Galen Charlton
and 1 contributors


MARC::Record::MiJ - Convert MARC::Record to/from marc-in-json structure


Version 0.04


  use MARC::Record;
  use MARC::Record::MIJ

  my $str = get_marc_in_json_from_somewhere;

  # The most common use will be to use methods monkeypatched into MARC::Record
  my $r = MARC::Record->new_from_mij($str);
  my $json = $r->to_mij;

  # You can also work with the underlying hash/array structure if you're dealing with
  # json serialization/deserialization on your own

  my $mij_structure = $r->to_mij_structure;
  my $r = MARC::Record->new_from_mij_structure($mij_structure);

  # You can also call things on MARC::Record::MiJ

  my $r = MARC::Record::MiJ->new($str);
  my $json = MARC::Record::MiJ->to_mij($r);
  my $mij_structure = MARC::Record::MiJ->to_mij_structure($r);
  my $r = MARC::Record::MiJ->new_from_mij_structure($mij_structure);


Reads and writes MARC-in-JSON structures and strings as supported by pymarc/ruby-marc/marc4j and described at

Don't confuse with another (incompatible) JSON encoding in the module MARC::File::JSON, which to the best of my knowledge isn't supported by other readers/writers.

For reading, you probably don't need to use this directly; take a look at MARC::File::MiJ for reading in newline-delimited marc-in-json files by itself or in conjunction with MARC::Batch.

The MARC::Record distribution doesn't so much do do writing out files. You can do something like this:

    # convert file from marc binary to marc-in-json
    use MARC::Batch;
    use MARC::Record::MiJ;
    my $batch = MARC::Batch->new('USMARC', 'file.mrc');
    open(my $jsonfile, '>', 'file.ndj' );
    while (my $r = $batch->next) {
      print $jsonfile MARC::Record::MiJ->to_mij($r), "\n";
    close $jsonfile; produce newline-delimited marc-in-json from a binary file.



Get a json object to work with (memoized). We want to control it so we make sure it's not doing anything pretty (like, say, putting newlines in, which woudl make it harder to produce newline-delimited json file).


Take a JSON string and turn it into a MARC::Record object


Take a record; return a JSON string


Turn a record into a marc-in-json compatible hash; return the hash pointer


Turn a MARC::Record controlfield into an appropriate hash


Turn a MARC::Record valuefield into an appropriate hash


Turn a MARC::Record subfield pair (arrayref duple of code/value) into an appropriate hash

my $r = MARC::Record::JSON->new_from_mij_structure($mij_structure)

Given a marc-in-json structure, return a MARC::Record object


Given a field structure, create an appropriate (control or variable) field


Support for new_field_from_mij_structure; do the more complex work of creating a datafield

Monkeypatching MARC::Record

Add new_from_mij_structure($mij_structure) and to_mij_structure() to MARC::Record

  my $r = MARC::Record->new_from_mij_structure($mij_structure);
  $mij_structure = $r->to_mij_structure;


Bill Dueber, <dueberb at>


Please report any bugs or feature requests to bug-MARC-File-MiJ at, or through the web interface at I will be notified, and then you'll automatically be notified of progress on your bug as I make changes.


You can find documentation for this module with the perldoc command.

    perldoc MARC::Record::MiJ

You can also look for information at:



Copyright 2013 Bill Dueber.

This software is free software and may be distributed under the same terms as Perl itself.

1 POD Error

The following errors were encountered while parsing the POD:

Around line 252:

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