/*
* Copyright 2006 JBoss Inc
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.drools.rule.builder;
import static org.drools.rule.builder.dialect.DialectUtil.copyErrorLocation;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Date;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.regex.Matcher;
import org.antlr.runtime.ANTLRStringStream;
import org.antlr.runtime.RecognitionException;
import org.drools.base.ClassObjectType;
import org.drools.base.DroolsQuery;
import org.drools.base.EvaluatorWrapper;
import org.drools.base.FieldFactory;
import org.drools.base.ValueType;
import org.drools.base.evaluators.EvaluatorDefinition.Target;
import org.drools.base.evaluators.Operator;
import org.drools.base.mvel.ActivationPropertyHandler;
import org.drools.base.mvel.MVELCompilationUnit.PropertyHandlerFactoryFixer;
import org.drools.base.mvel.MVELCompileable;
import org.drools.common.AgendaItem;
import org.drools.compiler.AnalysisResult;
import org.drools.compiler.BoundIdentifiers;
import org.drools.compiler.DescrBuildError;
import org.drools.compiler.Dialect;
import org.drools.compiler.DrlExprParser;
import org.drools.compiler.DroolsParserException;
import org.drools.compiler.PackageRegistry;
import org.drools.core.util.ClassUtils;
import org.drools.core.util.StringUtils;
import org.drools.factmodel.ClassDefinition;
import org.drools.factmodel.FieldDefinition;
import org.drools.facttemplates.FactTemplate;
import org.drools.facttemplates.FactTemplateFieldExtractor;
import org.drools.facttemplates.FactTemplateObjectType;
import org.drools.lang.DRLLexer;
import org.drools.lang.MVELDumper;
import org.drools.lang.descr.AtomicExprDescr;
import org.drools.lang.descr.BaseDescr;
import org.drools.lang.descr.BehaviorDescr;
import org.drools.lang.descr.BindingDescr;
import org.drools.lang.descr.ConstraintConnectiveDescr;
import org.drools.lang.descr.ExprConstraintDescr;
import org.drools.lang.descr.LiteralRestrictionDescr;
import org.drools.lang.descr.OperatorDescr;
import org.drools.lang.descr.PatternDescr;
import org.drools.lang.descr.PredicateDescr;
import org.drools.lang.descr.RelationalExprDescr;
import org.drools.lang.descr.ReturnValueRestrictionDescr;
import org.drools.reteoo.RuleTerminalNode.SortDeclarations;
import org.drools.rule.AbstractCompositeConstraint;
import org.drools.rule.Behavior;
import org.drools.rule.Declaration;
import org.drools.rule.From;
import org.drools.rule.MVELDialectRuntimeData;
import org.drools.rule.MutableTypeConstraint;
import org.drools.rule.Pattern;
import org.drools.rule.PatternSource;
import org.drools.rule.PredicateConstraint;
import org.drools.rule.Query;
import org.drools.rule.ReturnValueRestriction;
import org.drools.rule.Rule;
import org.drools.rule.RuleConditionElement;
import org.drools.rule.SlidingLengthWindow;
import org.drools.rule.SlidingTimeWindow;
import org.drools.rule.TypeDeclaration;
import org.drools.rule.UnificationRestriction;
import org.drools.rule.VariableRestriction;
import org.drools.rule.builder.dialect.mvel.MVELDialect;
import org.drools.spi.AcceptsReadAccessor;
import org.drools.spi.Constraint;
import org.drools.spi.Constraint.ConstraintType;
import org.drools.spi.Evaluator;
import org.drools.spi.FieldValue;
import org.drools.spi.InternalReadAccessor;
import org.drools.spi.ObjectType;
import org.drools.spi.PatternExtractor;
import org.drools.spi.Restriction;
import org.drools.time.TimeUtils;
import org.mvel2.MVEL;
import org.mvel2.ParserConfiguration;
import org.mvel2.ParserContext;
import org.mvel2.integration.PropertyHandler;
import org.mvel2.integration.PropertyHandlerFactory;
import org.mvel2.util.PropertyTools;
import static org.drools.rule.builder.ConstraintBuilder.*;
/**
* A builder for patterns
*/
public class PatternBuilder
implements
RuleConditionBuilder {
private static final java.util.regex.Pattern evalRegexp = java.util.regex.Pattern.compile( "^eval\\s*\\(",
java.util.regex.Pattern.MULTILINE );
public PatternBuilder() {
}
public RuleConditionElement build( RuleBuildContext context,
BaseDescr descr ) {
boolean typeSafe = context.isTypesafe();
try {
return this.build( context,
descr,
null );
} finally {
context.setTypesafe( typeSafe );
}
}
/**
* Build a pattern for the given descriptor in the current
* context and using the given utils object
*
* @param context
* @param descr
* @param prefixPattern
* @return
*/
@SuppressWarnings("unchecked")
public RuleConditionElement build( RuleBuildContext context,
BaseDescr descr,
Pattern prefixPattern ) {
final PatternDescr patternDescr = (PatternDescr) descr;
