nonnonymousnonk

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