public void setGraphRestriction(BinaryUnion<Variable, IRI> graphRestriction) {
// if (this.graphRestriction == null)
{
if (graphRestriction != null
&& graphRestriction.isFirstType()
&& gatherVariables().contains(graphRestriction.getFirst())
&& !getProjectedVariables().contains(graphRestriction.getFirst())) {
// graph restriction variable already used in the local graph pattern
// and is not visible outside
// we need to
// 1) use a new variable v (not used in this pattern or its ancestors) for the graph
// restriction
// 2) project v
// 3) set the graph restriction to v
// 4) add in this subselect pattern a filter ?v = ?graphRestriction
Set<Variable> vars = HashSetFactory.make();
Pattern top = getTopAncestor();
if (top != null) {
vars.addAll(Planner.gatherInScopeVariables(top));
if (top.getOptionalPatterns() != null) {
for (Pattern op : top.getOptionalPatterns()) {
vars.addAll(Planner.gatherInScopeVariables(op));
}
}
}
vars.addAll(gatherVariables());
String prefix = "graphRestrictionGeneratedVar_";
int id = OCUtils.nextAvailableSuffixVariable(OCUtils.getVariables(vars), prefix);
Variable v = new Variable(prefix + id);
this.graphRestriction = new BinaryUnion<Variable, IRI>();
this.graphRestriction.setFirst(v);
if (selectClause.getProjectedVariables() == null
|| selectClause.getProjectedVariables().isEmpty()) {
for (ProjectedVariable pv : gatherRealProjectedVariables()) {
selectClause.addProjectedVariable(pv);
}
}
selectClause.addProjectedVariable(new ProjectedVariable(v.getName()));
// getParent().addFilter(new RelationalExpression(new
// VariableExpression(graphRestriction.getFirst().getName()),
// new VariableExpression(v.getName()), ERelationalOp.EQUAL));
} else {
this.graphRestriction = graphRestriction;
}
}
}
public Set<Variable> gatherProjectedVariables() {
Set<Variable> allVars = new LinkedHashSet<Variable>();
List<ProjectedVariable> pvList = selectClause.getProjectedVariables();
if (pvList != null && pvList.size() > 0) {
for (ProjectedVariable pv : pvList) {
allVars.add(pv.getVariable());
}
return allVars;
} else {
allVars.addAll(Planner.gatherInScopeVariables(graphPattern));
if (graphPattern.getOptionalPatterns() != null) {
for (Pattern op : graphPattern.getOptionalPatterns()) {
allVars.addAll(Planner.gatherInScopeVariables(op));
}
}
return allVars;
}
}
