How to extract attribute value in node using XPath

On Wed, 2007-10-03 at 17:15 -0700, Sunil wrote:
> Below is example code snippet which extracts NAME node
value. I want
> to extract MESSAGE node Type attribute value. 
> 
> XML FILE:
> 
> <MESSAGE Type="test">
>      <NAME>extract attribute value<NAME>
> </MESSAGE>
> 
> CODE SNIPPET:
> 
> foreach my $node (
$xmlFH->find("MESSAGE")->get_nodelist ) {
>                                                        
                                                            
        
>       my $name    =
$node->find("NAME")->string_value;
> 
> }
> 
> 
> Basically, I need to extract attribute value in a node
using XPath.
> How should I do that?

Most simply:

        use XML::XPath;
        
        my $xp = XML::XPath->new(filename =>
'xp1.xml');
        
        print $xp->findvalue('//MESSAGE/Type');


I've just used findvalue() there for convenience, you could
use find()
equally well but with the extra steps to get the value.

I'd recommend reading e.g. http://www.w3.org/TR/xpath
 and possibly such
as http://www.w3schools.
com/xpath/ 

/J
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On Wed, 3 Oct 2007, Sunil wrote:

> Below is example code snippet which extracts NAME node
value. I want to
> extract MESSAGE node Type attribute value.
>
> XML FILE:
>
> <MESSAGE Type="test">
>     <NAME>extract attribute value<NAME>
> </MESSAGE>
>
> CODE SNIPPET:
>
> foreach my $node (
$xmlFH->find("MESSAGE")->get_nodelist ) {
>
>
>      my $name    =
$node->find("NAME")->string_value;
>
> }
>
>
> Basically, I need to extract attribute value in a node
using XPath. How
> should I do that?

 	I'd be looking at something like

 	$xmlFH->findvalue('//MESSAGE/Type')

 	However, I recommend that you delve into XPath enough to
be able to 
resolve these kinds of problems.  Here are some tips:

1.	Use Data:umper to
print out the results of anything.  Often you'll
 	just get an object reference, but it'll tell you what type
of object
 	you're dealing with (ie. XML::LibXML::Attr vs.
XML::LibXML::Element).
2.	If you print the results of the serialize function, you
can see what's
 	in your node.  So, try something like this:


------------------------------------------------------------
-------------------
#!/usr/bin/perl

use	Data:umper;
use	Scalar::Util;

.......


$node = $xmlFH->find('whatever');
shownode($node);

sub	shownode {
 	my($node) = _;

 	print(('-' x 40) . "n");
 	print Dumper $node;
 	if(blessed($node) and $node->can('serialize')) {
 		print $node->serialize();
 	} else {
 		print "Can't serialize this!n";
 	}
 	print(('-' x 40) . "n");
}

------------------------------------------------------------
-------------------

 	That should point you towards any difficulties you
encounter.

 	


------------------------------------------------------------
---------
| Name: Tim Nelson                 | Because the Creator is,
       |
| E-mail: waylandsmartchat.net.au | I am                   
       |
------------------------------------------------------------
---------

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