Semantic Facets
A library for automatic facet generation over SPARQL-endpoints.
The provided code currently just supports the SPARQL endpoint of Wikidata. However, the library can be adapted to any knowledge graph.
Install
semanticFacets
is available on npm.
npm install semanticfacets --save
Tests
To run the test first download the repository and install the dependencies.
Then run npm test
.
npm install
npm test
Note that some tests will connect to the Wikidata SPARQL endpoint.
Usage
import { getFacets, ThrottledRequest } from 'semanticfacets';
// get the request from somewhere
const iris = [ /* some Wikidata resource IRIs */ ];
// default endpoint is set to Wikidata
const connection = ThrottledRequest();
const facets = await getFacets( connection, iris, 5 );
// display facets
// ...
API
getFacets( connection, iris, facetCount )
Main entry point to retrieve the facets.
-
connection( query, options )
... a callback to run SPARQL queries-
query
... a string containing the query itself - returns a flattened object containing the query results
-
-
iris
... an array of resource IRIs given as string -
facetCount
... the number of facets to retrieve - returns a
Promise
to an array ofFacet
-objects
ThrottledRequest( endpoint, maxRequests )
Factory to create a connection callback for getFacets()
.
-
endpoint
... a string containing the URL to a SPARQL endpoint; defaults to the Wikidata endpoint -
maxRequests
... maximum number of parallel requests; defaults to 5 - returns a connection callback function for
getFacets()
Results
Facet
Wrapper for a single facet
Properties
-
datatype
... the datatype of this facet's facet values given as an IRI -
path
... the property path for this facet; array ofProperty
-
values
... the facet values for this facet; array ofValue
Property
Wrapper for RDF-properties
Properties
-
iri
... the IRI of this property -
entity
... the associated entity's IRI for this property -
label
... the label for this property
Value
Wrapper for facet values
Properties
-
iri
... the IRI representing this value ornull
for quantitative facets -
label
... the label for this value -
count
... the value size, i.e. number of input resources connected this value
Benchmarking
In the development we used a bunch of scripts helping us to understand the facet generation process and measure its performance.
All scripts are included in the repository under /perf/
and can be run using npm run [name]
.
To configure the respective test, adapt the configuration object at the top of the respective script.
benchmark
Benchmarks the overall facet generation process.
countCandidates
Attempts to retrieve the number of candidates from the SPARQL endpoint for varying path lengths.
testSemanticSimilarity
Runs the semantic similarity for a selected subset of entities.
trackQueries
Measures the number of executions and their respective runtime for all SPARQL queries.