XML processing

Fellow Monks,

After a lot of documentation reading and testing and spending almost 2 days trying to understand XML:Parser module I finally have to ask for some help here.

I receive some data in a XML file and am required to extract part of the data

<rootNode>
  <a>
    ...text + other XML
  </a>

  <a>
      ...text + other XML
  </a>
</rootNode>
[download]

Now I need to extract all information between

<a> and </a>
[download]

tags and I need to do this using XML:Parser.
Any suggestions on how I could do this ?
below is my non-working code:
===============================================

use XML::Parser;

my $XmlFile = "foo.xml";
die "Can't find file \"$XmlFile\"" unless -f $XmlFile;


my $pFoundFlag = 0;
my $NewFile;

my $parser = new XML::Parser(Style => 'Debug');

$parser->setHandlers(    Start => \&startElement(),
                        Char => \&char_handler(),
                        End   => \&end_Handler,
                      );

$parser->parsefile($XmlFile);


sub startElement {
    my ($parserInst, $element, %attr) = @_;
        
    if ($element eq "a") {
        $pFoundFlag = 1;
    }
    
    if ($pFoundFlag) {
        
        if(not $NewFile) {
            $NewFile = $element;    
        } else {        
            $NewFile .= $element;                
        }
    }
                    
    
}

sub char_handler {
    my ($parserInst, $data);
        
    if ($pFoundFlag) {
        $NewFile .= $data;                    
    }
    
}

sub end_Handler {
    my ($parserInst, $element);
    
    if ($pFoundFlag) {
        $NewFile .= $element;                    
    }
    
    if ($element eq "a") {
        $pFoundFlag = 0;
    }

}


$OpFile = "foo_outpur.xml";
open (OP, ">$OpFile") or die ("can't open output file!");

    print OP $NewFile;

close(OP);

[download]

================================================

Comment on XML processing Select or Download Code
Re: XML processing by borisz (Canon) on Aug 05, 2005 at 22:55 UTC
Do yourself a favor and use another Modul to Filter your XML. I suggest XML::Twig or XML::SAX. The tool xml_grep from XML::Twig does exactly what you want. `xml_grep a your_xmlfile.xml` [download] Boris	[reply] [d/l]
Re: XML processing by Tanktalus (Canon) on Aug 06, 2005 at 02:44 UTC
Seconding borisz's advice, here's some (untested) XML::Twig code to do this, in case you want to continue doing stuff with the results in perl: `use XML::Twig; # ... my $twig = XML::Twig->new(); $twig->parsefile($XmlFile); my @a_elements = $twig->get_xpath("//a"); foreach my $el (@a_elements) { my $text = $el->text(); # do stuff with $text. }` [download] It's actually pretty easy, once you know which APIs you want ;-) Update: Changed loop variable from $a to $el when reminded by graff. Tks.	[reply] [d/l]
Re^2: XML processing by graff (Canon) on Aug 06, 2005 at 16:24 UTC
But it would be better not to use "$a" as the name of the iterator variable in the "for" loop, in case "doing stuff" includes using "sort".	[reply]
Re^2: XML processing by shreya (Novice) on Aug 10, 2005 at 22:31 UTC
Borisz, I started using XML:Twig. However facing a problem. `my $twig = XML::Twig->new(twig_handlers => {a'=> \&Test ); # Parse the file $twig->parsefile($XmlFile); # Handler sub routine sub Test { my ($parser, $element) = @_; # This prints element <a> along with its contents to some out +put file $element->print(\OP); # However What I really want done over here is have element <a> a +long with its subelements and text be copied to another variable inst +ead of being printed on screen }` [download] Problem*: What I really want done over here is have element along with its subelements and text be copied to another variable instead of being printed on screen Something like $ElementA .= $element->print; Pls advice. Thanks,	[reply] [d/l]
Re^3: XML processing by mirod (Canon) on Aug 10, 2005 at 23:13 UTC
something like `$ElementA .= $element->sprint;`?	[reply] [d/l]
Re^3: XML processing by shreya (Novice) on Aug 11, 2005 at 19:07 UTC
Thanks Mirod. This worked. I am still trying to get used to this response method. Didnt realise that someone replied ot my old posts. Wish there was a way to notify by email when someone replies to your posts. Later	[reply]
Re^4: XML processing by runrig (Abbot) on Aug 11, 2005 at 19:11 UTC
Re: XML processing by mrborisguy (Hermit) on Aug 06, 2005 at 03:26 UTC
`sub char_handler { my ($parserInst, $data);` [download] `sub end_Handler { my ($parserInst, $element);` [download] You may want to include the important `= @_` here as well. -Bryan	[reply] [d/l] [select]
Re: XML processing by shreya (Novice) on Aug 08, 2005 at 13:50 UTC
Thanks borisz, Tanktalus, graff and mrborisguy for your comments. I did a little bit of reading on XML::Twig before posting. However I really wanted to use XML:Parser instead of XML:Twig. I dont have rights to install modules on our company server. i guess for now I am going to run XML::Twig from my own directory since I need to get a demo by EOD. Thanks again guys.	[reply]
Re: XML processing by shreya (Novice) on Aug 10, 2005 at 22:59 UTC
I started using XML:Twig. However facing a problem. `my $twig = XML::Twig->new(twig_handlers => {a'=> \&Test ); # Parse the file $twig->parsefile($XmlFile); # Handler sub routine sub Test { my ($parser, $element) = @_; # This prints element <a> along with its contents to some out +put file $element->print(\*OP); # However What I really want done over here is have element <a> a + long with its subelements and text be copied to another variable ins +tead of being printed on screen }` [download] Problem: What I really want done over here is have element along with its subelements and text be copied to another variable instead of being printed on screen Something like $ElementA .= $element->print; Pls advice. Thanks,	[reply] [d/l]


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XML processing

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