NAME

PICA::Data - PICA record processing

SYNOPSIS

  use PICA::Data ':all';
  $parser = pica_parser( xml => 'picadata.xml' );
  $writer = pica_writer( plain => \*STDOUT );
 
  use PICA::Parser::XML;
  use PICA::Writer::Plain;
  $parser = PICA::Parser::XML->new( @options );
  $writer = PICA::Writer::Plain->new( @options );

  use PICA::Schema;
  $schema = PICA::Schema->new();

  # parse records
  while ( my $record = $parser->next ) {
      
      # function accessors
      my $ppn      = pica_value($record, '003@0');
      my $ppn      = pica_match($record, '045Ue', split => 1, nested_array => 1);
      my $holdings = pica_holdings($record);
      my $items    = pica_items($record);
      ...

      # object accessors (if parser option 'bless' enabled)
      my $ppn      = $record->{_id};
      my $ppn      = $record->value('003@0');
      my $ddc      = $record->match('045Ue', split => 1, nested_array => 1);
      my $holdings = $record->holdings;
      my $items    = $record->items;
      ...

      # write record
      $writer->write($record);
      
      # write record via method (if blessed)
      $record->write($writer);
      $record->write( xml => @options );
      $record->write; # default "plain" writer

      # stringify record
      my $plain = $record->string;
      my $xml = $record->string('xml');

      # validate record
      my $errors = $schema->check($record);
  }

  # parse single record from string
  my $record = pica_parser('plain', \"...")->next;

  # guess parser from input string
  my $parser = pica_guess($string)->new(\$string);

DESCRIPTION

PICA::Data provides methods, classes, functions, and picadata to process PICA+ records in Perl.

PICA+ is the internal data format of the Local Library System (LBS) and the Central Library System (CBS) of OCLC, formerly PICA. Similar library formats are the MAchine Readable Cataloging format (MARC) and the Maschinelles Austauschformat fuer Bibliotheken (MAB). In addition to PICA+ in CBS there is the cataloging format Pica3 which can losslessly be convert to PICA+ and vice versa.

Records in PICA::Data are encoded either as array of arrays, the inner arrays representing PICA fields, or as an object with two keys, _id and record, the latter holding the record as array of arrays, and the former holding the record identifier, stored in field 003@, subfield 0. For instance a minimal record with just one field (having tag 003@ and no occurrence):

{
  _id    => '12345X',
  record => [
    [ '003@', undef, '0' => '12345X' ]
  ]
}

or in short form:

[ [ '003@', undef, '0' => '12345X' ] ]

PICA path expressions (see PICA::Path) can be used to facilitate processing PICA+ records and PICA::Schema can be used to validate PICA+ records with Avram Schemas.

FUNCTIONS

The following functions can be exported on request (use export tag :all to get all of them):

pica_parser( $type [, @options] )

Create a PICA parsers object (see PICA::Parser::Base). Case of the type is ignored and additional parameters are passed to the parser's constructor:

• PICA::Parser::Binary for type binary (binary PICA+)
• PICA::Parser::Plain for type plain or picaplain (human-readable PICA+)
• PICA::Parser::Plus for type plus or picaplus (normalized PICA+)
• PICA::Parser::JSON for type json (PICA JSON)
• PICA::Parser::XML for type xml or picaxml (PICA-XML)
• PICA::Parser::PPXML for type ppxml (PicaPlus-XML)

pica_guess( $data )

Guess PICA serialization format from input data. Returns name of the corresponding parser class or undef.

pica_xml_struct( $xml, %options )

Convert PICA-XML, expressed in XML::Struct structure into an (optionally blessed) PICA record structure.

pica_writer( $type [, @options] )

Create a PICA writer object (see PICA::Writer::Base) in the same way as pica_parser with one of

• PICA::Writer::Binary for type binary (binary PICA)
• PICA::Writer::Generic for type generic (PICA with self defined data separators)
• PICA::Writer::Plain for type plain or picaplain (human-readable PICA+)
• PICA::Writer::Plus for type plus or picaplus (normalized PICA+)
• PICA::Writer::JSON for type json (PICA JSON)
• PICA::Writer::XML for type xml or picaxml (PICA-XML)
• PICA::Writer::PPXML for type ppxml (PicaPlus-XML)

pica_path( $path )

Equivalent to PICA::Path->new($path).

pica_match( $record, $path, %options )

Equivalent to PICA::Path->match_record($path, %options).

Extract the subfield values from a PICA record based on a PICA path expression and options (see PICA::Path). Also available as accessor match($path, %options).

pica_value( $record, $path )

Extract the first subfield values from a PICA record based on a PICA path expression. Also available as accessor value($path).

pica_values( $record, $path )

Extract a list of subfield values from a PICA record based on a PICA path expression. The following are virtually equivalent:

pica_values($record, $path);
$path->record_subfields($record);
$record->values($path); # if $record is blessed

pica_fields( $record, $path[, $path...] )

Returns a PICA record (or empty array reference) limited to fields specified inione ore more PICA path expression. The following are virtually equivalent:

pica_fields($record, $path);
$path->record_fields($record);
$record->fields($path); # if $record is blessed

pica_holdings( $record )

Returns a list (as array reference) of local holding records. Also available as accessor holdings.

pica_items( $record )

Returns a list (as array reference) of item records. Also available as accessor items.

ACCESSORS

All accessors of PICA::Data are also available as "FUNCTIONS", prefixed with pica_ (see "SYNOPSIS").

match( $path, %options )

Extract a list of subfield values from a PICA record based on a PICA::Path expression and options.

values( $path )

Extract a list of subfield values from a PICA record based on a PICA::Path expression.

value( $path )

Same as values but only returns the first value.

fields( $path[, $path...] )

Returns a PICA record limited to fields specified in a PICA::Path expression. Always returns an array reference.

holdings

Returns a list (as array reference) of local holding records (level 1 and 2), where the _id of each record contains the ILN (subfield 101@a).

items

Returns a list (as array reference) of item records (level 1), where the _id of each record contains the EPN (subfield 203@/**0).

METHODS

write( [ $type [, @options] ] | $writer )

Write PICA record with given PICA::Writer::Base or PICA::Writer::Plain by default. This method is a shortcut for blessed record objects:

pica_writer( xml => $file )->write( $record );
$record->write( xml => $file ); # equivalent if $record is blessed 

string( [ $type ] )

Serialize PICA record in a given format (plain by default).

CONTRIBUTORS

Johann Rolschewski, <[email protected]>

Jakob Voß <[email protected]>

Carsten Klee <[email protected]>

COPYRIGHT AND LICENSE

Copyright 2014- Johann Rolschewski and Jakob Voss

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

SEE ALSO

• picadata command line script to parse, serialize, count, and validate PICA+ data.
• Use Catmandu::PICA for more elaborated processing of PICA records with the Catmandu toolkit.
• PICA::Record implemented an alternative framework for processing PICA+ records (deprecated!).