@biblioteksentralen/marc

Package for representating MARC records in TypeScript and serialize to/from MARC XML and JSON.

The JSON serialization is compatible with the schema defined by https://www.npmjs.com/package/@natlibfi/marc-record

Usage

Parsing and serializing XML

import { parseMarcXml, serializeMarcXml } from "@biblioteksentralen/marc";

const xmlRecord = `
<record xmlns="http://www.loc.gov/MARC21/slim">
  <leader>00000cam^a22001937i^4500</leader>
  <controlfield tag="001">000030000</controlfield>
  <controlfield tag="003">FI-MELINDA</controlfield>
  <controlfield tag="005">20141221175522.0</controlfield>
  <controlfield tag="008">890208s1988^^^^sw^|||||||||||||||||swe||</controlfield>
  <datafield tag="020" ind1=" " ind2=" ">
    <subfield code="a">91-38-61844-3</subfield>
    <subfield code="q">inb.</subfield>
  </datafield>
  <datafield tag="100" ind1="0" ind2=" ">
    <subfield code="a">Durö, Robert.</subfield>
  </datafield>
  <datafield tag="245" ind1="1" ind2="0">
    <subfield code="a">Konkurrensöverlägsenhet :</subfield>
    <subfield code="b">i tio konkreta steg /</subfield>
    <subfield code="c">Robert Durö.</subfield>
  </datafield>
</record>
`;

const record = parseMarcXml(xmlRecord);
const title = record
  .getSubfieldValues("245", /a|b|n|p/)
  .join(" ")
  ?.trim();

const xml = serializeMarcXml(record);

Serializing Line MARC

import {
  createControlField,
  createDataField,
  createSubfield,
  serializeLineMarc
} from "@biblioteksentralen/marc";

const record = new MarcRecord({
  leader: "...",
  fields: [
    createControlField(...),
    createDataField(...),
  ]
});

const lineMarc = serializeLineMarc(record);

Serializing and deserializing as JSON

The MarcRecord class can be JSON serialized:

const serializedRecord = JSON.stringify(record);

and deserialized:

const record = MarcRecord.fromJSON(JSON.parse(serializedRecord));

Standalone fields can also be deserialized using the createDataField function – useful for tests:

const field = createDataField({
  tag: "020",
  subfields: [{ code: "a", value: "9788283982701" }],
});

Parsing MARC-in-JSON

YAZ and some Z39.50 stacks emit the MARC-in-JSON serialization (Ross Singer), which differs from the @natlibfi/marc-record JSON shape used by MarcRecord.fromJSON(). Use parseMarcInJson for that format:

import { parseMarcInJson } from "@biblioteksentralen/marc";

const record = parseMarcInJson({
  leader: "01678nam  2200409 i 4500",
  fields: [
    { "001": "BDZ0037757511" },
    {
      "245": {
        ind1: "1",
        ind2: "0",
        subfields: [{ a: "Robot rampage /" }, { c: "Steve Barlow." }],
      },
    },
  ],
});

JSON Schema validation

The package exports a JSON schema that can be used to validate JSON serialized MARC record structure using AJV or other JSON Schema validators.

import Ajv from "ajv";
import { createMarcSchema } from "@biblioteksentralen/marc";

const schema = createMarcSchema();
const ajv = new Ajv();
const validate = ajv.compile(schema);
const result = validate(record.toJSON());

Changelog

• 0.5.0: Add parseMarcInJson for the MARC-in-JSON (Ross Singer / YAZ) serialization.
• 0.4.0: Line MARC serialization: Remove linebreaks and trim surrounding whitespace. Make dollar escape character configurable.
• 0.3.0: Upgrade to Zod 4
• 0.2.0: Removed the logger argument from MarcRecord.fromJSON().