/ 
PICA-Data-2.06
River stage one • 1 direct dependent • 1 total dependent
/ PICA::Data

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
      my $ppn      = $record->id;
      my $ppn      = $record->value('003@0');
      my $ppn      = $record->subfields('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 methods
      $record->write($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 a command line application to process PICA+ records.

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_data( [ $data ] )

Return a new PICA::Data object from any guessable serialization form (or die).

pica_field( $tag, [$occ,] [ @subfields ] )

Return a new PICA+ field as blessed PICA::Data::Field array reference (or die).

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_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 a PICA::Data object.

pica_writer( $type [, @options] )

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

pica_string( $record [, $type [, @options] ] )

Stringify a record with given writer (plain as default) and options.

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);

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

Returns a PICA record (or empty array reference) limited to fields optionally specified by PICA path expressions. The following are virtually equivalent:

pica_fields($record, $path);
$path->record_fields($record);
$record->fields($path);

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

Returns a Hash::MultiValue of all subfields of fields optionally specified by PICA path expressions. Also available as accessor subfields.

pica_title( $record )

Returns the record limited to level 0 fields ("title record") in sorted order.

pica_holdings( $record )

Returns a list (as array reference) of local holding records, sorted by ILN. Level2 fields are included in sorted order. The ILN (if given) is available as _id. Also available as accessor holdings.

pica_items( $record )

Returns a list (as array reference) of item records. The EPN (if given) is available as _id Also available as accessor items.

pica_split( $record [, $level ])

Returns the record splitted into individual records for each level. Optionally limits result to given level, including identifiers (PPN/ILN) of higher levels.

pica_sort( $record )

Returns a copy of the record with sorted fields (first level 1 fields, then level 2 fields not belonging to a level 1, then level 1, each followed by level 2 sorted by EPN). Also available as accessor sort.

pica_sort_subfields( $field, $schedule )

Sorts and filters subfields of a PICA field (given as array reference) with an subfield schedule. The schedule can also be given as string of subfield codes, parsed with parse_subfield_schedule: repeatable subfields must be marked with * or +, otherwise or only the first subfield of this code is preserved. Undefined and missing subfields are ignored as well as subfield without information about its order. Returns the modified field, unless it is empty.

pica_annotation( $field [, $annotation ] )

Get or set a PICA field annotation. Use undef to remove annotation.

pica_diff( $before, $after )

Return the difference between two records as annotated record. Also available as method diff. See PICA::Patch for details.

pica_patch( $record, $diff )

Return a new record by application of a difference given as annotated PICA. Also available as method patch. See PICA::Patch for details.

pica_append( $record, $tag, [$occurrence,] @subfields )

Append a new field to the end of the record.

pica_update( $record, ... )

Change an existing field. This method can be used like method append or with two arguments (path and value) to replace, add or remove a subfield value.

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

Remove all fields matching given PICA Path expressions. Subfields and positions in the path are ignored.

ACCESSORS

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

match( $path, %options )

Extract the subfield values from a PICA record based on a PICA::Path expression and options (see method match of PICA::Path).

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...] )

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

subfields( [$path...] )

Returns a Hash::MultiValue of all subfields of fields optionally specified by PICA path expressions.

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).

id

Returns the record id, if given.

empty

Tell whether the record is empty (no fields).

METHODS

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

Write PICA record with given PICA::Writer::... or PICA::Writer::Plain by default. This are equivalent:

pica_writer( xml => $file )->write( $record );
$record->write( xml => $file );

string( [ $type ] )

Serialize PICA record in a given format (plain by default). This method can also be used as function pica_string.

append( $tag, [$occurrence,] @subfields )

Add a field to the end of the record. An occurrence can be specified as part of the tag or as second argument. Subfields with empty value are ignored, so the following are equivalent:

$record->append('037A/01', a => 'hello', b => 'world', x => undef, y => '');
$record->append('037A', 1, a => 'hello', b => 'world');

To simplify migration from PICA::Record the field may also be given as instance of PICA::Field but this feature may be removed in a future version.

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

Remove all fields matching given PICA Path expressions. Subfields and positions are ignored.

update( ... )

Can be used like method append but replaces an existing field. Alternatively changes selected subfields if called with two arguments:

$record->update('012X$a', 1); # set or add subfield $a to 1, keep other subfields

Setting a subfield value to the empty string or undef removes the subfield.

diff( $record )

Calculate the difference of the record to another record.

patch( $diff )

Calculate a new record by application of an annotated PICA record. Annotations + and - denote fields to be added or removed. Fields with blank annotations are check to exist in the original record.

The records should not contain multiple records of level 1 and/or level 2.

CONTRIBUTORS

Johann Rolschewski, <jorol@cpan.org>

Jakob Voß <voss@gbv.de>

Carsten Klee <klee@cpan.org>

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!).