[JENA-2242] Include VALUES clause in string when stringifying a WhereBuilder

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: Jena 4.3.2
• Fix Version/s: Jena 4.4.0
• Component/s: QueryBuilder
• Assignee: Claude Warren
• Reporter: Kelvin Qian
• Created: 04/Jan/22 15:54
• Updated: 02/Feb/22 19:31
• Resolved: 07/Jan/22 11:10

Description

Currently when stringifying a WhereBuilder (e.g. for debugging), any VALUES clause is not included in the output of .toString:

import java.util.ArrayList;
import java.util.HashMap;

import org.apache.jena.graph.Node;
import org.apache.jena.grpah.Triple;
import org.apache.jena.arq.querybuilder.Converters;

import org.apache.jena.arq.querybuilder.WhereBuilder;
 
// Node creation
Node svarNode = Converters.checkVar(NodeFactory.createVariable("s"));
Node pvarNode = Converters.checkVar(NodeFactory.createVariable("p"));
Node ovarNode = Converters.checkVar(NodeFactory.createVariable("o"));

// Values map creation
ArrayList<Node> subjColl = new ArrayList<>();
subjColl.add(NodeFactory.createURI("http://example.org#subject"));

HashMap<Node, ArrayList<Node>> valMap = new HashMap<>();
valMap.put(svarNode, subjColl);

// WhereBuilder creation
WhereBuilder wb = new WhereBuilder();
wb.addWhere(svarNode, pvarNode, ovarNode);
wb.addWhereValueVars(valMap);

wb.toString();

// WHERE { ?s ?p ?o }

It is only when you add the WhereBuilder to another builder, e.g. a ConstructBuilder, when you are able to visualize the VALUES clause:

import org.apache.jena.arq.querybuilder.ConstructBuilder;

ConstructBuilder cb = new ConstructBuilder();
cb.addConstruct(new Triple(svarNode, pvarNode, ovarNode));
cb.addWhere(wb);

cb.toString();

// CONSTRUCT 
//   { 
//     ?s ?p ?o .
//   }
// WHERE
//   { ?s  ?p  ?o
//     VALUES ( ?s ) { ( <http://example.org#subject> ) }
//   }

Ideally we would like to visualize the VALUES clause by including it in the result string while stringifying the WhereBuilder, not just with the ConstructBuilder. This would improve the development experience by allowing us to focus on debugging the WHERE clause, without having to consider the containing query or update.

Issue Links

• links to: GitHub Pull Request #1158