Interoperability - Dzaleka Metadata Standard

DMS is designed to work with existing archival and semantic web standards. Every field maps to a recognised vocabulary, and three machine-readable schema formats make it possible to consume DMS records with standard tooling in any language or platform.

DMS is fully compatible with Dublin Core — the most widely used metadata standard for digital heritage and library resources. Every DMS field maps directly to a Dublin Core element or term, allowing DMS records to be harvested, indexed, and exchanged by any system that understands Dublin Core.

Dublin Core field mapping

All 15 DMS fields map to a dc: or dcterms: property. Fields with no equivalent Dublin Core term use a dms: or schema: extension property.

DMS field	Dublin Core / extension mapping	Namespace
`id`	`dc:identifier`	Dublin Core Elements
`title`	`dc:title`	Dublin Core Elements
`type`	`dc:type`	Dublin Core Elements
`description`	`dc:description`	Dublin Core Elements
`language`	`dc:language`	Dublin Core Elements
`creator`	`dc:creator`	Dublin Core Elements
`date`	`dc:date`	Dublin Core Elements
`date.created`	`dcterms:created`	Dublin Core Terms
`date.modified`	`dcterms:modified`	Dublin Core Terms
`date.event_date`	`dcterms:date`	Dublin Core Terms
`subject`	`dc:subject`	Dublin Core Elements
`location`	`dcterms:spatial`	Dublin Core Terms
`location.latitude`	`geo:lat`	W3C Geo
`location.longitude`	`geo:long`	W3C Geo
`location.area`	`dms:campArea`	DMS extension
`rights`	`dc:rights`	Dublin Core Elements
`rights.license`	`dcterms:license`	Dublin Core Terms
`rights.holder`	`dcterms:rightsHolder`	Dublin Core Terms
`rights.access_level`	`dms:accessLevel`	DMS extension
`source`	`dc:source`	Dublin Core Elements
`source.contributor`	`dcterms:contributor`	Dublin Core Terms
`source.collection`	`bibo:Collection`	BIBO
`source.original_format`	`dms:originalFormat`	DMS extension
`format`	`dc:format`	Dublin Core Elements
`relation`	`dc:relation`	Dublin Core Elements
`coverage`	`dc:coverage`	Dublin Core Elements
`coverage.start_date`	`schema:startDate`	Schema.org
`coverage.end_date`	`schema:endDate`	Schema.org
`coverage.period`	`dcterms:temporal`	Dublin Core Terms
`schema_version`	`schema:schemaVersion`	Schema.org

Vocabulary mappings

The dms.jsonld context declares prefix mappings for six external vocabularies. These mappings enable DMS records to be published as Linked Data and consumed by RDF-aware systems.

Vocabulary	Prefix	URI	Used for
Dublin Core	`dc:`, `dcterms:`	`http://purl.org/dc/elements/1.1/`, `http://purl.org/dc/terms/`	Core metadata fields: title, creator, subject, rights, etc.
FOAF	`foaf:`	`http://xmlns.com/foaf/0.1/`	Person and agent descriptions (`foaf:name`, `foaf:Person`, `foaf:Image`)
BIBO	`bibo:`	`http://purl.org/ontology/bibo/`	Bibliographic roles (`bibo:editor`, `bibo:translator`, `bibo:interviewer`)
Schema.org	`schema:`	`https://schema.org/`	Creative works, places, events, and affiliations
W3C Geo	`geo:`	`http://www.w3.org/2003/01/geo/wgs84_pos#`	Geographic coordinates (`geo:lat`, `geo:long`)
SKOS	`skos:`	`http://www.w3.org/2004/02/skos/core#`	Subject vocabularies and concept schemes

JSON-LD context

The file schema/dms.jsonld provides a JSON-LD 1.1 context that transforms any DMS JSON record into a valid RDF document. Loading the context alongside a record expands each field key into a fully qualified URI.

Context prefix declarations

schema/dms.jsonld (prefixes)

{
  "@context": {
    "@version": 1.1,
    "dms": "https://github.com/Dzaleka-Connect/Dzaleka-Metadata-Standard/schema#",
    "dc": "http://purl.org/dc/elements/1.1/",
    "dcterms": "http://purl.org/dc/terms/",
    "schema": "https://schema.org/",
    "foaf": "http://xmlns.com/foaf/0.1/",
    "bibo": "http://purl.org/ontology/bibo/",
    "xsd": "http://www.w3.org/2001/XMLSchema#",
    "geo": "http://www.w3.org/2003/01/geo/wgs84_pos#",
    "skos": "http://www.w3.org/2004/02/skos/core#"
  }
}

Type mappings in JSON-LD

Each value of the type enum is mapped to one or more Schema.org, FOAF, and BIBO classes in the @graph section of dms.jsonld.

