PatternBuffer

PatternBuffer is a Pharo/Smalltalk client for querying RDF databases.

Requirements

For Linux (Ubuntu 20.04 Recommended)

• Pharo (10.0 recommended)
• RDFLib installed on system Python

Loading instructions

To load the latest release, open a playground window (Ctrl+O+W) and evaluate:

Metacello new baseline: 'PatternBuffer';
    repository: 'github://capsulecorplab/patternbuffer:v0.4.1';
    load.

NOTE: Evaluate by highlighting the code, then either right-click on the highlighted code and click Do it or press Ctrl+D.

Example Usage

Once the PatternBuffer package has been loaded into your Pharo image, you can run a SPARQL query against an RDF datastore.

For example, evaluate and inspect the following in a playground window (Ctrl+O+W) to execute a query for assemblies & subassemblies against a TTL file downloaded from the firesat database:

firesatClient := PBSPARQL new
    datastore: '/home/kasm-user/firesat-example/firesat.ttl';
    query: 'PREFIX fse:   <http://opencaesar.io/examples/firesat/disciplines/fse/fse#>
PREFIX base:   <http://imce.jpl.nasa.gov/foundation/base#>

SELECT ?assembly ?subassembly

WHERE {
	?assembly base:contains ?subassembly
}'.

Results of the SPARQL query can be viewed as a JSON object,

firesatClient resultAsJSON.

or as a table,

firesatClient resultAsTable.

NOTE: Evaluate and inspect the result by highlighting the code, then either right-click on the highlighted code and click Do it and go or press Ctrl+G.