UFAL/Add CCMM 1.1.0 OAI-PMH crosswalk (ccmm-xml metadataPrefix)

[milanmajchrak]

Problem description

Add CCMM 1.1.0 OAI-PMH crosswalk

Implements export of metadata in CCMM (Czech Common Metadata Model) 1.1.0 format over OAI-PMH, as required for NMD/NRP compliance.

Changes:

• New XSL crosswalk (ccmm.xsl) mapping DSpace metadata to CCMM dataset XML (metadataPrefix: ccmm-xml)
• Registered in xoai.xml (Default Context + openaire_data Context)
• 14 unit tests + test data

Metadata mapping: title, identifiers (Handle/DOI), creators/contributors, publisher, publication year, dates, resource type, language, rights/license, subjects, descriptions, funding references, related resources, metadata identification with repository info.

Resolves: ufal#1145

Analysis

(Write here, if there is needed describe some specific problem. Erase it, when it is not needed.)

Problems

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Manual Testing (if applicable)

• Added to testing scenarios

Copilot review

• Requested review from Copilot

[Copilot]

Pull request overview

This PR implements a new OAI-PMH crosswalk for exporting DSpace metadata in CCMM (Czech Common Metadata Model) 1.1.0 format, required for NMD/NRP (National Repository of Gray Literature) compliance in the Czech Republic. The implementation follows the standard DSpace OAI-PMH crosswalk pattern used by other metadata formats in the repository.

Changes:

• New XSL transformation stylesheet mapping DSpace internal metadata to CCMM 1.1.0 XML schema
• Configuration updates to register the new crosswalk in both Default Context and openaire_data Context
• Comprehensive test suite with 14 unit tests and dedicated test data file

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 14 comments.

File	Description
dspace/config/crosswalks/oai/xoai.xml	Registers ccmm format (metadataPrefix: ccmm-xml) in Default and openaire_data contexts
dspace/config/crosswalks/oai/metadataFormats/ccmm.xsl	633-line XSLT 2.0 stylesheet implementing DSpace to CCMM metadata transformation with fallback handling for required fields
dspace-oai/src/test/java/org/dspace/xoai/tests/stylesheets/CcmmXslTest.java	Test class with 14 tests validating core CCMM elements (identifiers, creators, subjects, license, etc.)
dspace-oai/src/test/resources/xoai-ccmm-test.xml	Test fixture simulating typical NMD/NRP dataset metadata with Czech academic repository data

[Copilot]

The hardcoded string "http://unknown.repository" should be extracted as a constant or defined at the top of the stylesheet for better maintainability.

[Copilot]

The logic for extracting the repository base URL by finding '/handle/' in the URI and taking everything before it (lines 114-115) may not work correctly for all Handle server configurations. Some repositories might use different URL patterns (e.g., using a different path segment). Consider adding a comment explaining the assumptions about Handle URL structure, or making this more robust by also checking for 'hdl.handle.net' pattern.

[Copilot]

The test suite lacks coverage for the fallback scenarios where required fields are missing. Consider adding tests that verify the behavior when title, identifiers, publication year, time references, and subjects are missing to ensure fallback values (like "Untitled", "9999", etc.) are correctly produced. This is particularly important for required CCMM fields.

[Copilot]

Pull request overview

Copilot reviewed 5 out of 5 changed files in this pull request and generated 10 comments.

[Copilot]

The FormatDate template creates an empty ccmm:date element at line 660 when the date string is invalid. This produces invalid XML output like 'ccmm:date/' or 'ccmm:date</ccmm:date>' which may not validate against the CCMM schema. Consider either omitting the element entirely or providing a fallback value, or documenting that this is intentional if the schema permits empty date elements.

Suggested change

<ccmm:date/>

[Copilot]

The PrimaryLanguage template could be clearer by explicitly selecting only the first language value with '[1]' predicate. Currently, line 440 selects all dc.language.iso values, and XSLT's atomization implicitly uses the first one at line 446. While functionally correct, explicitly selecting '[1]' at line 440 would make the intent clearer and match the pattern used in OtherLanguages at line 468 where position() > 1 explicitly excludes the first.

[Copilot]

The original_repository IRI extraction logic may produce incorrect results when dc.identifier.uri contains non-Handle URIs. Lines 127-132 will output the full URI (e.g., a DOI URL) as the repository IRI if it doesn't contain '/handle/'. Consider filtering to only Handle URIs (checking for 'hdl.handle.net' or '/handle/'), or falling back to FALLBACK_REPOSITORY_URL for non-Handle URIs, similar to the Identifiers template logic at lines 152-153.