if ( patternDescr.getObjectType() == null || patternDescr.getObjectType().equals( "" ) ) {
context.getErrors().add( new DescrBuildError( context.getParentDescr(),
patternDescr,
null,
"ObjectType not correctly defined" ) );
return null;
}
ObjectType objectType = null;
final FactTemplate factTemplate = context.getPkg().getFactTemplate( patternDescr.getObjectType() );
if ( factTemplate != null ) {
objectType = new FactTemplateObjectType( factTemplate );
} else {
try {
final Class< ? > userProvidedClass = context.getDialect().getTypeResolver().resolveType( patternDescr.getObjectType() );
PackageRegistry pkgr = context.getPackageBuilder().getPackageRegistry( ClassUtils.getPackage( userProvidedClass ) );
org.drools.rule.Package pkg = pkgr == null ? context.getPkg() : pkgr.getPackage();
final boolean isEvent = pkg.isEvent( userProvidedClass );
objectType = new ClassObjectType( userProvidedClass,
isEvent );
} catch ( final ClassNotFoundException e ) {
// swallow as we'll do another check in a moment and then record the problem
}
}
// lets see if it maps to a query
if ( objectType == null ) {
RuleConditionElement rce = null;
// it might be a recursive query, so check for same names
if ( context.getRule().getName().equals( patternDescr.getObjectType() ) ) {
// it's a query so delegate to the QueryElementBuilder
QueryElementBuilder qeBuilder = new QueryElementBuilder();
rce = qeBuilder.build( context,
descr,
prefixPattern,
(Query) context.getRule() );
}
if ( rce == null ) {
Rule rule = context.getPkg().getRule( patternDescr.getObjectType() );
if ( rule != null && rule instanceof Query ) {
// it's a query so delegate to the QueryElementBuilder
QueryElementBuilder qeBuilder = new QueryElementBuilder();
rce = qeBuilder.build( context,
descr,
prefixPattern,
(Query) rule );
}
// try package imports
for ( String importName : context.getDialect().getTypeResolver().getImports() ) {
importName = importName.trim();
int pos = importName.indexOf( '*' );
if ( pos >= 0 ) {
String pkgName = importName.substring( 0,
pos - 1 );
PackageRegistry pkgReg = context.getPackageBuilder().getPackageRegistry( pkgName );
if ( pkgReg != null ) {
rule = pkgReg.getPackage().getRule( patternDescr.getObjectType() );
if ( rule != null && rule instanceof Query ) {
// it's a query so delegate to the QueryElementBuilder
QueryElementBuilder qeBuilder = new QueryElementBuilder();
rce = qeBuilder.build( context,
descr,
prefixPattern,
(Query) rule );
break;
}
}
}
}
}
if ( rce == null ) {
// this isn't a query either, so log an error
context.getErrors().add( new DescrBuildError( context.getParentDescr(),
patternDescr,
null,
"Unable to resolve ObjectType '" + patternDescr.getObjectType() + "'" ) );
}
return rce;
}
Pattern pattern;
boolean duplicateBindings = context.getDeclarationResolver().isDuplicated( context.getRule(),
patternDescr.getIdentifier() );
if ( !StringUtils.isEmpty( patternDescr.getIdentifier() ) && !duplicateBindings ) {
pattern = new Pattern( context.getNextPatternId(),
0, // offset is 0 by default
objectType,
patternDescr.getIdentifier(),
patternDescr.isInternalFact() );
if ( objectType instanceof ClassObjectType ) {
// make sure PatternExtractor is wired up to correct ClassObjectType and set as a target for rewiring
context.getPkg().getClassFieldAccessorStore().getClassObjectType( ((ClassObjectType) objectType),
(PatternExtractor) pattern.getDeclaration().getExtractor() );
}
} else {
pattern = new Pattern( context.getNextPatternId(),
0, // offset is 0 by default
objectType,
null );
}
if ( ClassObjectType.Activation_ObjectType.isAssignableFrom( pattern.getObjectType() ) ) {
PropertyHandler handler = PropertyHandlerFactory.getPropertyHandler( AgendaItem.class );
if ( handler == null ) {
PropertyHandlerFactoryFixer.getPropertyHandlerClass().put( AgendaItem.class,
new ActivationPropertyHandler() );
}
}
if ( duplicateBindings ) {
if ( patternDescr.isUnification() ) {
// rewrite existing bindings into == constraints, so it unifies
build( context,
patternDescr,
pattern,
patternDescr,
"this == " + patternDescr.getIdentifier() );
} else {
// This declaration already exists, so throw an Exception
context.getErrors().add( new DescrBuildError( context.getParentDescr(),
patternDescr,
null,
"Duplicate declaration for variable '" + patternDescr.getIdentifier() + "' in the rule '" + context.getRule().getName() + "'" ) );
}
}
if ( objectType instanceof ClassObjectType ) {
// make sure the Pattern is wired up to correct ClassObjectType and set as a target for rewiring
context.getPkg().getClassFieldAccessorStore().getClassObjectType( ((ClassObjectType) objectType),
pattern );
}
