Examples with MVEL org.mvel2.MVEL used on opensource projects

Example 21 with MVEL

use of org.mvel2.MVEL in project drools by kiegroup.

the class MVELConsequence method evaluate.

@Override
public void evaluate(KnowledgeHelper knowledgeHelper, WorkingMemory workingMemory) throws Exception {
    // same as lambda consequence...
    Tuple tuple = knowledgeHelper.getTuple();
    Declaration[] declarations = ((RuleTerminalNode) knowledgeHelper.getMatch().getTuple().getTupleSink()).getRequiredDeclarations();
    Variable[] vars = consequence.getVariables();
    // ...but the facts are association of Variable and its value, preserving order.
    Map<Variable, Object> facts = new LinkedHashMap<>();
    int declrCounter = 0;
    for (Variable var : vars) {
        if (var.isFact()) {
            Declaration declaration = declarations[declrCounter++];
            InternalFactHandle fh = tuple.get(declaration);
            facts.put(var, declaration.getValue((InternalWorkingMemory) workingMemory, fh.getObject()));
        } else {
            facts.put(var, workingMemory.getGlobal(var.getName()));
        }
    }
    ScriptBlock scriptBlock = null;
    try {
        scriptBlock = (ScriptBlock) consequence.getBlock();
    } catch (ClassCastException e) {
        throw new RuntimeException("I tried to access a ScriptBlock but it was not. So something is thinking is a MVEL consequence but did not set the MVEL script textual representation", e);
    }
    String originalRHS = scriptBlock.getScript();
    String name = context.getRule().getPackageName() + "." + context.getRule().getName();
    String expression = MVELConsequenceBuilder.processMacros(originalRHS);
    String[] globalIdentifiers = new String[] {};
    String[] default_inputIdentifiers = new String[] { "this", "drools", "kcontext", "rule" };
    String[] inputIdentifiers = Stream.concat(Arrays.asList(default_inputIdentifiers).stream(), facts.entrySet().stream().map(kv -> kv.getKey().getName())).collect(Collectors.toList()).toArray(new String[] {});
    String[] default_inputTypes = new String[] { "org.drools.core.spi.KnowledgeHelper", "org.drools.core.spi.KnowledgeHelper", "org.drools.core.spi.KnowledgeHelper", "org.kie.api.definition.rule.Rule" };
    String[] inputTypes = Stream.concat(Arrays.asList(default_inputTypes).stream(), facts.entrySet().stream().map(kv -> kv.getKey().getType().getName())).collect(Collectors.toList()).toArray(new String[] {});
    // ^^ please notice about inputTypes, it is to use the Class.getName(), because is later used by the Classloader internally in MVEL to load the class,
    // do NOT replace with getCanonicalName() otherwise inner classes will not be loaded correctly.
    int languageLevel = 4;
    boolean strictMode = true;
    boolean readLocalsFromTuple = false;
    EvaluatorWrapper[] operators = new EvaluatorWrapper[] {};
    Declaration[] previousDeclarations = new Declaration[] {};
    Declaration[] localDeclarations = new Declaration[] {};
    String[] otherIdentifiers = new String[] {};
    MVELCompilationUnit cu = new MVELCompilationUnit(name, expression, globalIdentifiers, operators, previousDeclarations, localDeclarations, otherIdentifiers, inputIdentifiers, inputTypes, languageLevel, strictMode, readLocalsFromTuple);
    // TODO unfortunately the MVELDialectRuntimeData would be the one of compile time
    // the one from runtime is not helpful, in fact the dialect registry for runtime is empty:
    // MVELDialectRuntimeData runtimeData = (MVELDialectRuntimeData) context.getPkg().getDialectRuntimeRegistry().getDialectData("mvel");
    MVELDialectRuntimeData runtimeData = new MVELDialectRuntimeData();
    // this classloader will be used by the CompilationUnit to load the imports.
    runtimeData.onAdd(null, Thread.currentThread().getContextClassLoader());
    runtimeData.addPackageImport(context.getPkg().getName());
    runtimeData.addPackageImport("java.lang");
    // therefore we assume for the ScriptBlock all available KBPackages are the default available and imported for the scope of the Script itself.
    for (KiePackage kp : context.getKnowledgePackages()) {
        if (!kp.getName().equals(context.getPkg().getName())) {
            runtimeData.addPackageImport(kp.getName());
        }
    }
    // sometimes here it was passed as a 2nd argument a String?? similar to `rule R in file file.drl`
    Serializable cuResult = cu.getCompiledExpression(runtimeData);
    ExecutableStatement compiledExpression = (ExecutableStatement) cuResult;
    // TODO the part above up to the ExecutableStatement compiledExpression should be cached.
    Map<String, Object> mvelContext = new HashMap<>();
    mvelContext.put("this", knowledgeHelper);
    mvelContext.put("drools", knowledgeHelper);
    mvelContext.put("kcontext", knowledgeHelper);
    mvelContext.put("rule", knowledgeHelper.getRule());
    for (Entry<Variable, Object> kv : facts.entrySet()) {
        mvelContext.put(kv.getKey().getName(), kv.getValue());
    }
    CachingMapVariableResolverFactory cachingFactory = new CachingMapVariableResolverFactory(mvelContext);
    VariableResolverFactory factory = cu.getFactory(knowledgeHelper, ((AgendaItem) knowledgeHelper.getMatch()).getTerminalNode().getRequiredDeclarations(), knowledgeHelper.getRule(), knowledgeHelper.getTuple(), null, (InternalWorkingMemory) workingMemory, workingMemory.getGlobalResolver());
    cachingFactory.setNextFactory(factory);
    MVEL.executeExpression(compiledExpression, knowledgeHelper, cachingFactory);
}