[Copilot]

The ResourceType template at line 418 selects all dc.type values into $dctype variable, but only the first value will be used (due to XSLT atomization in the when tests). If multiple dc.type values exist, subsequent values are silently ignored. For clarity, explicitly select only the first value with '[1]' predicate, similar to the pattern used elsewhere in the stylesheet.

[Copilot]

The FundingReferences template lacks error handling for malformed grant agreement URIs. If a dc.relation value starts with 'info:' but doesn't have the expected structure (e.g., fewer than 5 parts after tokenizing by '/'), the code attempts to access $parts[3] and potentially $parts[5], which could produce empty values or runtime errors. Consider adding validation to ensure the URI has the expected number of parts before accessing array indices.

Suggested change

	<ccmm:funding_reference>
	<xsl:if test="count($parts) >= 5">
	<ccmm:local_identifier><xsl:value-of select="$parts[5]"/></ccmm:local_identifier>
	</xsl:if>
	<ccmm:funder>
	<ccmm:organization>
	<ccmm:name>
	<xsl:choose>
	<xsl:when test="$parts[3]='EC'">European Commission</xsl:when>
	<xsl:otherwise><xsl:value-of select="$parts[3]"/></xsl:otherwise>
	</xsl:choose>
	</ccmm:name>
	</ccmm:organization>
	</ccmm:funder>
	</ccmm:funding_reference>
	<xsl:variable name="parts-count" select="count($parts)"/>
	<xsl:if test="$parts-count &gt;= 3">
	<ccmm:funding_reference>
	<xsl:if test="$parts-count &gt;= 5">
	<ccmm:local_identifier><xsl:value-of select="$parts[5]"/></ccmm:local_identifier>
	</xsl:if>
	<ccmm:funder>
	<ccmm:organization>
	<ccmm:name>
	<xsl:choose>
	<xsl:when test="$parts[3]='EC'">European Commission</xsl:when>
	<xsl:otherwise><xsl:value-of select="$parts[3]"/></xsl:otherwise>
	</xsl:choose>
	</ccmm:name>
	</ccmm:organization>
	</ccmm:funder>
	</ccmm:funding_reference>
	</xsl:if>

[Copilot]

The FundingReferences and RelatedResources templates lack test coverage. No tests verify the parsing of grant agreement URIs (info:eu-repo/grantAgreement format) or the handling of dc.relation.uri and dc.relation.ispartof fields. Add test cases with sample funding data and related resource data to ensure these mappings work correctly.

[Copilot]

The TermsOfUse template handles three access rights scenarios (embargoed, restricted, open), but only the default "open access" case is tested. Add test cases with local.embargo.termslift and others.restrictedAccess fields to verify embargoed and restricted access mappings produce correct COAR access rights IRIs.

[Copilot]

The FormatDate template handles multiple date format variations (datetime with T, full date YYYY-MM-DD, year-month YYYY-MM, year-only YYYY, and malformed dates), but there are no tests covering these different formats. Add tests to verify that dates in different formats are correctly transformed, especially edge cases like year-only or year-month dates that need padding with '-01' or '-01-01'.

[Copilot]

Inconsistent indentation for the Format element. The CCMM format definition uses 8-space indentation while the preceding ELG format uses 4-space indentation. For consistency with surrounding Format definitions (lines 217-235), use 4-space indentation for the Format element and 8-space indentation for its child elements.

Suggested change

	<Format id="ccmm">
	<Prefix>ccmm-xml</Prefix>
	<XSLT>metadataFormats/ccmm.xsl</XSLT>
	<Namespace>https://schema.ccmm.cz/research-data/1.1</Namespace>
	<SchemaLocation>https://techlib.github.io/CCMM/dataset/schema.xsd</SchemaLocation>
	</Format>
	<Format id="ccmm">
	<Prefix>ccmm-xml</Prefix>
	<XSLT>metadataFormats/ccmm.xsl</XSLT>
	<Namespace>https://schema.ccmm.cz/research-data/1.1</Namespace>
	<SchemaLocation>https://techlib.github.io/CCMM/dataset/schema.xsd</SchemaLocation>
	</Format>

[Copilot]

No test coverage for the time_reference element, which is a required CCMM field. The TimeReferences template handles multiple date types (Issued, Accepted, Available) and includes fallback logic, but none of these scenarios are tested. Add tests to verify that different date fields produce correct time_reference elements with appropriate date_type values and temporal_representation formatting.