// adding the newly created pattern to the build stack this is necessary in case of local declaration usage
context.getBuildStack().push( pattern );
if ( pattern.getObjectType() instanceof ClassObjectType ) {
Class< ? > cls = ((ClassObjectType) pattern.getObjectType()).getClassType();
TypeDeclaration typeDeclr = context.getPackageBuilder().getTypeDeclaration( cls );
if ( typeDeclr != null ) {
context.setTypesafe( typeDeclr.isTypesafe() );
} else {
context.setTypesafe( true );
}
}
// Process all constraints
processConstraintsAndBinds( context,
patternDescr,
pattern );
if ( patternDescr.getSource() != null ) {
// we have a pattern source, so build it
RuleConditionBuilder builder = (RuleConditionBuilder) context.getDialect().getBuilder( patternDescr.getSource().getClass() );
PatternSource source = (PatternSource) builder.build( context,
patternDescr.getSource() );
if ( source instanceof From ) {
((From) source).setResultPattern( pattern );
}
pattern.setSource( source );
}
for ( BehaviorDescr behaviorDescr : patternDescr.getBehaviors() ) {
if ( pattern.getObjectType().isEvent() ) {
if ( Behavior.BehaviorType.TIME_WINDOW.matches( behaviorDescr.getSubType() ) ) {
SlidingTimeWindow window = new SlidingTimeWindow( TimeUtils.parseTimeString( behaviorDescr.getParameters().get( 0 ) ) );
pattern.addBehavior( window );
} else if ( Behavior.BehaviorType.LENGTH_WINDOW.matches( behaviorDescr.getSubType() ) ) {
SlidingLengthWindow window = new SlidingLengthWindow( Integer.valueOf( behaviorDescr.getParameters().get( 0 ) ) );
pattern.addBehavior( window );
}
} else {
// Some behaviors can only be assigned to patterns declared as events
context.getErrors().add( new DescrBuildError( context.getParentDescr(),
patternDescr,
null,
"A Sliding Window behavior can only be assigned to patterns declared with @role( event ). The pattern '" + pattern.getObjectType() + "' in the rule '" + context.getRule().getName()
+ "' is not declared as an Event." ) );
}
}
// poping the pattern
context.getBuildStack().pop();
return pattern;
}
/**
* Process all constraints and bindings on this pattern
*
* @param context
* @param patternDescr
* @param pattern
*/
private void processConstraintsAndBinds( final RuleBuildContext context,
final PatternDescr patternDescr,
final Pattern pattern ) {
for ( BaseDescr b : patternDescr.getDescrs() ) {
String expression;
boolean isPositional = false;
if ( b instanceof BindingDescr ) {
BindingDescr bind = (BindingDescr) b;
expression = bind.getVariable() + (bind.isUnification() ? " := " : " : ") + bind.getExpression();
} else if ( b instanceof ExprConstraintDescr ) {
ExprConstraintDescr descr = (ExprConstraintDescr) b;
expression = descr.getExpression();
isPositional = descr.getType() == ExprConstraintDescr.Type.POSITIONAL;
} else {
expression = b.getText();
}
ConstraintConnectiveDescr result = parseExpression( context,
patternDescr,
b,
expression );
if ( result == null ) {
return;
}
if ( result.getDescrs().size() == 1 && result.getDescrs().get( 0 ) instanceof BindingDescr ) {
// it is just a bind, so build it
buildRuleBindings( context,
patternDescr,
pattern,
(BindingDescr) result.getDescrs().get( 0 ) );
} else if ( isPositional ) {
processPositional( context,
patternDescr,
pattern,
(ExprConstraintDescr) b );
} else {
// need to build the actual constraint
build( context,
patternDescr,
pattern,
result );
}
}
}
@SuppressWarnings("unchecked")
private void processPositional( final RuleBuildContext context,
final PatternDescr patternDescr,
final Pattern pattern,
final ExprConstraintDescr descr ) {
if ( descr.getType() == ExprConstraintDescr.Type.POSITIONAL && pattern.getObjectType() instanceof ClassObjectType ) {
Class< ? > klazz = ((ClassObjectType) pattern.getObjectType()).getClassType();
TypeDeclaration tDecl = context.getPackageBuilder().getTypeDeclaration( klazz );
if ( tDecl == null ) {
context.getErrors().add( new DescrBuildError( context.getParentDescr(),
descr,
klazz,
"Unable to find @positional definitions for :" + klazz + "\n" ) );
return;
}
ClassDefinition clsDef = tDecl.getTypeClassDef();
if ( clsDef == null ) {
context.getErrors().add( new DescrBuildError( context.getParentDescr(),
descr,
null,
"Unable to find @positional field " + descr.getPosition() + " for class " + tDecl.getTypeName() + "\n" ) );
return;
}
FieldDefinition field = clsDef.getField( descr.getPosition() );
if ( field == null ) {
context.getErrors().add( new DescrBuildError( context.getParentDescr(),
descr,
null,
"Unable to find @positional field " + descr.getPosition() + " for class " + tDecl.getTypeName() + "\n" ) );
return;
}
// TODO: WTH is this??????
