Examples with MVELAccumulatorFunctionExecutor org.drools.core.base.accumulators.MVELAccumulatorFunctionExecutor used on opensource projects

Example 1 with MVELAccumulatorFunctionExecutor

use of org.drools.core.base.accumulators.MVELAccumulatorFunctionExecutor in project drools by kiegroup.

the class MVELAccumulateBuilder method buildExternalFunctions.

private Accumulator[] buildExternalFunctions(final RuleBuildContext context, final AccumulateDescr accumDescr, MVELDialect dialect, Map<String, Declaration> decls, Map<String, Declaration> sourceOuterDeclr, BoundIdentifiers boundIds, boolean readLocalsFromTuple) {
    Accumulator[] accumulators;
    List<AccumulateFunctionCallDescr> functions = accumDescr.getFunctions();
    accumulators = new Accumulator[functions.size()];
    // creating the custom array reader
    InternalReadAccessor arrayReader = new SelfReferenceClassFieldReader(Object[].class);
    int index = 0;
    Pattern pattern = (Pattern) context.getDeclarationResolver().peekBuildStack();
    for (AccumulateFunctionCallDescr func : functions) {
        // build an external function executor
        AccumulateFunction function = context.getConfiguration().getAccumulateFunction(func.getFunction());
        if (function == null) {
            // might have been imported in the package
            function = context.getPkg().getAccumulateFunctions().get(func.getFunction());
        }
        if (function == null) {
            context.addError(new DescrBuildError(accumDescr, context.getRuleDescr(), null, "Unknown accumulate function: '" + func.getFunction() + "' on rule '" + context.getRuleDescr().getName() + "'. All accumulate functions must be registered before building a resource."));
            return null;
        }
        final AnalysisResult analysis = dialect.analyzeExpression(context, accumDescr, func.getParams().length > 0 ? func.getParams()[0] : "\"\"", boundIds);
        MVELCompilationUnit unit = dialect.getMVELCompilationUnit(func.getParams().length > 0 ? func.getParams()[0] : "\"\"", analysis, getUsedDeclarations(decls, analysis), getUsedDeclarations(sourceOuterDeclr, analysis), null, context, "drools", KnowledgeHelper.class, readLocalsFromTuple, MVELCompilationUnit.Scope.CONSTRAINT);
        accumulators[index] = new MVELAccumulatorFunctionExecutor(unit, function);
        // if there is a binding, create the binding
        if (func.getBind() != null) {
            if (context.getDeclarationResolver().isDuplicated(context.getRule(), func.getBind(), function.getResultType().getName())) {
                if (!func.isUnification()) {
                    context.addError(new DescrBuildError(context.getParentDescr(), accumDescr, null, "Duplicate declaration for variable '" + func.getBind() + "' in the rule '" + context.getRule().getName() + "'"));
                } else {
                    Declaration inner = context.getDeclarationResolver().getDeclaration(func.getBind());
                    Constraint c = new MvelConstraint(Collections.singletonList(context.getPkg().getName()), accumDescr.isMultiFunction() ? "this[ " + index + " ] == " + func.getBind() : "this == " + func.getBind(), new Declaration[] { inner }, null, null, IndexUtil.ConstraintType.EQUAL, context.getDeclarationResolver().getDeclaration(func.getBind()), accumDescr.isMultiFunction() ? new ArrayElementReader(arrayReader, index, function.getResultType()) : new SelfReferenceClassFieldReader(function.getResultType()), true);
                    ((MutableTypeConstraint) c).setType(Constraint.ConstraintType.BETA);
                    pattern.addConstraint(c);
                    index++;
                }
            } else {
                Declaration declr = pattern.addDeclaration(func.getBind());
                if (accumDescr.isMultiFunction()) {
                    declr.setReadAccessor(new ArrayElementReader(arrayReader, index, function.getResultType()));
                } else {
                    declr.setReadAccessor(new SelfReferenceClassFieldReader(function.getResultType()));
                }
            }
        }
        index++;
    }
    return accumulators;
}