glam/frontend/STEP1_COMPLETE.md

Step 1 Complete: Oxigraph Setup ✅

Summary

Successfully set up Oxigraph triplestore in-memory mode with sample data and created SPARQL HTTP client.

Completed Tasks

1.1 Oxigraph Installation ✅

• Downloaded Oxigraph v0.5.2 binary
• Installed to ~/.local/bin/oxigraph_server
• Created installation script: scripts/install-oxigraph.sh

1.2 Server Scripts ✅

• scripts/start-oxigraph-memory.sh - Start in-memory server (no persistence)
• scripts/load-sample-data.sh - Load N-Triples data into default graph
• scripts/load-and-start.sh - Combined startup + data loading

Key Learning: Use PUT to /store?default to load data into default graph (not POST)

1.3 Sample RDF Data ✅

• Created data/sample-rdf/dutch-heritage-institutions.nt (78 triples)
• 6 Dutch heritage institutions:
  • Amsterdam Museum
  • Rijksmuseum
  • Koninklijke Bibliotheek (National Library)
  • Stadsarchief Amsterdam (City Archives)
  • Van Gogh Museum
  • Mauritshuis
• Schema.org vocabulary
• Multilingual labels (English + Dutch)
• Wikidata links via owl:sameAs

1.4 SPARQL HTTP Client ✅

• Created src/lib/sparql/client.ts (200 lines)

  • SparqlClient class with methods:
    • executeSelect() - SELECT queries
    • executeAsk() - ASK queries
    • executeConstruct() - CONSTRUCT/DESCRIBE queries
    • testConnection() - Health check
    • getTripleCount() - Database statistics
  • SparqlError exception class
  • Environment configuration via VITE_SPARQL_ENDPOINT
  • Timeout support (default 30s)
  • AbortController for cancellation

• Created tests/unit/sparql-client.test.ts (20 tests passing, 1 skipped)

  • Constructor tests (4)
  • executeSelect tests (5)
  • executeAsk tests (2)
  • executeConstruct tests (1)
  • testConnection tests (2)
  • getTripleCount tests (2)
  • Error handling tests (2)
  • Configuration tests (2)

1.5 Environment Configuration ✅

• Created .env.local:

  VITE_SPARQL_ENDPOINT=http://localhost:7878/query
  

Technical Notes

Oxigraph ARM Issue (Documented)

• Persistent storage crashes on macOS ARM (RocksDB bug)
• Solution: Use in-memory mode for development
• Trade-off: Data reloads on restart (~1 second)
• Alternative: Docker container (Linux environment)

Data Loading Method

# WRONG (creates named graph)
curl -X POST -H 'Content-Type: application/n-triples' \
  --data-binary '@data.nt' http://localhost:7878/store

# CORRECT (loads into default graph)
curl -X PUT -H 'Content-Type: application/n-triples' \
  --data-binary '@data.nt' http://localhost:7878/store?default

SPARQL Endpoint URLs

• Query endpoint: http://localhost:7878/query (SELECT, ASK, CONSTRUCT, DESCRIBE)
• Store endpoint: http://localhost:7878/store (data loading)
• Health check: http://localhost:7878/ (returns 200)

Test Results

Before: 148 tests passing
After: 168 tests passing (+20)
Status: ✅ All passing (1 skipped)

Files Created/Modified

frontend/
├── .env.local                          ✅ Created
├── scripts/
│   ├── install-oxigraph.sh             ✅ Created
│   ├── start-oxigraph-memory.sh        ✅ Created
│   ├── load-sample-data.sh             ✅ Modified (PUT method)
│   └── load-and-start.sh               ✅ Created
├── data/
│   └── sample-rdf/
│       └── dutch-heritage-institutions.nt  ✅ Created (comments removed)
├── src/lib/sparql/
│   └── client.ts                       ✅ Created (200 lines)
├── tests/unit/
│   └── sparql-client.test.ts           ✅ Created (21 tests)
├── OXIGRAPH_STATUS.md                  📝 Reference doc
└── PHASE3_TASK7_PLAN.md                📝 Plan doc

Verification

Server Status

$ curl -s http://localhost:7878/ && echo "✅ Server running"

Data Verification

$ curl -X POST \
  -H 'Content-Type: application/sparql-query' \
  -H 'Accept: application/sparql-results+json' \
  --data 'SELECT (COUNT(*) as ?count) WHERE { ?s ?p ?o }' \
  http://localhost:7878/query | jq '.results.bindings[0].count.value'

# Expected output: "78"

Query Example

$ curl -X POST \
  -H 'Content-Type: application/sparql-query' \
  -H 'Accept: application/sparql-results+json' \
  --data 'SELECT ?museum ?name WHERE { 
    ?museum a <http://schema.org/Museum> ; 
            <http://schema.org/name> ?name 
  } LIMIT 5' \
  http://localhost:7878/query | jq

Next Steps

✅ Step 1 Complete - Oxigraph + SPARQL Client
⏳ Step 2 Next - Results Table Component (2.5 hours)

Continue with:

1. Create src/components/query/ResultsTable.tsx
2. Create src/components/query/ResultsTable.css
3. Features:
   • Display SPARQL SELECT results in table
   • Column sorting
   • Pagination (100 rows/page)
   • URI rendering (clickable links)
   • Cell type styling (URI, literal, bnode)
4. Tests: tests/unit/results-table.test.tsx (~12-15 tests)

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Status: ✅ COMPLETE
Duration: ~1.5 hours (as estimated)
Test Coverage: +20 tests (168 total)
Lines of Code: ~400 (client + tests)