Example 22 with MVEL

use of org.mvel2.MVEL in project drools by kiegroup.

the class MVELExprAnalyzer method analyzeExpression.

// ------------------------------------------------------------
// Instance methods
// ------------------------------------------------------------
/**
 * Analyze an expression.
 *
 * @param expr
 *            The expression to analyze.
 * @param availableIdentifiers
 *            Total set of declarations available.
 *
 * @return The <code>Set</code> of declarations used by the expression.
 * @throws RecognitionException
 *             If an error occurs in the parser.
 */
@SuppressWarnings("unchecked")
public static MVELAnalysisResult analyzeExpression(final PackageBuildContext context, final String expr, final BoundIdentifiers availableIdentifiers, final Map<String, Class<?>> localTypes, String contextIdentifier, Class kcontextClass) {
    if (expr.trim().length() <= 0) {
        MVELAnalysisResult result = analyze((Set<String>) Collections.EMPTY_SET, availableIdentifiers);
        result.setMvelVariables(new HashMap<String, Class<?>>());
        result.setTypesafe(true);
        return result;
    }
    MVEL.COMPILER_OPT_ALLOW_NAKED_METH_CALL = true;
    MVEL.COMPILER_OPT_ALLOW_OVERRIDE_ALL_PROPHANDLING = true;
    MVEL.COMPILER_OPT_ALLOW_RESOLVE_INNERCLASSES_WITH_DOTNOTATION = true;
    MVEL.COMPILER_OPT_SUPPORT_JAVA_STYLE_CLASS_LITERALS = true;
    MVELDialect dialect = (MVELDialect) context.getDialect("mvel");
    ParserConfiguration conf = context.getMVELDialectRuntimeData().getParserConfiguration();
    conf.setClassLoader(context.getKnowledgeBuilder().getRootClassLoader());
    // first compilation is for verification only
    // @todo proper source file name
    final ParserContext parserContext1 = new ParserContext(conf);
    if (localTypes != null) {
        for (Entry entry : localTypes.entrySet()) {
            parserContext1.addInput((String) entry.getKey(), (Class) entry.getValue());
        }
    }
    if (availableIdentifiers.getThisClass() != null) {
        parserContext1.addInput("this", availableIdentifiers.getThisClass());
    }
    if (availableIdentifiers.getOperators() != null) {
        for (Entry<String, EvaluatorWrapper> opEntry : availableIdentifiers.getOperators().entrySet()) {
            parserContext1.addInput(opEntry.getKey(), opEntry.getValue().getClass());
        }
    }
    parserContext1.setStrictTypeEnforcement(false);
    parserContext1.setStrongTyping(false);
    parserContext1.setInterceptors(dialect.getInterceptors());
    Class<?> returnType;
    try {
        returnType = MVEL.analyze(expr, parserContext1);
    } catch (Exception e) {
        BaseDescr base = (context instanceof RuleBuildContext) ? ((RuleBuildContext) context).getRuleDescr() : context.getParentDescr();
        if (e instanceof CompileException && e.getCause() != null && e.getMessage().startsWith("[Error: null]")) {
            // rewrite error message in cause original message is null
            e = new CompileException(e.getCause().toString(), ((CompileException) e).getExpr(), ((CompileException) e).getCursor(), e.getCause());
        }
        DialectUtil.copyErrorLocation(e, context.getParentDescr());
