@SuppressWarnings("unchecked")
public RuleConditionElement build(
final RuleBuildContext context, final BaseDescr descr, final Pattern prefixPattern) {
boolean typesafe = context.isTypesafe();
try {
final AccumulateDescr accumDescr = (AccumulateDescr) descr;
if (!accumDescr.hasValidInput()) {
return null;
}
final RuleConditionBuilder builder =
(RuleConditionBuilder) context.getDialect().getBuilder(accumDescr.getInput().getClass());
// create source CE
final RuleConditionElement source = builder.build(context, accumDescr.getInput());
if (source == null) {
return null;
}
MVELDialect dialect = (MVELDialect) context.getDialect();
Map<String, Declaration> decls =
context.getDeclarationResolver().getDeclarations(context.getRule());
Map<String, Declaration> sourceOuterDeclr = source.getOuterDeclarations();
Map<String, Declaration> mergedDecl = new HashMap(decls);
mergedDecl.putAll(sourceOuterDeclr);
Map<String, Class<?>> declarationClasses =
DeclarationScopeResolver.getDeclarationClasses(decls);
declarationClasses.putAll(DeclarationScopeResolver.getDeclarationClasses(sourceOuterDeclr));
BoundIdentifiers boundIds =
new BoundIdentifiers(declarationClasses, context.getKnowledgeBuilder().getGlobals());
boundIds.setDeclarations(mergedDecl);
Accumulator[] accumulators;
final boolean readLocalsFromTuple =
PackageBuilderUtil.isReadLocalsFromTuple(context, accumDescr, source);
if (accumDescr.isExternalFunction()) {
// uses accumulate functions
accumulators =
buildExternalFunctions(
context,
accumDescr,
dialect,
decls,
sourceOuterDeclr,
boundIds,
readLocalsFromTuple);
} else {
// it is a custom accumulate
accumulators =
buildCustomAccumulate(
context,
accumDescr,
dialect,
decls,
sourceOuterDeclr,
boundIds,
readLocalsFromTuple);
}
List<Declaration> requiredDeclarations = new ArrayList<Declaration>();
for (Accumulator acc : accumulators) {
MvelAccumulator mvelAcc = (MvelAccumulator) acc;
Collections.addAll(requiredDeclarations, mvelAcc.getRequiredDeclarations());
}
MVELDialectRuntimeData data =
(MVELDialectRuntimeData)
context.getPkg().getDialectRuntimeRegistry().getDialectData("mvel");
Accumulate accumulate;
if (accumDescr.isMultiFunction()) {
accumulate =
new MultiAccumulate(
source,
requiredDeclarations.toArray(new Declaration[requiredDeclarations.size()]),
accumulators);
int index = 0;
for (Accumulator accumulator : accumulators) {
data.addCompileable(
((MultiAccumulate) accumulate).new Wirer(index++), (MVELCompileable) accumulator);
((MVELCompileable) accumulator).compile(data, context.getRule());
}
} else {
accumulate =
new SingleAccumulate(
source,
requiredDeclarations.toArray(new Declaration[requiredDeclarations.size()]),
accumulators[0]);
data.addCompileable(
((SingleAccumulate) accumulate).new Wirer(), (MVELCompileable) accumulators[0]);
((MVELCompileable) accumulators[0]).compile(data, context.getRule());
}
return accumulate;
} catch (Exception e) {
DialectUtil.copyErrorLocation(e, descr);
context.addError(
new DescrBuildError(
context.getParentDescr(),
descr,
e,
"Unable to build expression for 'accumulate' : " + e.getMessage()));
return null;
} finally {
context.setTypesafe(typesafe);
}
}