Examples with SafeEvalExpression org.drools.core.rule.EvalCondition.SafeEvalExpression used on opensource projects

Example 1 with SafeEvalExpression

use of org.drools.core.rule.EvalCondition.SafeEvalExpression in project drools by kiegroup.

the class MVELEvalBuilder method build.

/**
 * Builds and returns an Eval Conditional Element
 *
 * @param context The current build context
 * @param descr The Eval Descriptor to build the eval conditional element from
 *
 * @return the Eval Conditional Element
 */
public RuleConditionElement build(final RuleBuildContext context, final BaseDescr descr, final Pattern prefixPattern) {
    boolean typesafe = context.isTypesafe();
    // it must be an EvalDescr
    final EvalDescr evalDescr = (EvalDescr) descr;
    try {
        MVELDialect dialect = (MVELDialect) context.getDialect("mvel");
        Map<String, Declaration> decls = context.getDeclarationResolver().getDeclarations(context.getRule());
        AnalysisResult analysis = context.getDialect().analyzeExpression(context, evalDescr, evalDescr.getContent(), new BoundIdentifiers(DeclarationScopeResolver.getDeclarationClasses(decls), context));
        final BoundIdentifiers usedIdentifiers = analysis.getBoundIdentifiers();
        int i = usedIdentifiers.getDeclrClasses().keySet().size();
        Declaration[] previousDeclarations = new Declaration[i];
        i = 0;
        for (String id : usedIdentifiers.getDeclrClasses().keySet()) {
            previousDeclarations[i++] = decls.get(id);
        }
        Arrays.sort(previousDeclarations, SortDeclarations.instance);
        MVELCompilationUnit unit = dialect.getMVELCompilationUnit((String) evalDescr.getContent(), analysis, previousDeclarations, null, null, context, "drools", KnowledgeHelper.class, false, MVELCompilationUnit.Scope.EXPRESSION);
        final EvalCondition eval = new EvalCondition(previousDeclarations);
        MVELEvalExpression expr = new MVELEvalExpression(unit, dialect.getId());
        eval.setEvalExpression(KiePolicyHelper.isPolicyEnabled() ? new SafeEvalExpression(expr) : expr);
        MVELDialectRuntimeData data = (MVELDialectRuntimeData) context.getPkg().getDialectRuntimeRegistry().getDialectData("mvel");
        data.addCompileable(eval, expr);
        expr.compile(data, context.getRule());
        return eval;
    } catch (final Exception e) {
        copyErrorLocation(e, evalDescr);
        context.addError(new DescrBuildError(context.getParentDescr(), evalDescr, e, "Unable to build expression for 'eval':" + e.getMessage() + " '" + evalDescr.getContent() + "'"));
        return null;
    } finally {
        context.setTypesafe(typesafe);
    }
}