Improve getDistribution query #68

src/sparql/distribution.ts

@@ -14,6 +14,7 @@ import {
   executeSparqlConstruct
 } from './sparql'
 import { resourceContext } from './resource'
+import { ContextDefinition } from 'jsonld'
 
 export async function insertDistribution(
   distribution: Partial<OcDistribution>,
@@ -124,104 +125,74 @@ export async function getDistribution(
   identifier: string,
   auth?: Credentials
 ): Promise<OcDistribution> {
-  /**
-   * First, get the @id of the catalog
-   * to better filtering requests.
-   */
-  const distributionIdResponse = await executeSparqlConstruct<OcDistribution>(
-    `
-    CONSTRUCT {
-      ?distribution ?p ?o.
-      ?distribution oct:graph ?g.
-    }
-    WHERE {
-      ?distribution ?p ?o;
-        a dcat:Distribution.
 
-      GRAPH ?g {
-        ?distribution dct:identifier ?identifier.
-      }
-      FILTER (str(?identifier) = "${identifier}").
+  const context: ContextDefinition = {
+    ...resourceContext,
+    accessURL: { '@id': 'http://www.w3.org/ns/dcat#accessURL', '@type': '@id' },
+    license: { '@id': 'http://purl.org/dc/terms/license', '@type': '@id' },
+    type: { '@id': 'http://purl.org/dc/terms/type', '@type': '@id' },
+    accessRights: { '@id': 'http://purl.org/dc/terms/accessRights', '@type': '@id' },
+    format: { '@id': 'http://purl.org/dc/terms/format', '@type': '@id' },
+    label: {
+      '@id': 'http://www.w3.org/2004/02/skos/core#label',
+      '@container': '@language'
+    },
+    prefLabel: {
+      '@id': 'http://www.w3.org/2004/02/skos/core#prefLabel',
+      '@container': '@language'
     }
-
-  `,
-    {
-      auth,
-      context: {
-        ...resourceContext,
-        accessURL: { '@id': 'http://www.w3.org/ns/dcat#accessURL', '@type': '@id' },
-        license: { '@id': 'http://purl.org/dc/terms/license', '@type': '@id' },
-        type: { '@id': 'http://purl.org/dc/terms/type', '@type': '@id' },
-        accessRights: { '@id': 'http://purl.org/dc/terms/accessRights', '@type': '@id' },
-        format: { '@id': 'http://purl.org/dc/terms/format', '@type': '@id' }
+  }
+  
+  const frame = {
+    '@context': context,
+    '@type': [
+      'http://www.w3.org/ns/dcat#Distribution',
+    ],
+    contains: {
+      accessRights: {
+        '@embed': '@always',
+      },
+      type: {
+        '@embed': '@always'
+      },
+      format: {
+        '@embed': '@always'
+      },
+      license: {
+        '@embed': '@always'
       }
     }
-  )
-  const distribution = distributionIdResponse?.[0]
-  const distributionUri = distribution['@id']
+  }
 
-  /**
-   * access rights, License, type, access URL and format
-   */
-  const distributionRelatedResponse = await executeSparqlConstruct<OcConcept>(
+  const distributionResponse = await executeSparqlConstruct<OcDistribution>(
     `
     CONSTRUCT {
-      ?accessRights ?p1 ?o1.
-      ?license ?p2 ?o2.
-      ?type ?p3 ?o3.
-      ?format ?p5 ?o5.
+      ?distribution ?p ?o.
+      ?distribution oct:graph ?g.
+      ?o2 ?p3 ?o3.
     }
     WHERE {
-      OPTIONAL {
-        <${distributionUri}> dct:accessRights ?accessRights.
-        ?accessRights ?p1 ?o1.
-      }
-      OPTIONAL {
-        <${distributionUri}> dct:license ?license.
-        ?license ?p2 ?o2.
-      }
-      OPTIONAL {
-        <${distributionUri}> dct:type ?type.
-        ?type ?p3 ?o3.
-      }
-      OPTIONAL {
-        <${distributionUri}> dct:format ?format.
-        ?format ?p5 ?o5.
+      GRAPH ?g {
+        ?distribution a dcat:Distribution;
+                      dct:identifier ?identifier.
+        FILTER (str(?identifier) = "${identifier}")
       }
+
+      ?distribution ?p ?o.
+
+      VALUES ?p2 { dct:accessRights dct:license dct:type dct:format }
+      ?distribution ?p2 ?o2.
+      ?o2 ?p3 ?o3.
     }
 
   `,
     {
       auth,
-      context: {
-        ...resourceContext,
-        label: {
-          '@id': 'http://www.w3.org/2004/02/skos/core#label',
-          '@container': '@language'
-        },
-        prefLabel: {
-          '@id': 'http://www.w3.org/2004/02/skos/core#prefLabel',
-          '@container': '@language'
-        }
-      }
+      context: context,
+      frame: frame
     }
   )
+  const distribution = distributionResponse?.[0]
 
-  const distributionResponse = await Promise.all([
-    distributionRelatedResponse // 0
-  ])
-
-  distribution.license = distributionResponse[0].find(
-    (d) => d['@id'] === (distribution.license as unknown as string)
-  )
-  distribution.type = distributionResponse[0].find(
-    (d) => d['@id'] === (distribution.type as unknown as string)
-  )
-  distribution.accessRights = distributionResponse[0].find(
-    (d) => d['@id'] === (distribution.accessRights as unknown as string)
-  )
-  distribution.format = distributionResponse[0].find(
-    (d) => d['@id'] === (distribution.format as unknown as string)
-  )
   return distribution
 }