fields()field( tagspec(s) )subfield( $tag, $subfield )append_fields( @fields )insert_fields_before( $before_field, @new_fields )insert_fields_after( $after_field, @new_fields )insert_fields_ordered( @new_fields )insert_grouped_field( $field )delete_field( $field )as_usmarc()as_formatted()leader()set_leader_lengths( $reclen, $baseaddr )clone()warnings()add_fields()
MARC::Record - Perl extension for handling MARC records
$Id: Record.pm,v 1.75 2003/12/16 19:31:59 petdance Exp $
Module for handling MARC records as objects. The file-handling stuff is in MARC::File::*.
None.
Any errors generated are stored in $MARC::Record::ERROR.
Warnings are kept with the record and accessible in the warnings() method.
new()Base constructor for the class. It just returns a completely empty record. To get real data, you'll need to populate it with fields, or use one of the MARC::File::* modules to read from a file.
new_from_usmarc( $marcblob [, \&filter_func($tagno,$tagdata)] )This is a wrapper around MARC::File::USMARC::decode() for compatibility with
older versions of MARC::Record.
The wanted_func() is optional. See the MARC::File::USMARC manpage::decode for details.
Following are a number of convenience methods for commonly-retrieved
data fields. Please note that they each return strings, not MARC::Field
objects. They return empty strings if the appropriate field or subfield
is not found. This is as opposed to the field()/subfield() methods
which return undef if something's not found. My assumption is that
these methods are used for quick & dirty reports and you don't want to
mess around with noting if something is undef.
Also note that no punctuation cleanup is done. If the 245a is ``Programming Perl / '', then that's what you'll get back, rather than ``Programming Perl''.
title()Returns the title from the 245 tag.
title_proper()Returns the title proper from the 245 tag, subfields a, n and p.
author()Returns the author from the 100, 110 or 111 tag.
edition()Returns the edition from the 250 tag, subfield a.
publication_date()Returns the publication date from the 260 tag, subfield c.
fields()Returns a list of all the fields in the record. The list contains a MARC::Field object for each field in the record.
field( tagspec(s) )Returns a list of tags that match the field specifier, or in scalar context, just the first matching tag.
The field specifier can be a simple number (i.e. ``245''), or use the ``.'' notation of wildcarding (i.e. subject tags are ``6..'').
subfield( $tag, $subfield )Shortcut method for getting just a subfield for a tag. These are equivalent:
my $title = $marc->field('245')->subfield("a");
my $title = $marc->subfield('245',"a");
If either the field or subfield can't be found, undef is returned.
append_fields( @fields )Appends the field specified by $field to the end of the record.
@fields need to be MARC::Field objects.
my $field = MARC::Field->new('590','','','a' => 'My local note.');
$record->append_fields($field);
Returns the number of fields appended.
insert_fields_before( $before_field, @new_fields )Inserts the field specified by $new_field before the field $before_field.
Returns the number of fields inserted, or undef on failures.
Both $before_field and all @new_fields need to be MARC::Field objects.
If they are not an exception will be thrown.
my $before_field = $record->field('260');
my $new_field = MARC::Field->new('250','','','a' => '2nd ed.');
$record->insert_fields_before($before_field,$new_field);
insert_fields_after( $after_field, @new_fields )Identical to insert_fields_before(), but fields are added after
$after_field. Remember, $after_field and any new fields must be
valid MARC::Field objects or else an exception will be thrown.
insert_fields_ordered( @new_fields )Will insert fields in strictly numerical order. So a 008 will be filed
after a 001 field. See insert_grouped_field() for an additional ordering.
insert_grouped_field( $field )Will insert the specified MARC::Field object into the record in grouped order and return true (1) on success, and false (undef) on failure.
my $field = MARC::Field->new( '510', 'Indexed by Google.' );
$record->insert_grouped_field( $field );
For example, if a '650' field is inserted with insert_grouped_field()
it will be inserted at the end of the 6XX group of tags. After discussion
most people wanted the ability to add a new field to the end of the
hundred group where it belonged. The reason is that according to the MARC
format, fields within a record are supposed to be grouped by block
(hundred groups). This means that fields may not necessarily be in tag
order.
delete_field( $field )Deletes a field from the record.
