XML::Parser XML validation

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

Dear Perlmonks,
I would like the below script to outpout all XML errors and not stop at the first instance only:

#!/usr/bin/perl
use XML::Parser;
 
my $xmlfile = shift @ARGV;              # the file to parse
 
# initialize parser object and parse the string
my $parser = XML::Parser->new( ErrorContext => 2 );
eval { $parser->parsefile( $xmlfile ); };
 
# report any error that stopped parsing, or announce success
if( $@ ) {
    $@ =~ s/at \/.*?$//s;               # remove module line number
    print STDERR "\nERROR in '$xmlfile':\n$@\n";
} else {
    print STDERR "'$xmlfile' is well-formed\n";
}
[download]

How could this be achieved? Thanks

Comment on XML::Parser XML validation Download Code

Replies are listed 'Best First'.
Re: XML::Parser XML validation by choroba (Cardinal) on Jan 05, 2013 at 11:32 UTC
The parser cannot know how to fix the first error it finds. The other errors, therefore, might lack information value. Consider the following document: `<r> <a> <b> <c> </b> </a> </r>` [download] The problem is the missing `</c>`. But the parser might tell you: `Start and end tag mismatch: c and b, line 5. Start and end tag mismatch: b and a, line 6. Start and end tag mismatch: a and r, line 7. Unexpected end of the document, line 7.` [download] BTW, that's roughly what `xmllint` would tell you. لսႽ† ᥲᥒ⚪⟊Ⴙᘓᖇ Ꮅᘓᖇ⎱ Ⴙᥲ𝇋ƙᘓᖇ	[reply] [d/l] [select]
Re^2: XML::Parser XML validation by Anonymous Monk on Jan 05, 2013 at 11:35 UTC
Thanks for your quick answer. So basically, I will have to fix any error found by the script and then re-run, fix any new error and repeat the procedure until there are no more errors?	[reply]
Re^3: XML::Parser XML validation by CountZero (Bishop) on Jan 05, 2013 at 13:47 UTC
Yes. All bets are off for an XML document with errors. The first error found may actually not be the first error in the document: it is just the place where the parser got stuck. Consider the following: `<a> <d> <e> </e> </b> </a>` [download] Where is the error? Should `<d>` be `<b>` or should `</b>` be `</d>`? Or perhaps they should both be `<f> ... </f>` tags? How is the parser to know? To be sure the XML is not only well formed but also correct, you will have to validate the XML according to a DTD or Schema definition. CountZero A program should be light and agile, its subroutines connected like a string of pearls. The spirit and intent of the program should be retained throughout. There should be neither too little or too much, neither needless loops nor useless variables, neither lack of structure nor overwhelming rigidity." - The Tao of Programming, 4.1 - Geoffrey James My blog: Imperial Deltronics	[reply] [d/l] [select]
Re: XML::Parser XML validation by Anonymous Monk on Jan 05, 2013 at 12:43 UTC
Don't go looking to reinvent xmllint, go looking how to install xmllint	[reply]
Re: XML::Parser XML validation by karlgoethebier (Abbot) on Jan 05, 2013 at 17:25 UTC
See also XML validation. Best regards, Karl «The Crux of the Biscuit is the Apostrophe»	[reply]

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