XML::XPath tricks and tips

dstefani has asked for the wisdom of the Perl Monks concerning the following question:

Hello, New to XML and need to use it, I know... Here is a sample of my XML:

<AvailableBatch>
  <Date>08/31/2004</Date>
  <Available>
    <Sku>40</Sku>
    <Part>10                  </Part>
    <Location>20</Location>
    <Qty>1</Qty>
    <Time>18:38:01</Time>
  </Available>
  <Available>
    <Sku>40</Sku>
    <Part>10                  </Part>
    <Location>60</Location>
    <Qty>0</Qty>
    <Time>18:38:01</Time>
  </Available>
</AvailableBatch>
[download]

I need to treat each <Available> grouping as a record and get the <Part> and <Qty> for each, then test each record against a MySQL table.

Below is attempt to try and use XML::Path, some code I gleaned from Perl / XML.

I can see how to get one element, but I could use a hint at how to group the child elements. The samples I see all count of the elements having attributes, which my file does not use.

Thanks, I hope I'm not too far to the "help me write me script" side, I just need a good hint or two.

use XML::XPath;

my $file = 'available_batchnyyn.xml';
my $xp = XML::XPath->new(filename=>$file);


my $nodeset = $xp->find('//Sku');

my @zipcodes;                   # Where we'll put our results
if (my @nodelist = $nodeset->get_nodelist) {
  
  @zipcodes = map($_->string_value, @nodelist);

  
  @zipcodes = sort(@zipcodes);
  local $" = "\n";
  print "I found these zipcodes:\n@zipcodes\n";
} else {
  print "The file $file didn't have any 'zip' elements in it!\n";
}
[download]

-dstefani

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Re: XML::XPath tricks and tips by mirod (Canon) on Sep 02, 2004 at 00:18 UTC
I can't really see what your code is supposed to do, what's with the zipcodes? Here is an example of how to get data from a file using XML::XPath: `#!/usr/bin/perl -w use strict; use XML::XPath; my $file = 'available_batchnyyn.xml'; my $xp = XML::XPath->new(filename=>$file); # /AvailableBatch/Available is faster than //Available my @available = $xp->findnodes('/AvailableBatch/Available'); foreach my $available (@available) { my $part= $available->findvalue( './Part[1]'); # the [1] is not re +ally needed my $qty= $available->findvalue( './Qty[1]'); $part=~ s{\s+$}{}; # you might need to + trim all values print "part $part - qty: $qty\n"; }` [download]	[reply] [d/l]
Re: XML::XPath tricks and tips by Aristotle (Chancellor) on Sep 02, 2004 at 00:16 UTC
Disclaimer: I've never used XML::XPath and don't even have it installed. I'm writing this from a quick glance at the documentation and my experience working with XML::LibXML. You should get the idea. `for my $available ( $xp->findnodes( '//Available' ) ) { my $qty = $available->findvalue( 'Qty' ); my $part = $available->findvalue( 'Part' ); # ... }` [download] The important part is to realize that the XPath expressions passed to `$available->findvalue()` will be evaluated relative to the node `$available` represents. Makeshifts last the longest.	[reply] [d/l]
Re: XML::XPath tricks and tips by johnnywang (Priest) on Sep 02, 2004 at 00:26 UTC
A similar, actually more complex, question was asked in Help with XML::XPath, where I gave a few code samples.	[reply]
Re: XML::XPath tricks and tips by gmpassos (Priest) on Sep 02, 2004 at 16:03 UTC
If you want to just access XML values you don't need to use XPath to find this informations. You can use it, but the XPath implementation in Perl (XML::XPath), in my opinion, is not very intuitive to use. What you can do is to use some module that loads XML into a HASH tree, and access the values directly from the tree. You can take a look at XML::Simple (more popular) and XML::Smart (well, I'm the author of it, so I shouldn't say what is better). Well, the main idea of XML::Smart is to enable the use of XML by programmers without need to really know the XML format. Here's a simple example of how to do what you want: `use XML::Smart ; my $xml = new XML::Smart('available_batchnyyn.xml'); my @avaliables = @{ $xml->{AvailableBatch}{Available} } ; foreach my $avaliables_i ( @avaliables ) { my $part = $avaliables_i->{Part} ; my $qty = $avaliables_i->{Qty} ; print "Part: $part ; Qty: $qty\n" ; }` [download] Graciliano M. P. "Creativity is the expression of the liberty".	[reply] [d/l]