(jeffa) Re: XML::Dumper

I am starting to think that this is a bug in XML::Dumper. I followed the Perl debugger and found this oddity:

...

main::(foo.pl:16): $config = $dumper->xml2pl($xml);
  DB<1> s
XML::Dumper::xml2pl(.../XML/Dumper.pm:114):
114:     my ($obj,$tree) = @_;
  DB<1> n
XML::Dumper::xml2pl(.../XML/Dumper.pm:117):
117:     my $TopItem = $tree->[1];
  DB<1> n
XML::Dumper::xml2pl(.../XML/Dumper.pm:118):
118:     my $ref = &Undump($TopItem);
  DB<1> s
XML::Dumper::Undump(.../XML/Dumper.pm:133):
133:     my ($Tree) = shift;
  DB<1> n
XML::Dumper::Undump(.../XML/Dumper.pm:134):
134:     my $ref = undef;
  DB<1> n
XML::Dumper::Undump(.../XML/Dumper.pm:135):
135:     my $FoundScalar;
  DB<1> n
XML::Dumper::Undump(.../XML/Dumper.pm:136):
136:     my $i;
  DB<1> n
XML::Dumper::Undump(.../XML/Dumper.pm:138):
138:     for ($i = 1; $i < $#$Tree; $i+=2) {  
  DB<1> n
XML::Dumper::Undump(.../XML/Dumper.pm:178):
178:     $ref = $FoundScalar unless defined($ref);
  DB<1> n
XML::Dumper::Undump(/.../XML/Dumper.pm:180):
180:   done:
181:     return ($ref);
  DB<1> n
XML::Dumper::xml2pl(/.../XML/Dumper.pm:120):
120:     return($ref);
  DB<1> n
main::(foo.pl:21): print Dumper $config;
[download]

The problems i see are on lines 117 and 138 of XML/Dumper.pm. The code expects the argument to xml2pl to be an array ref, when it is really a scalar. The result is the for loop not being entered, and eventually an undef is returned.

Additionally, the synopsis code is inconsistent (if not broken) and once i 'fixed' and ran it, it produced the same results as your script - undef for the return value of xml2pl.

Personally, i'd just use XML::Simple. There maybe more configuration options to worry about, but i also think that you should worry about those config options.

My apologies in advance to the author of XML::Dumper if i am wrong. If nobody tells me contrary within about 24 hours then i will notify the author.

Update - i received a /msg from blakem that stated the same conclusion.

jeffa

L-LL-L--L-LL-L--L-LL-L--
-R--R-RR-R--R-RR-R--R-RR
B--B--B--B--B--B--B--B--
H---H---H---H---H---H---
(the triplet paradiddle with high-hat)

Comment on (jeffa) Re: XML::Dumper Download Code

Replies are listed 'Best First'.
Re: (jeffa) Re: XML::Dumper by theguvnor (Chaplain) on Jan 21, 2002 at 00:45 UTC
++jeffa. Thanks for confirming that I'm not the only one who can't make it work as advertised. I did briefly take a look at the .pm file to see if I could see anything obviously broken, but alas I was not. (But I also noticed the documentation was a little, er, inconsistent.) Hopefully the author will correct the problem, if it truly is a bug as jeffa's analysis points to. I have indeed fallen back to using XML::Simple. Thanks again.	[reply]
(jeffa) 2Re: XML::Dumper by jeffa (Bishop) on Dec 09, 2002 at 16:04 UTC
... nearly one year later ... I received an email from the new maintainer of XML::Dumper, Mike Wong, yesterday (2002-12-09). This bug has been fixed. :) Also, Mike has added more features such as handling circular references, the ability to read and write zlib-compressed XML, and some more (check out the Changes file that ships with the tar ball for more). Here is the output from theguvnor's code using XML::Dumper 0.59: [jeffa@trinity perl]$ ./foo.pl xml output: <perldata> <hashref memory_address="0x8108634"> <item key="a key">a value</item> <item key="another key">another value</item> </hashref> </perldata> jeffa L-LL-L--L-LL-L--L-LL-L-- -R--R-RR-R--R-RR-R--R-RR B--B--B--B--B--B--B--B-- H---H---H---H---H---H--- (the triplet paradiddle with high-hat)	[reply]