RE: MARC::Field-subfields function
And what field are you pulling? Does it have subfields? Are you sure you're using the same variable? Seeing more of your code might make it easier to guess. Not all marc fields have to have subfields. Not sure what MARC::Field returns if it does not have any. If it returns undefined, that could probably cause problems if you're iterating over a record and there's a field without subfields. (Like the leader/fixed fields?). Others might have more ideas off the top of their head, but I figured I'd jot off a quick response just in case. Jon Gorman -Original Message- From: Justin Rittenhouse [mailto:jritt...@nd.edu] Sent: Wednesday, September 08, 2010 3:51 PM To: perl4lib@perl.org Subject: MARC::Field-subfields function I'm relatively new to Perl and very new to the MARC::Record module. I'm trying to use the subfields function (my @subfields = $field- subfields();), but I'm getting an error: Can't use an undefined value as an ARRAY reference at /usr/lib64/perl5/vendor_perl/5.8.8/MARC/Field.pm line 275. I'm not familiar enough with Perl to figure out what the function is actually doing, so I can't figure out if this is a bug or if I missed something in the tutorial. Other functions off of the $field variable work (I can pull the tag, indicator, and as_string functions). Any thoughts are appreciated. Justin -- Justin Rittenhouse Systems Support Library Systems Department Hesburgh Libraries http://www.library.nd.edu/ (574) 631-3065
Re: MARC::Field-subfields function
Hi, On Thu, Sep 9, 2010 at 5:57 AM, Colin Campbell colin.campb...@ptfs-europe.com wrote: On 08/09/10 22:07, Justin Rittenhouse wrote: Taking a look at MARC/Field.pm there's a bit of shaky error handling. subfields checks to see if its a control field, warns that it is then proceeds to try and return the non-existent array. It should just return at that point. I'll take a look at creating a patch for that. I have applied this patch. There aren't enough changes yet to do another CPAN release of MARC::Record, but anybody who wants to use the latest and greatest can always grab it from the Git repository: git://marcpm.git.sourceforge.net/gitroot/marcpm/marcpm Regards, Galen -- Galen Charlton gmcha...@gmail.com
RE: MARC::Field-subfields function
On Wednesday, September 08, 2010 3:51 PM, Justin Rittenhouse
[mailto:jritt...@nd.edu] wrote:
I'm relatively new to Perl and very new to the MARC::Record module. I'm
trying to use the subfields function (my @subfields = $field-subfields();),
but I'm getting an error:
Can't use an undefined value as an ARRAY reference at
/usr/lib64/perl5/vendor_perl/5.8.8/MARC/Field.pm line 275.
I'm not familiar enough with Perl to figure out what the function is actually
doing, so I can't figure out if this is a bug or if I missed something in the
tutorial. Other functions off of the $field variable work (I can pull the
tag, indicator, and as_string functions).
It's difficult to say what went wrong without a little more context. In
MARC::Lint, to access the subfields of a field, the following code appears
fairly frequently to break down the subfields into code+data pairs in an array:
#where $field is a MARC::Field object
my @subfields = $field-subfields();
my @newsubfields = ();
while (my $subfield = pop(@subfields)) {
my ($code, $data) = @$subfield;
unshift (@newsubfields, $code, $data);
} # while
###
What does your code look like in the area that is producing the error?
Thank you,
Bryan Baldus
bryan.bal...@quality-books.com
eij...@cpan.org
http://home.comcast.net/~eijabb/