DRLLexer lex = new DRLLexer( new ANTLRStringStream( descr.getExpression() ) );
boolean isSimpleIdentifier = false;
try {
lex.mID();
isSimpleIdentifier = lex.getCharIndex() >= descr.getExpression().length();
} catch ( RecognitionException e ) {
}
if ( isSimpleIdentifier ) {
// create a binding
BindingDescr binder = new BindingDescr();
binder.setUnification( true );
binder.setExpression( field.getName() );
binder.setVariable( descr.getExpression() );
buildRuleBindings( context,
patternDescr,
pattern,
binder );
} else {
// create a constraint
build( context,
patternDescr,
pattern,
descr,
field.getName() + " == " + descr.getExpression() );
}
}
}
private void build( final RuleBuildContext context,
final PatternDescr patternDescr,
final Pattern pattern,
final BaseDescr original,
final String expr ) {
ConstraintConnectiveDescr result = parseExpression( context,
patternDescr,
original,
expr );
if ( result == null ) {
return;
}
result.copyLocation( original );
build( context,
patternDescr,
pattern,
result );
}
private void build( RuleBuildContext context,
PatternDescr patternDescr,
Pattern pattern,
ConstraintConnectiveDescr descr ) {
for ( BaseDescr d : descr.getDescrs() ) {
d.copyLocation( descr );
if ( d instanceof BindingDescr ) {
buildRuleBindings( context,
patternDescr,
pattern,
(BindingDescr) d );
continue;
}
boolean simple = false;
MVELDumper.MVELDumperContext mvelCtx = new MVELDumper.MVELDumperContext();
String expr = new MVELDumper().dump( d,
mvelCtx );
Map<String, OperatorDescr> aliases = mvelCtx.getAliases();
// create bindings
for ( BindingDescr bind : mvelCtx.getBindings() ) {
buildRuleBindings( context,
patternDescr,
pattern,
bind );
}
// check if it is an atomic expression
if ( processAtomicExpression( context,
pattern,
d,
expr,
aliases ) ) {
// it is an atomic expression
continue;
}
// check if it is a simple expression or not
RelationalExprDescr relDescr = d instanceof RelationalExprDescr ? (RelationalExprDescr) d : null;
simple = isSimpleExpr( relDescr );
if ( simple && // simple means also relDescr is != null
!ClassObjectType.Map_ObjectType.isAssignableFrom( pattern.getObjectType() ) &&
!ClassObjectType.Activation_ObjectType.isAssignableFrom( pattern.getObjectType() ) ) {
buildRelationalExpression( context,
pattern,
relDescr,
expr,
aliases );
} else {
// Either it's a complex expression, so do as predicate
// Or it's a Map and we have to treat it as a special case
createAndBuildPredicate( context,
pattern,
d,
expr,
aliases );
}
}
}
@SuppressWarnings("unchecked")
private void buildRelationalExpression( final RuleBuildContext context,
final Pattern pattern,
final RelationalExprDescr relDescr,
final String expr,
final Map<String, OperatorDescr> aliases ) {
String value1;
String value2;
boolean usesThisRef;
if ( relDescr.getRight() instanceof AtomicExprDescr ) {
AtomicExprDescr rdescr = ((AtomicExprDescr) relDescr.getRight());
value2 = rdescr.getExpression().trim();
usesThisRef = "this".equals( value2 ) || value2.startsWith( "this." );
} else {
BindingDescr rdescr = ((BindingDescr) relDescr.getRight());
value2 = rdescr.getExpression().trim();
usesThisRef = "this".equals( value2 ) || value2.startsWith( "this." );
}
if ( relDescr.getLeft() instanceof AtomicExprDescr ) {
AtomicExprDescr ldescr = (AtomicExprDescr) relDescr.getLeft();
value1 = ldescr.getExpression();
usesThisRef = usesThisRef || "this".equals( value1 ) || value1.startsWith( "this." );
} else {
value1 = ((BindingDescr) relDescr.getLeft()).getExpression();
usesThisRef = usesThisRef || "this".equals( value1 ) || value1.startsWith( "this." );
}
ExprBindings value1Expr = new ExprBindings();
setInputs( context,
value1Expr,
(pattern.getObjectType() instanceof ClassObjectType) ? ((ClassObjectType) pattern.getObjectType()).getClassType() : FactTemplate.class,
value1 );
ExprBindings value2Expr = new ExprBindings();
setInputs( context,
value2Expr,
(pattern.getObjectType() instanceof ClassObjectType) ? ((ClassObjectType) pattern.getObjectType()).getClassType() : FactTemplate.class,
value2 );
// build a predicate if it is a constant expression or at least has a constant on the left side
// or as a fallback when the building of a constraint fails
if ( (!usesThisRef && value1Expr.isConstant()) ||
!addConstraintToPattern( context, pattern, relDescr, expr, value1, value2, value2Expr.isConstant() )) {
createAndBuildPredicate( context, pattern, relDescr, expr, aliases );
}
}
