public void visitExprConstraintDescr(final ExprConstraintDescr descr) {
this.template =
"<expr>"
+ XmlDumper.eol
+ StringUtils.escapeXmlString(descr.getExpression())
+ XmlDumper.eol
+ "</expr>";
// if ( !descr.getRestrictions().isEmpty() ) {
// this.template = "<field-constraint field-name=\"" + descr.getFieldName() + "\"> "
// + XmlDumper.eol + processFieldConstraint( descr.getRestrictions() ) + XmlDumper.eol +
// "</field-constraint>";
// }
}
@SuppressWarnings("unchecked")
public RuleConditionElement build(
RuleBuildContext context, BaseDescr descr, Pattern prefixPattern, Query query) {
PatternDescr patternDescr = (PatternDescr) descr;
Declaration[] params = query.getParameters();
List<BaseDescr> args = (List<BaseDescr>) patternDescr.getDescrs();
List<Integer> declrIndexes = new ArrayList<Integer>();
List<Integer> varIndexes = new ArrayList<Integer>();
List<Object> arguments = new ArrayList<Object>(params.length);
for (int i = 0; i < params.length; i++) {
// as these could be set in any order, initialise first, to allow setting later.
arguments.add(null);
}
List<Declaration> requiredDeclarations = new ArrayList<Declaration>();
ObjectType argsObjectType = ClassObjectType.ObjectArray_ObjectType;
InternalReadAccessor arrayReader = new SelfReferenceClassFieldReader(Object[].class, "this");
Pattern pattern = new Pattern(context.getNextPatternId(), 0, argsObjectType, null);
// Deal with the constraints, both positional and bindings
for (int i = 0, length = args.size(); i < length; i++) {
BaseDescr base = args.get(i);
String expression = null;
boolean isPositional = false;
boolean isBinding = false;
BindingDescr bind = null;
ConstraintConnectiveDescr result = null;
if (base instanceof BindingDescr) {
bind = (BindingDescr) base;
expression =
bind.getVariable() + (bind.isUnification() ? " := " : " : ") + bind.getExpression();
isBinding = true;
} else {
if (base instanceof ExprConstraintDescr) {
ExprConstraintDescr ecd = (ExprConstraintDescr) base;
expression = ecd.getExpression();
isPositional = ecd.getType() == ExprConstraintDescr.Type.POSITIONAL;
} else {
expression = base.getText();
}
result = parseExpression(context, patternDescr, expression);
if (result == null) {
// error, can't parse expression.
context.addError(
new DescrBuildError(
context.getParentDescr(),
descr,
null,
"Unable to parse constraint: \n" + expression));
continue;
}
isBinding =
result.getDescrs().size() == 1 && result.getDescrs().get(0) instanceof BindingDescr;
if (isBinding) {
bind = (BindingDescr) result.getDescrs().get(0);
}
}
if ((!isPositional) && (!isBinding)) {
// error, can't have non binding slots.
context.addError(
new DescrBuildError(
context.getParentDescr(),
descr,
null,
"Query's must use positional or bindings, not field constraints:\n" + expression));
continue;
} else if (isPositional && isBinding) {
// error, can't have positional binding slots.
context.addError(
new DescrBuildError(
context.getParentDescr(),
descr,
null,
"Query's can't use positional bindings:\n" + expression));
continue;
} else if (isPositional) {
processPositional(
context,
query,
params,
declrIndexes,
varIndexes,
arguments,
requiredDeclarations,
arrayReader,
pattern,
base,
expression,
result);
} else {
// it is binding
processBinding(
context,
descr,
params,
declrIndexes,
varIndexes,
arguments,
requiredDeclarations,
arrayReader,
pattern,
bind,
result);
}
}
Declaration[] declrsArray =
requiredDeclarations.toArray(new Declaration[requiredDeclarations.size()]);
int[] declrIndexArray = new int[declrIndexes.size()];
for (int i = 0; i < declrsArray.length; i++) {
declrIndexArray[i] = declrIndexes.get(i);
}
int[] varIndexesArray = new int[varIndexes.size()];
for (int i = 0; i < varIndexesArray.length; i++) {
varIndexesArray[i] = varIndexes.get(i);
}
return new QueryElement(
pattern,
query.getName(),
arguments.toArray(new Object[arguments.size()]),
declrsArray,
declrIndexArray,
varIndexesArray,
!patternDescr.isQuery());
}
@Test
public void testRuleWithQuery() throws Exception {
final PackageBuilder builder = new PackageBuilder();
final PackageDescr packageDescr = new PackageDescr("p1");
QueryDescr queryDescr = new QueryDescr("query1");
queryDescr.addParameter("String", "$name");
queryDescr.addParameter("int", "$age");
queryDescr.addParameter("String", "$likes");
packageDescr.addRule(queryDescr);
AndDescr lhs = new AndDescr();
queryDescr.setLhs(lhs);
PatternDescr pattern = new PatternDescr(Person.class.getName());
lhs.addDescr(pattern);
pattern.addConstraint(new BindingDescr("$name", "name", true));
pattern.addConstraint(new BindingDescr("$age", "age", true));
pattern.addConstraint(new BindingDescr("$likes", "likes", true));
RuleDescr ruleDescr = new RuleDescr("rule-1");
packageDescr.addRule(ruleDescr);
lhs = new AndDescr();
ruleDescr.setLhs(lhs);
pattern = new PatternDescr(Cheese.class.getName());
lhs.addDescr(pattern);
pattern.addConstraint(new BindingDescr("$type", "type"));
pattern = new PatternDescr("query1");
pattern.setQuery(true);
lhs.addDescr(pattern);
ExprConstraintDescr expr = new ExprConstraintDescr("'bobba'");
expr.setPosition(0);
expr.setType(Type.POSITIONAL);
pattern.addConstraint(expr);
expr = new ExprConstraintDescr("$age");
expr.setPosition(1);
expr.setType(Type.POSITIONAL);
pattern.addConstraint(expr);
expr = new ExprConstraintDescr("$type");
expr.setPosition(2);
expr.setType(Type.POSITIONAL);
pattern.addConstraint(expr);
ruleDescr.setConsequence("System.out.println(\"age: \" + $age);");
builder.addPackage(packageDescr);
assertLength(0, builder.getErrors().getErrors());
KnowledgeBase kbase = KnowledgeBaseFactory.newKnowledgeBase();
kbase.addKnowledgePackages(
Arrays.asList(new KnowledgePackage[] {new KnowledgePackageImp(builder.getPackage())}));
final KieSession session = kbase.newStatefulKnowledgeSession();
session.insert(new Person("bobba", "stilton", 90));
session.insert(new Person("bobba", "brie", 80));
session.insert(new Person("bobba", "brie", 75));
session.insert(new Person("darth", "brie", 100));
session.insert(new Person("luke", "brie", 25));
session.insert(new Cheese("brie", 25));
session.fireAllRules();
}
