README

isy-thl/european-learning-model is a framework-independent PHP package for building European Learning Model (ELM) documents and deterministic unsigned JSON-LD. It currently focuses on European Digital Credentials (EDC), with shared ELM entities and incremental Learning Opportunities and Qualifications (LOQ) support.

The package produces document bytes. An application owns persistence, QDR delivery, HTTP, logging, and signing.

Current scope

The package currently provides:

shared ELM values and graph entities under Core;
EDC credentials, subjects, claims, displays, issuers, and profile validation under Edc;
LOQ qualifications, learning opportunities, references, document roots, and profile preflight validation under Loq;
controlled concepts, localized values, identifiers, dates, and vocabulary provider contracts; and
deterministic JSON-LD serialization with typed validation failures.

The package does not provide:

Framework specific adapters or database integration.
QDR HTTP clients, upload, hosting, API keys, or publication workflows;
DSS, CSC, JAdES, certificates, private keys, signatures, or proofs; or
a verified LOQ XML serializer.

EDC output is unsigned JSON-LD suitable for an application to pass unchanged to a separate signing boundary such as isy-thl/dss-csc-signing.

Requirements

PHP 8.1 or newer
PHP mbstring extension
Composer

Development and vocabulary-provider tests may also require PHP DOM/XML extensions.

Installation

composer require isy-thl/european-learning-model

The package namespace is IsyThl\EuropeanLearningModel.

Build an EDC credential

The main output is deterministic unsigned JSON-LD. Required child objects are constructed explicitly, and Credential::toJson() performs document validation before returning bytes.

use DateTimeImmutable;
use IsyThl\EuropeanLearningModel\Core\Concept;
use IsyThl\EuropeanLearningModel\Core\ConceptScheme;
use IsyThl\EuropeanLearningModel\Core\ElmVocabularySchemes;
use IsyThl\EuropeanLearningModel\Core\LocalizedString;
use IsyThl\EuropeanLearningModel\Edc\Claim;
use IsyThl\EuropeanLearningModel\Edc\Credential;
use IsyThl\EuropeanLearningModel\Edc\CredentialSubject;
use IsyThl\EuropeanLearningModel\Edc\DisplayParameter;

$english = new Concept(
	'http://publications.europa.eu/resource/authority/language/ENG',
	new LocalizedString(['en' => 'English']),
	new ConceptScheme(ElmVocabularySchemes::LANGUAGE),
	'ENG',
);

$subject = new CredentialSubject(
	'subject-1',
	new LocalizedString(['en' => 'Ada']),
	new LocalizedString(['en' => 'Lovelace']),
	new LocalizedString(['en' => 'Ada Lovelace']),
	[new class ('claim-1') extends Claim {
		public function toArray(): array {
			return ['id' => $this->id, 'type' => 'Claim'];
		}
	}],
);

$credential = new Credential(
	'credential-1',
	$subject,
	new DisplayParameter(
		'display-1',
		$english,
		$english,
		new LocalizedString(['en' => 'European Digital Credential']),
	),
	new DateTimeImmutable('2026-01-01T00:00:00+00:00'),
);

$unsignedJsonLd = $credential->toJson();

Equivalent object state produces byte-for-byte identical output. Dates are normalized to UTC and emitted as Y-m-d\TH:i:s\Z; unset optional fields are omitted. JSON encoding uses explicit flags and JSON_THROW_ON_ERROR.

Profiles and validation

EDC and LOQ validation are separate profile concerns:

EdcProfile::GENERIC_NO_CV and EdcProfile::GENERIC_FULL identify the supported EDC profiles and their bundled RDF resources.
EdcDocumentValidator checks the EDC document root and selected profile.
LoqProfileValidator checks LOQ-specific identifiers, publisher metadata, default language, learning outcomes, EQF, NQF, and ISCED-F requirements.
LoqDocumentValidator validates LOQ document aggregates before serialization.

The PHP validators are preflight checks. Standards-based RDF/JSON-LD/SHACL execution remains an injectable boundary; the package does not claim full SHACL conformance from the PHP checks alone.

Profile resources are bundled under resources/profile/ and are loaded by explicit local resource boundaries. Constructors, validators, and serializers do not retrieve profiles or vocabularies from the network.

LOQ documents

LOQ documents serialize to deterministic unsigned JSON-LD:

use IsyThl\EuropeanLearningModel\Loq\LoqDatasetDocument;
use IsyThl\EuropeanLearningModel\Loq\QualificationReference;

$reference = new QualificationReference($identifier, $datasetNamespace);
$dataset = new LoqDatasetDocument([$qualification, $learningOpportunity]);
$unsignedJsonLd = $dataset->toJson();

The model distinguishes an embedded Core\Qualification from an external QualificationReference. References require persistent identifiers and keep their dataset namespace as validated application metadata.

LOQ XML status

XML export is not yet implemented.

Controlled vocabularies

For small, trusted vocabularies, use InMemoryVocabularyProvider and a VocabularyScheme. For injected RDF or JSON resources, use RdfVocabularyProvider or JsonLdVocabularyProvider with an application-owned VocabularyResourceFetcher. For large schemes, use the bounded search providers under Vocabulary, including the ESCO search provider.

Vocabulary access is explicit and injectable. The package does not own HTTP credentials, endpoints, caching policy, or live retrieval from constructors. See the working examples:

examples/vocabulary-selection.php
examples/vocabulary-providers.php
examples/esco-search.php

Development and testing

composer install
composer test
composer analyse
composer style
composer lint
composer validate --strict
git diff --check

The test suite is plain PHP and does not require Moodle, QDR, DSS, CSC, or network services. Optional live vocabulary qualification requires network access and can be run separately:

ELM_LIVE_VOCABULARY_TESTS=1 vendor/bin/phpunit tests/LiveVocabularyTest.php

License

GPL-3.0-or-later

isy-thl / european-learning-model

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