        context.addError(new DescrBuildError(base, context.getParentDescr(), null, "Unable to Analyse Expression " + expr + ":\n" + e.getMessage()));
        return null;
    }
    Set<String> requiredInputs = new HashSet<String>();
    requiredInputs.addAll(parserContext1.getInputs().keySet());
    HashMap<String, Class<?>> variables = (HashMap<String, Class<?>>) ((Map) parserContext1.getVariables());
    if (localTypes != null) {
        for (String str : localTypes.keySet()) {
            // we have to do this due to mvel regressions on detecting true local vars
            variables.remove(str);
        }
    }
    // MVEL includes direct fields of context object in non-strict mode. so we need to strip those
    if (availableIdentifiers.getThisClass() != null) {
        requiredInputs.removeIf(s -> PropertyTools.getFieldOrAccessor(availableIdentifiers.getThisClass(), s) != null);
    }
    // now, set the required input types and compile again
    final ParserContext parserContext2 = new ParserContext(conf);
    parserContext2.setStrictTypeEnforcement(true);
    parserContext2.setStrongTyping(true);
    parserContext2.setInterceptors(dialect.getInterceptors());
    for (String input : requiredInputs) {
        if ("this".equals(input)) {
            continue;
        }
        Class<?> cls = availableIdentifiers.resolveType(input);
        if (cls == null) {
            if (input.equals(contextIdentifier) || input.equals("kcontext")) {
                cls = kcontextClass;
            } else if (input.equals("rule")) {
                cls = Rule.class;
            } else if (localTypes != null) {
                cls = localTypes.get(input);
            }
        }
        if (cls != null) {
            parserContext2.addInput(input, cls);
        }
    }
    if (availableIdentifiers.getThisClass() != null) {
        parserContext2.addInput("this", availableIdentifiers.getThisClass());
    }
    boolean typesafe = context.isTypesafe();
    try {
        returnType = MVEL.analyze(expr, parserContext2);
        typesafe = true;
    } catch (Exception e) {
        // is this an error, or can we fall back to non-typesafe mode?
        if (typesafe) {
            BaseDescr base = (context instanceof RuleBuildContext) ? ((RuleBuildContext) context).getRuleDescr() : context.getParentDescr();
            DialectUtil.copyErrorLocation(e, context.getParentDescr());
            context.addError(new DescrBuildError(base, context.getParentDescr(), null, "Unable to Analyse Expression " + expr + ":\n" + e.getMessage()));
            return null;
        }
    }
    if (typesafe) {
        requiredInputs = new HashSet<String>();
        requiredInputs.addAll(parserContext2.getInputs().keySet());
        requiredInputs.addAll(variables.keySet());
        variables = (HashMap<String, Class<?>>) ((Map) parserContext2.getVariables());
        if (localTypes != null) {
            for (String str : localTypes.keySet()) {
                // we have to do this due to mvel regressions on detecting true local vars
                variables.remove(str);
            }
        }
    }
    MVELAnalysisResult result = analyze(requiredInputs, availableIdentifiers);
    result.setReturnType(returnType);
    result.setMvelVariables(variables);
    result.setTypesafe(typesafe);
    return result;
}