private boolean addConstraintToPattern( final RuleBuildContext context,
final Pattern pattern,
final RelationalExprDescr relDescr,
String expr,
String value1,
String value2,
boolean isConstant ) {
int dotPos = value1.indexOf('.');
if (dotPos > 0) {
String part0 = value1.substring(0, dotPos).trim();
if ("this".equals( part0.trim() ) ) {
value1 = value1.substring(dotPos + 1);
} else if ( pattern.getDeclaration() != null && part0.equals( pattern.getDeclaration().getIdentifier() ) ) {
value1 = value1.substring(dotPos + 1);
expr = expr.substring(dotPos + 1);
}
}
final InternalReadAccessor extractor = getFieldReadAccessor( context, relDescr, pattern.getObjectType(), value1, null, false );
if ( extractor == null ) {
return false; // impossible to create extractor
}
ValueType vtype = extractor.getValueType();
String operator = relDescr.getOperator().trim();
LiteralRestrictionDescr restrictionDescr = buildLiteralRestrictionDescr(context, relDescr, value2, operator, isConstant);
if (restrictionDescr != null) {
FieldValue field = getFieldValue(context, vtype, restrictionDescr);
if (field != null) {
Constraint constraint = buildLiteralConstraint(context, vtype, field, expr, value1, operator, value2, extractor, restrictionDescr);
if (constraint != null) {
pattern.addConstraint(constraint);
return true;
}
}
}
Restriction restriction = null;
Declaration[] declarations = null;
Declaration declr = null;
if ( value2.indexOf( '(' ) < 0 && value2.indexOf( '.' ) < 0 && value2.indexOf( '[' ) < 0 ) {
declr = context.getDeclarationResolver().getDeclaration( context.getRule(), value2 );
if ( declr == null ) {
// trying to create implicit declaration
final Pattern thisPattern = (Pattern) context.getBuildStack().peek();
declr = this.createDeclarationObject( context,
value2,
thisPattern );
if ( declr == null ) {
// maybe it was a class literal ?
try {
final Class< ? > cls = context.getDialect().getTypeResolver().resolveType( value2 );
restrictionDescr = new LiteralRestrictionDescr( operator,
relDescr.isNegated(),
relDescr.getParameters(),
cls.getName(),
LiteralRestrictionDescr.TYPE_STRING ); // default type
restriction = buildLiteralRestriction( context,
extractor,
restrictionDescr,
getFieldValue(context, vtype, restrictionDescr),
vtype );
} catch ( ClassNotFoundException cnfe ) {
// we will later fallback to regular predicates, so don't raise error
// context.getErrors().add( new DescrBuildError( context.getParentDescr(),
// d,
// null,
// "Unable to return Declaration for identifier '" + rightValue + "'" ) );
return false;
}
}
}
}
if ( declr == null ) {
String[] parts = value2.split( "\\." );
if ( parts.length == 2 ) {
if ( "this".equals( parts[0].trim() ) ) {
declr = this.createDeclarationObject( context,
parts[1].trim(),
(Pattern) context.getBuildStack().peek() );
value2 = parts[1].trim();
} else {
declr = context.getDeclarationResolver().getDeclaration( context.getRule(),
parts[0].trim() );
// if a declaration exists, then it may be a variable direct property access
if ( declr != null ) {
if ( declr.isPatternDeclaration() ) {
// TODO: no need to extract inner declaration when using mvel constraint
declarations = new Declaration[] { declr };
declr = this.createDeclarationObject( context,
parts[1].trim(),
declr.getPattern() );
value2 = parts[1].trim();
} else {
// we will later fallback to regular predicates, so don't raise error
// context.getErrors().add( new DescrBuildError( context.getParentDescr(),
// relDescr,
// "",
// "Not possible to directly access the property '" + parts[1] + "' of declaration '" + parts[0] + "' since it is not a pattern" ) );
return false;
}
}
}
}
}
if ( declr != null ) {
Target right = getRightTarget( extractor );
Target left = (declr.isPatternDeclaration() && !(Date.class.isAssignableFrom( declr.getExtractor().getExtractToClass() ) || Number.class.isAssignableFrom( declr.getExtractor().getExtractToClass() ))) ? Target.HANDLE : Target.FACT;
final Evaluator evaluator = getEvaluator( context,
relDescr,
extractor.getValueType(),
operator,
relDescr.isNegated(),
relDescr.getParametersText(),
left,
right );
if ( evaluator == null ) {
return false;
}
restriction = new VariableRestriction( extractor,
declr,
evaluator );
if ( declr.getPattern().getObjectType().equals( new ClassObjectType( DroolsQuery.class ) ) && Operator.EQUAL.getOperatorString().equals( operator ) ) {
// declaration is query argument, so allow for unification.