The field must have been retrieved from the record using the
field() method. For example, to delete a 526 tag if it exists:
my $tag526 = $marc->field( "526" );
if ( $tag526 ) {
$marc->delete_field( $tag526 );
}
delete_field() returns the number of fields that were deleted.
This shouldn't be 0 unless you didn't get the tag properly.
as_usmarc()This is a wrapper around MARC::File::USMARC::encode() for compatibility with
older versions of MARC::Record.
as_formatted()Returns a pretty string for printing in a MARC dump.
leader()Returns the leader for the record. Sets the leader if text is defined. No error checking is done on the validity of the leader.
set_leader_lengths( $reclen, $baseaddr )Internal function for updating the leader's length and base address.
clone()The clone() method makes a copy of an existing MARC record and returns
the new version. Note that you cannot just say:
my $newmarc = $oldmarc;
This just makes a copy of the reference, not a new object. You must use
the clone() method like so:
my $newmarc = $oldmarc->clone;
You can also specify field specs to filter down only a certain subset of fields. For instance, if you only wanted the title and ISBN tags from a record, you could do this:
my $small_marc = $marc->clone( 245, '020' );
The order of the fields is preserved as it was in the original record.
warnings()Returns the warnings (as a list) that were created when the record was read. These are things like ``Invalid indicators converted to blanks''.
my @warnings = $record->warnings();
The warnings are items that you might be interested in, or might not. It depends on how stringently you're checking data. If you're doing some grunt data analysis, you probably don't care.
A side effect of calling warnings() is that the warning buffer will
be cleared.
add_fields()add_fields() is now deprecated, and users are encouraged to use
append_fields(), insert_fields_after(), and insert_fields_before()
since they do what you want probably. It is still here though, for backwards
compatability.
add_fields() adds MARC::Field objects to the end of the list. Returns the
number of fields added, or undef if there was an error.
There are three ways of calling add_fields() to add data to the record.
my $author = MARC::Field->new(
100, "1", " ", a => "Arnosky, Jim."
);
$marc->add_fields( $author );
add_fields() take care of the objectifying.
$marc->add_fields(
245, "1", "0",
a => "Raccoons and ripe corn /",
c => "Jim Arnosky.",
);
$marc->add_fields(
[ 250, " ", " ", a => "1st ed." ],
[ 650, "1", " ", a => "Raccoons." ],
);
A brief discussion of why MARC::Record is done the way it is:
the MARC::Record manpage, the MARC::Lint manpage
my @sears_headings = $marc->tag_grep( /Sears/ );
(from Mike O'Regan)
for my $field ( $record->field( "856" ) ) {
$record->delete_field( $field ) unless useful($field);
} # for
(from Anne Highsmith hismith@tamu.edu)
Please feel free to email me at <andy@petdance.com>. I'm glad
to help as best I can, and I'm always interested in bugs, suggestions
and patches.
An excellent place to look for information, and get quick help, is from the perl4lib mailing list. See http://perl4lib.perl.org for more information about this list, and other helpful MARC information.
The MARC::Record development team uses the RT bug tracking system at
http://rt.cpan.org. If your email is about a bug or suggestion,
please report it through the RT system. This is a huge help for the
team, and you'll be notified of progress as things get fixed or updated.
If you prefer not to use the website, you can send your bug to <
<bug-MARC-Record@rt.cpan.org >>
Ideas are things that have been considered, but nobody's actually asked for.
This code may be distributed under the same terms as Perl itself.
Please note that these modules are not products of or supported by the employers of the various contributors to the code.
Andy Lester, <andy@petdance.com>