Example 23 with MVEL

use of org.mvel2.MVEL in project drools by kiegroup.

the class MVELExprAnalyzer method getExpressionType.

public static Class<?> getExpressionType(PackageBuildContext context, Map<String, Class<?>> declCls, RuleConditionElement source, String expression) {
    MVELDialectRuntimeData data = (MVELDialectRuntimeData) context.getPkg().getDialectRuntimeRegistry().getDialectData("mvel");
    ParserConfiguration conf = data.getParserConfiguration();
    conf.setClassLoader(context.getKnowledgeBuilder().getRootClassLoader());
    ParserContext pctx = new ParserContext(conf);
    pctx.setStrongTyping(true);
    pctx.setStrictTypeEnforcement(true);
    for (Map.Entry<String, Class<?>> entry : declCls.entrySet()) {
        pctx.addInput(entry.getKey(), entry.getValue());
    }
    for (Declaration decl : source.getOuterDeclarations().values()) {
        pctx.addInput(decl.getBindingName(), decl.getDeclarationClass());
    }
    try {
        return MVEL.analyze(expression, pctx);
    } catch (Exception e) {
        log.warn("Unable to parse expression: " + expression, e);
    }
    return null;
}

Example 24 with MVEL

use of org.mvel2.MVEL in project drools by kiegroup.

the class MVELAccumulator method init.

/* (non-Javadoc)
     * @see org.kie.spi.Accumulator#init(java.lang.Object, org.kie.spi.Tuple, org.kie.rule.Declaration[], org.kie.WorkingMemory)
     */
public void init(Object workingMemoryContext, Object context, Tuple tuple, Declaration[] declarations, WorkingMemory workingMemory) throws Exception {
    Object[] localVars = new Object[initUnit.getOtherIdentifiers().length];
    MVELAccumulatorFactoryContext factoryContext = (MVELAccumulatorFactoryContext) workingMemoryContext;
    VariableResolverFactory factory = factoryContext.getInitFactory();
    initUnit.updateFactory(null, tuple, localVars, (InternalWorkingMemory) workingMemory, workingMemory.getGlobalResolver(), factory);
    InternalKnowledgePackage pkg = workingMemory.getKnowledgeBase().getPackage("MAIN");
    if (pkg != null) {
        MVELDialectRuntimeData data = (MVELDialectRuntimeData) pkg.getDialectRuntimeRegistry().getDialectData("mvel");
        factory.setNextFactory(data.getFunctionFactory());
    }
    MVELSafeHelper.getEvaluator().executeExpression(this.init, null, factory);
    DroolsVarFactory df = (DroolsVarFactory) factory.getNextFactory();
    if (localVars.length > 0) {
        for (int i = 0; i < df.getOtherVarsLength(); i++) {
            localVars[i] = factory.getIndexedVariableResolver(df.getOtherVarsPos() + i).getValue();
        }
    }
    ((MVELAccumulatorContext) context).setVariables(localVars);
}

Example 25 with MVEL

use of org.mvel2.MVEL in project drools by kiegroup.

the class ActivationPropertyHandler method getProperty.

public Object getProperty(String name, Object obj, VariableResolverFactory variableFactory) {
    AgendaItem item = (AgendaItem) obj;
    if ("rule".equals(name)) {
        return item.getRule();
    } else if ("active".equals(name)) {
        return item.isQueued();
    } else if ("objects".equals(name)) {
        return item.getObjects();
    } else if ("factHandles".equals(name)) {
        return item.getFactHandles();
    } else if ("declarationIds".equals(name)) {
        return item.getDeclarationIds();
    } else if ("this".equals(name)) {
        return item;
    }
    // FIXME hack as MVEL seems to be ignoring indexed variables
    VariableResolver vr = variableFactory.getNextFactory().getVariableResolver(name);
    if (vr != null) {
        return vr.getValue();
    }
    Declaration declr = item.getTerminalNode().getSubRule().getOuterDeclarations().get(name);
    if (declr != null) {
        return declr.getValue(null, item.getTuple().get(declr).getObject());
    } else {
        return item.getRule().getMetaData(name);
    }
}