restriction = new UnificationRestriction( (VariableRestriction) restriction );
}
}
if ( restriction == null ) {
Dialect dialect = context.getDialect();
if ( !value2.startsWith( "(" ) ) {
// it's not a traditional return value, so override the dialect
MVELDialect mvelDialect = (MVELDialect) context.getDialect( "mvel" );
context.setDialect( mvelDialect );
}
// execute it as a return value
restriction = buildRestriction( context,
(Pattern) context.getBuildStack().peek(),
extractor,
new ReturnValueRestrictionDescr( operator,
relDescr.isNegated(),
relDescr.getParametersText(),
value2 ) );
// fall back to original dialect
context.setDialect( dialect );
}
if ( restriction == null ) {
// something failed and an error should already have been reported
return false;
}
if (declr == null) {
ReturnValueRestriction returnValueRestriction = (ReturnValueRestriction)restriction;
Declaration[] requiredDeclarations = restriction.getRequiredDeclarations();
String[] requiredGlobals = returnValueRestriction.getRequiredGlobals();
declarations = new Declaration[(requiredDeclarations != null ? requiredDeclarations.length : 0) + (requiredGlobals != null ? requiredGlobals.length : 0)];
int i = 0;
if (requiredDeclarations != null) {
for (Declaration requiredDeclaration : requiredDeclarations)
declarations[i++] = requiredDeclaration;
}
if (requiredGlobals != null) {
for (String requiredGlobal : requiredGlobals)
declarations[i++] = context.getDeclarationResolver().getDeclaration(context.getRule(), requiredGlobal);
}
} else {
if (declarations == null) declarations = new Declaration[] { declr };
/*
else {
Declaration[] redefinedDeclaration = new Declaration[declarations.length+1];
for (int i = 0; i < declarations.length; i++) redefinedDeclaration[i] = declarations[i];
redefinedDeclaration[declarations.length] = declr;
declarations = redefinedDeclaration;
}
*/
}
pattern.addConstraint(buildVariableConstraint(context, expr, declarations, value1, operator, value2, extractor, restriction));
return true;
}
private LiteralRestrictionDescr buildLiteralRestrictionDescr(RuleBuildContext context,
RelationalExprDescr exprDescr,
String rightValue,
String operator,
boolean isRightLiteral) {
// is it a literal? Does not include enums
if ( isRightLiteral )
return new LiteralRestrictionDescr(operator, exprDescr.isNegated(), exprDescr.getParameters(), rightValue, LiteralRestrictionDescr.TYPE_STRING);
// is it an enum?
