Parsing XML with XML::Simple

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

Monks,

I have been at this for much longer than should be necessary. I am using XML::Simple, but I have also unsuccessfully tried XML::Twig. The file (with an example below) I have a file that looks like what is below. Each tag is only used once. I know it is possible to use a few regexen, but the way I need to use the data later, having the data in a hash similar to one returned by XML::Simple.

<CVS>
$Id: File_Find.pl,v 1.1 2006-12-17 19:25:03 eric Exp $
This That <this@that.com>
Desc: Test file
</CVS>
<DATE>2006-12-10</DATE>
<INTRODUCTION>Blah, <b>blah</b>, blah</INTRODUCTION>
<TITLE>Foo</TITLE>
<AUTHOR>Bar</AUTHOR>
...
<ARTICLE>
<p>foo, test</p>
<p>bar</p>
<p>baz</p>
</ARTICLE>
[download]

When I have the above text, all I get is what's inside of <CVS>. When I add <XML> tags surrounding the whole file, all I get is the following using Data::Dumper:

$VAR1 = \{
            'CVS' => '<The entire file and this is the only tag in the
+ hash with no other tags even making it in here>'};
[download]

What is the best method to extract the data out of this file (either using an XML module or not) and pulling out what I need into a hash? Thanks.

Update: I forgot to include the code I actually tried. I know the $file is correct and @articles is populated.

   foreach my $file (@articles) {
     my $article = XMLin($file, NoAttr => 1);
     use Data::Dumper;
     print "<pre>", Dumper(\$article), "</pre>";
   }
[download]

Update 2: I think I need to provide a better example of the data. So look above at the data example and that gives a much better perception of what I am dealing with.

Comment on Parsing XML with XML::Simple Select or Download Code

Replies are listed 'Best First'.
Re: Parsing XML with XML::Simple by ferreira (Chaplain) on Dec 18, 2006 at 00:54 UTC
The problem is that you don't have a well-formed XML file. If it were well-formed, there would be a root element, which is the ancestral of every other ones. Something like this: `<root> <CVS> $Id: File_Find.pl,v 1.1 2006-12-17 19:25:03 eric Exp $ </CVS> <DATE>2006-12-10</DATE> ... <ARTICLE> foo bar baz </ARTICLE> </root>` [download] I think if you do this simple correction, XML::Simple will work right for you. And, by the default, this root element disappears, so that you'll get at the first level a hash with the keys you want: CVS, ARTICLE, DATE, etc. You could always try your XML files against a typical browser (like FireFox, Opera, IE, etc.) to see if they are well-formed or if some error is pointed.	[reply] [d/l]
Re^2: Parsing XML with XML::Simple by madbombX (Hermit) on Dec 18, 2006 at 01:03 UTC
You hit the nail on the head. Everything I had worked just fine. The problem is that when I ran it through Firefox, I noticed that a few points throughout the articles, I have the author emails in the following format: `First Last <this@that.com>` [download] That messed everything up and all my original code actually works. Is there a way around that using XML::Simple or XML::Twig so that I don't have to go through EVERY file and remove all instances of that?	[reply] [d/l]
Re^3: Parsing XML with XML::Simple by ferreira (Chaplain) on Dec 18, 2006 at 01:14 UTC
The big issue is that if you have `First Last <this@that.com>` within your XML, you have bad XML. (It should be `First Last <this@that.com>`.) It is better to fix these files. I am not sure how you came into this, because XML::Simple usually escapes these things: `$ perl -MXML::Simple -e "print XMLout({ a => 'a <b>' })" <opt a="a <b>" />` [download] It could be the version you're using. The example above used `$ which_pm XML::Simple XML::Simple 2.13 c:/tools/apache/Perl/site/lib/XML/Simple.pm` [download]	[reply] [d/l] [select]
Re^4: Parsing XML with XML::Simple by madbombX (Hermit) on Dec 18, 2006 at 01:22 UTC
Re^5: Parsing XML with XML::Simple by GrandFather (Saint) on Dec 18, 2006 at 01:30 UTC
Re^5: Parsing XML with XML::Simple by Jenda (Abbot) on Dec 18, 2006 at 21:12 UTC
Re: Parsing XML with XML::Simple by GrandFather (Saint) on Dec 18, 2006 at 00:54 UTC
XML::Twig seems to do what you want if you Simplify things a little: `use strict; use warnings; use XML::Twig; use Data::Dump::Streamer; my $twig = XML::Twig->new (); $twig->parse (*DATA); my $hash = $twig->simplify (); Dump ($hash); __DATA__ <XML> <CVS> $Id: File_Find.pl,v 1.1 2006-12-17 19:25:03 eric Exp $ </CVS> <DATE>2006-12-10</DATE> <INTRODUCTION>Blah</INTRODUCTION> <TITLE>Foo</TITLE> <AUTHOR>Bar</AUTHOR> ... <ARTICLE> foo bar baz </ARTICLE> </XML>` [download] Prints: `$HASH1 = { ARTICLE => "\nfoo bar baz\n", AUTHOR => 'Bar', content => "\n\$Id: File_Find.pl,v 1.1 2006-12-17 19:25:03 e +ric Exp \$\n2006-12-10BlahFo". "oBar\n...\n\nfoo bar baz\n", CVS => "\n\$Id: File_Find.pl,v 1.1 2006-12-17 19:25:03 e +ric Exp \$\n", DATE => '2006-12-10', INTRODUCTION => 'Blah', TITLE => 'Foo' };` [download] DWIM is Perl's answer to Gödel	[reply] [d/l] [select]
Re: Parsing XML with XML::Simple by brian_d_foy (Abbot) on Dec 18, 2006 at 00:53 UTC
This seems to work for me. You mentioned wrapping a root element around it, but did you include the `<?xml ...?>` bit? Even when I remove that, though, it still works. Does it fail with your sample file? `#!/usr/bin/perl use XML::Simple; my $xml = do { local $/; <DATA> }; my $hash = XMLin( $xml ); use Data::Dumper; print Dumper( $hash ); __END__ <?xml version="1.0"?> <root> <CVS> $Id: File_Find.pl,v 1.1 2006-12-17 19:25:03 eric Exp $ </CVS> <DATE>2006-12-10</DATE> <INTRODUCTION>Blah</INTRODUCTION> <TITLE>Foo</TITLE> <AUTHOR>Bar</AUTHOR> <ARTICLE> foo bar baz </ARTICLE> </root>` [download] It looks like the hash does what it should: `]$ perl test $VAR1 = { 'INTRODUCTION' => 'Blah', 'CVS' => ' $Id: File_Find.pl,v 1.1 2006-12-17 19:25:03 eric Exp $ ', 'ARTICLE' => ' foo bar baz ', 'TITLE' => 'Foo', 'AUTHOR' => 'Bar', 'DATE' => '2006-12-10' };` [download] Update: If I move the data out to a file and use `XMLin( $ARGV[0], NoAttr => 1 )` it still works. -- brian d foy <brian@stonehenge.com> Subscribe to The Perl Review	[reply] [d/l] [select]


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