`type` value	Primary class	Additional classes
`story`	`schema:Article`	`foaf:Document`, `bibo:Document`
`photo`	`schema:Photograph`	`foaf:Image`
`document`	`schema:DigitalDocument`	`foaf:Document`, `bibo:Document`
`audio`	`schema:AudioObject`	`bibo:AudioDocument`
`video`	`schema:VideoObject`	`bibo:AudioVisualDocument`
`event`	`schema:Event`	`bibo:Event`
`map`	`schema:Map`	`foaf:Document`
`artwork`	`schema:VisualArtwork`	`foaf:Image`
`site`	`schema:Place`	`schema:LandmarksOrHistoricalBuildings`
`poem`	`schema:CreativeWork`	`bibo:Document`

Example: record as JSON-LD

The following shows examples/story.json as it would be interpreted when expanded with the DMS JSON-LD context. Field keys resolve to their full URI equivalents.

story-as-jsonld.json

{
  "@context": "https://github.com/Dzaleka-Connect/Dzaleka-Metadata-Standard/schema/dms.jsonld",
  "@type": "dms:HeritageRecord",
  "dc:identifier": "b3e7c8a1-4d5f-6e7a-8b9c-0d1e2f3a4b5c",
  "dc:title": "Journey to Dzaleka: A Story of Hope",
  "dc:type": "story",
  "dc:description": "An oral history account of a Congolese family's journey from Bukavu to Dzaleka Refugee Camp in 2015.",
  "dc:language": "en",
  "dc:creator": [
    {
      "foaf:name": "Marie Consolée",
      "dms:creatorRole": "narrator"
    },
    {
      "foaf:name": "Jean-Baptiste Mushimiyimana",
      "dms:creatorRole": "interviewer",
      "schema:affiliation": "Dzaleka Digital Heritage Project"
    }
  ],
  "dc:date": {
    "dcterms:created": "2024-03-15",
    "dcterms:date": "2015-08-22"
  },
  "dc:subject": ["oral history", "displacement", "Congo", "journey", "resilience"],
  "dcterms:spatial": {
    "foaf:name": "Dzaleka Refugee Camp",
    "dms:campArea": "Community Center",
    "geo:lat": -13.7833,
    "geo:long": 33.9833
  },
  "dc:rights": {
    "dcterms:license": "CC-BY-NC-4.0",
    "dms:accessLevel": "public",
    "dcterms:rightsHolder": "Marie Consolée"
  },
  "dc:source": {
    "dcterms:contributor": "Dzaleka Digital Heritage Project",
    "bibo:Collection": "Oral Histories 2024",
    "dms:originalFormat": "audio interview (transcribed)"
  },
  "dc:coverage": {
    "schema:startDate": "2015-01-01",
    "schema:endDate": "2015-12-31",
    "dcterms:temporal": "2015 displacement and arrival"
  },
  "schema:schemaVersion": "1.0.0"
}

To export a DMS record as JSON-LD using the CLI:

dms export examples/story.json

CSV format

DMS supports importing and exporting records in CSV format for spreadsheet-based workflows. The CSV format uses the same field names as the JSON schema, with nested objects represented as flattened dot-notation columns.

CSV to JSON
JSON to CSV

Convert a CSV batch file to individual JSON records:

dms convert csv2json examples/batch.csv

Each row in the CSV becomes a separate JSON record file. Nested fields such as location.name, rights.license, and creator.0.name are expanded into their corresponding object structures.

Export a JSON record (single object or array) to CSV:

dms convert json2csv records/story_b3e7c8a1.json --output export.csv

Nested fields are flattened to _-separated column names. Multi-value fields such as subject and creator are serialised as pipe-separated values.

JSON Schema validation

The schema/dms.json file is a valid JSON Schema Draft 2020-12 document. Any JSON Schema validator can use it to validate DMS records in any language or platform.

dms validate examples/story.json

import json
import jsonschema

with open("schema/dms.json") as f:
    schema = json.load(f)

with open("examples/story.json") as f:
    record = json.load(f)

jsonschema.validate(instance=record, schema=schema)
print("Record is valid.")

import Ajv from "ajv";
import addFormats from "ajv-formats";
import schema from "./schema/dms.json" assert { type: "json" };
import record from "./examples/story.json" assert { type: "json" };

const ajv = new Ajv();
addFormats(ajv);

const validate = ajv.compile(schema);
const valid = validate(record);
console.log(valid ? "Record is valid." : validate.errors);

The dms validate command supports single files and entire directories. Use dms validate --dir records/ to validate all JSON files in a collection at once.

​Dublin Core field mapping

​Vocabulary mappings

​JSON-LD context

​Context prefix declarations

​Type mappings in JSON-LD

​Example: record as JSON-LD

​CSV format

​JSON Schema validation

Dublin Core field mapping

Vocabulary mappings

JSON-LD context

Context prefix declarations

Type mappings in JSON-LD

Example: record as JSON-LD

CSV format

JSON Schema validation