int dotPos = rightValue.lastIndexOf( '.' );
if ( dotPos >= 0 ) {
final String mainPart = rightValue.substring( 0,
dotPos );
String lastPart = rightValue.substring( dotPos + 1 );
try {
context.getDialect().getTypeResolver().resolveType( mainPart );
if ( lastPart.indexOf( '(' ) < 0 && lastPart.indexOf( '.' ) < 0 && lastPart.indexOf( '[' ) < 0 ) {
return new LiteralRestrictionDescr(operator, exprDescr.isNegated(), exprDescr.getParameters(), rightValue, LiteralRestrictionDescr.TYPE_STRING );
}
} catch ( ClassNotFoundException e ) {
// do nothing as this is just probing to see if it was a class, which we now know it isn't :)
}
}
return null;
}
private boolean processAtomicExpression( RuleBuildContext context,
Pattern pattern,
BaseDescr d,
String expr,
Map<String, OperatorDescr> aliases ) {
if ( d instanceof AtomicExprDescr ) {
Matcher m = evalRegexp.matcher( ((AtomicExprDescr) d).getExpression() );
if ( m.find() ) {
// MVELDumper already stripped the eval
// this will build the eval using the specified dialect
PredicateDescr pdescr = new PredicateDescr( expr );
pdescr.copyLocation( d );
buildEval( context,
pattern,
pdescr,
null,
aliases );
return true;
}
}
return false;
}
private boolean isSimpleExpr( final RelationalExprDescr relDescr ) {
boolean simple = false;
if ( relDescr != null ) {
if ( (relDescr.getLeft() instanceof AtomicExprDescr || relDescr.getLeft() instanceof BindingDescr) &&
(relDescr.getRight() instanceof AtomicExprDescr || relDescr.getRight() instanceof BindingDescr) ) {
simple = true;
}
}
return simple;
}
private void createAndBuildPredicate( RuleBuildContext context,
Pattern pattern,
BaseDescr base,
String expr,
Map<String, OperatorDescr> aliases ) {
Dialect dialect = context.getDialect();
MVELDialect mvelDialect = (MVELDialect) context.getDialect( "mvel" );
context.setDialect( mvelDialect );
PredicateDescr pdescr = new PredicateDescr( expr );
pdescr.copyLocation( base );
buildEval( context,
pattern,
pdescr,
null,
aliases );
// fall back to original dialect
context.setDialect( dialect );
}
private void setInputs( RuleBuildContext context,
ExprBindings descrBranch,
Class< ? > thisClass,
String expr ) {
MVELDialectRuntimeData data = (MVELDialectRuntimeData) context.getPkg().getDialectRuntimeRegistry().getDialectData( "mvel" );
ParserConfiguration conf = data.getParserConfiguration();
conf.setClassLoader( context.getPackageBuilder().getRootClassLoader() );
final ParserContext pctx = new ParserContext( conf );
pctx.setStrictTypeEnforcement( false );
pctx.setStrongTyping( false );
pctx.addInput( "this",
thisClass );
pctx.addInput( "empty",
boolean.class ); // overrides the mvel empty label
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;
MVEL.analysisCompile( expr,
pctx );
if ( !pctx.getInputs().isEmpty() ) {
for ( String v : pctx.getInputs().keySet() ) {
// in the following if, we need to check that the expr actually contains a reference
// to an "empty" property, or the if will evaluate to true even if it doesn't
if ( "this".equals( v ) || (PropertyTools.getFieldOrAccessor( thisClass,
v ) != null && expr.matches( "(^|.*\\W)empty($|\\W.*)" )) ) {
descrBranch.getFieldAccessors().add( v );
} else if ( "empty".equals( v ) ) {
// do nothing
} else if ( !context.getPkg().getGlobals().containsKey( v ) ) {
descrBranch.getRuleBindings().add( v );
} else {
descrBranch.getGlobalBindings().add( v );
}
}
}
}
public static class ExprBindings {
private Set<String> globalBindings;
private Set<String> ruleBindings;
private Set<String> fieldAccessors;
public ExprBindings() {
this.globalBindings = new HashSet<String>();
this.ruleBindings = new HashSet<String>();
this.fieldAccessors = new HashSet<String>();
}
public Set<String> getGlobalBindings() {
return globalBindings;
}
public Set<String> getRuleBindings() {
return ruleBindings;
}
public Set<String> getFieldAccessors() {
return fieldAccessors;
}
public boolean isConstant() {
return this.globalBindings.isEmpty() && this.ruleBindings.isEmpty() && this.fieldAccessors.size() <= 1; // field accessors might contain the "this" reference
}
}
/**
* @param container
* @param constraint
*/
private void setConstraintType( final Pattern container,
final MutableTypeConstraint constraint ) {
final Declaration[] declarations = constraint.getRequiredDeclarations();
boolean isAlphaConstraint = true;
for ( int i = 0; isAlphaConstraint && i < declarations.length; i++ ) {
if ( !declarations[i].isGlobal() && declarations[i].getPattern() != container ) {
isAlphaConstraint = false;
}
}
ConstraintType type = isAlphaConstraint ? ConstraintType.ALPHA : ConstraintType.BETA;
constraint.setType( type );
}
@SuppressWarnings("unchecked")
private void buildRuleBindings( final RuleBuildContext context,
final PatternDescr patternDescr,
final Pattern pattern,
final BindingDescr fieldBindingDescr ) {
if ( context.getDeclarationResolver().isDuplicated( context.getRule(),
fieldBindingDescr.getVariable() ) ) {
