How do I ignore comments in an xml file when using win32::ole?

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

I'm trying to parse the following xml file. It works for the most part, but bails out with an error when it hits the xml comments

<?xml version="1.0" encoding="UTF-8"?>
<Header>
    <Main id="1" name="Item1">
    </Main>
    <Main id="2" name="Item2">
    </Main>
    <!--Main id="3" name="Item4">
    </Main-->
    <Main id="4" name="Item5">
    </Main>
</Header>
[download]

This is my perl script I'm using to parse

use Win32::OLE qw(in with);

my $xml_file  = './test.xml';

my $dom = Win32::OLE->new('MSXML2.DOMDocument') or die "new() failed";

$dom->{async} = "False";
$dom->{validateOnParse} = "False";
$dom->Load($xml_file) or die "Parse failed";

my $Header = $dom->DocumentElement();
my $Mains = $Header->childNodes();

foreach my $main(in $Mains) {
   my $main_id = $main->Attributes->getNamedItem("id")->Text;
   my $main_name = $main->Attributes->getNamedItem("name")->Text;
   print "$main_id,$main_name\n";
}
[download]

This is the output it gives me, how do I make it ignore the sections that are commented out?
1,Item1
2,Item2
Can't call method "getNamedItem" on an undefined value at xml_try.pl line 15.

Comment on How do I ignore comments in an xml file when using win32::ole? Select or Download Code

Replies are listed 'Best First'.
Re: How do I ignore comments in an xml file when using win32::ole? by choroba (Cardinal) on Jun 25, 2011 at 15:20 UTC
Are you sure Win32::OLE is the right tool to parse xml? There are many XML tools available, like XML::LibXML, XML::Twig, XML::Simple, XML::XSH2, etc.	[reply]
Re: How do I ignore comments in an xml file when using win32::ole? by AnomalousMonk (Archbishop) on Jun 25, 2011 at 17:31 UTC
Correct me if I'm wrong (and I may very well be wrong for I have #$%&-all experience with XML or XML parsing), but it seems to me that `<!--Main id="3" name="Item4">` is not a proper XML comment and so maybe Win32::OLE is just choking and returning an undefined value when it encounters something that is, in fact, 'undefined' qua XML. (Would not `<!--Main id="3" name="Item4"``-->` be a proper comment: see '-->' at end?) Just curious.	[reply] [d/l] [select]
Re: How do I ignore comments in an xml file when using win32::ole? by toolic (Bishop) on Jun 25, 2011 at 17:53 UTC
Here is a Twig::XML solution: `use warnings; use strict; use XML::Twig; my $str = <<EOF; <?xml version="1.0" encoding="UTF-8"?> <Header> <Main id="1" name="Item1"> </Main> <Main id="2" name="Item2"> </Main> <!--Main id="3" name="Item4"> </Main--> <Main id="4" name="Item5"> </Main> </Header> EOF my $t = XML::Twig->new(twig_handlers => { Main => sub {print $_->att('id'), "\n"} }); $t->parse($str); __END__ 1 2 4` [download]	[reply] [d/l]
Re^2: How do I ignore comments in an xml file when using win32::ole? by ketanh (Novice) on Jun 25, 2011 at 19:37 UTC
@choroba, I'm a mere systems engineer trying to parse xml :) I've used xml::simple before, but that doesn't work with the file I have now. So I went with the search that gave me the easiest example to read and follow. @toolic, Thanks for the example. I didn't know what to do with the xml that you added into the code. I tried reading it in a few ways, didn't help. I have to read a file that I download from a repository and have to load it into my parser However, thanks to your example, I explored XML::TWIG more and figured out a way to do this. This link was very helpful http://www.xml.com/pub/a/2001/04/18/perlxmlqstart1.html `use warnings; use strict; use XML::Twig; my $file = './test.xml'; my $twig = XML::Twig->new(); $twig->parsefile($file); my $root = $twig->root; foreach my $item ($root->children('Main')){ print $item->att('id').", ".$item->att('name'); print "\n"; }` [download] This gave me the desired output. 1, Item1 2, Item2 4, Item5 @AnomalousMonk, I won't claim to be any sort of expert with xml. To me, if internet explorer grey'ed it out, and Visual SlickEdit "green"ed it out, I take it it's a comment in the XML. :) Thanks for all your help!	[reply] [d/l]
Re^3: How do I ignore comments in an xml file when using win32::ole? by toolic (Bishop) on Jun 25, 2011 at 19:45 UTC
I didn't know what to do with the xml that you added into the code. I tried reading it in a few ways, didn't help. I have to read a file that I download from a repository and have to load it into my parser XML::Twig is flexible in that it allows you to parse either a file (as you have done) or a Perl scalar variable (as I have done). Using the latter is merely for the convenience of creating a small self-contained code sample.	[reply]