if ( fieldBindingDescr.isUnification() ) {
// rewrite existing bindings into == constraints, so it unifies
build( context,
patternDescr,
pattern,
fieldBindingDescr,
fieldBindingDescr.getExpression() + " == " + fieldBindingDescr.getVariable() );
return;
} else {
// This declaration already exists, so throw an Exception
context.getErrors().add( new DescrBuildError( context.getParentDescr(),
fieldBindingDescr,
null,
"Duplicate declaration for variable '" + fieldBindingDescr.getVariable() + "' in the rule '" + context.getRule().getName() + "'" ) );
}
}
Declaration declr = pattern.addDeclaration( fieldBindingDescr.getVariable() );
final InternalReadAccessor extractor = getFieldReadAccessor( context,
fieldBindingDescr,
pattern.getObjectType(),
fieldBindingDescr.getExpression(),
declr,
true );
declr.setReadAccessor( extractor );
}
@SuppressWarnings("unchecked")
private void buildEval( final RuleBuildContext context,
final Pattern pattern,
final PredicateDescr predicateDescr,
final AbstractCompositeConstraint container,
final Map<String, OperatorDescr> aliases ) {
Map<String, Class< ? >> declarations = getDeclarationsMap( predicateDescr,
context,
true );
Map<String, Class< ? >> globals = context.getPackageBuilder().getGlobals();
Map<String, EvaluatorWrapper> operators = new HashMap<String, EvaluatorWrapper>();
for ( Map.Entry<String, OperatorDescr> entry : aliases.entrySet() ) {
OperatorDescr op = entry.getValue();
String leftStr = op.getLeftString();
String rightStr = op.getRightString();
Declaration leftDecl = context.getDeclarationResolver().getDeclaration( context.getRule(),
leftStr );
if ( leftDecl == null && "this".equals( leftStr ) ) {
leftDecl = this.createDeclarationObject( context,
"this",
pattern );
}
Declaration rightDecl = context.getDeclarationResolver().getDeclaration( context.getRule(),
rightStr );
if ( rightDecl == null && "this".equals( rightStr ) ) {
rightDecl = this.createDeclarationObject( context,
"this",
pattern );
}
Target left = leftDecl != null && leftDecl.isPatternDeclaration() ? Target.HANDLE : Target.FACT;
Target right = rightDecl != null && rightDecl.isPatternDeclaration() ? Target.HANDLE : Target.FACT;
op.setLeftIsHandle( left == Target.HANDLE );
op.setRightIsHandle( right == Target.HANDLE );
Evaluator evaluator = getEvaluator( context,
predicateDescr,
ValueType.OBJECT_TYPE,
op.getOperator(),
false, // the rewrite takes care of negation
op.getParametersText(),
left,
right );
EvaluatorWrapper wrapper = new EvaluatorWrapper( evaluator,
left == Target.HANDLE ? leftDecl : null,
right == Target.HANDLE ? rightDecl : null );
operators.put( entry.getKey(),
wrapper );
}
Class< ? > thisClass = null;
if ( pattern.getObjectType() instanceof ClassObjectType ) {
thisClass = ((ClassObjectType) pattern.getObjectType()).getClassType();
}
final AnalysisResult analysis = context.getDialect().analyzeExpression( context,
predicateDescr,
predicateDescr.getContent(),
new BoundIdentifiers( declarations,
globals,
operators,
thisClass ) );
if ( analysis == null ) {
// something bad happened
return;
}
final BoundIdentifiers usedIdentifiers = analysis.getBoundIdentifiers();
final List tupleDeclarations = new ArrayList();
final List factDeclarations = new ArrayList();
for ( String id : usedIdentifiers.getDeclrClasses().keySet() ) {
final Declaration decl = context.getDeclarationResolver().getDeclaration( context.getRule(),
id );
if ( decl.getPattern() == pattern ) {
factDeclarations.add( decl );
} else {
tupleDeclarations.add( decl );
}
}
this.createImplicitBindings( context,
pattern,
analysis.getNotBoundedIdentifiers(),
analysis.getBoundIdentifiers(),
factDeclarations );
final Declaration[] previousDeclarations = (Declaration[]) tupleDeclarations.toArray( new Declaration[tupleDeclarations.size()] );
final Declaration[] localDeclarations = (Declaration[]) factDeclarations.toArray( new Declaration[factDeclarations.size()] );
final String[] requiredGlobals = usedIdentifiers.getGlobals().keySet().toArray( new String[usedIdentifiers.getGlobals().size()] );
final String[] requiredOperators = usedIdentifiers.getOperators().keySet().toArray( new String[usedIdentifiers.getOperators().size()] );
Arrays.sort( previousDeclarations,
SortDeclarations.instance );
Arrays.sort( localDeclarations,
SortDeclarations.instance );
final PredicateConstraint predicateConstraint = new PredicateConstraint( null,
previousDeclarations,
localDeclarations,
requiredGlobals,
requiredOperators );
if ( container == null ) {
pattern.addConstraint( predicateConstraint );
} else {
if ( predicateConstraint.getType().equals( Constraint.ConstraintType.UNKNOWN ) ) {
this.setConstraintType( pattern, predicateConstraint );
}
container.addConstraint( predicateConstraint );
}
final PredicateBuilder builder = context.getDialect().getPredicateBuilder();
builder.build( context,
usedIdentifiers,
previousDeclarations,
localDeclarations,
predicateConstraint,
predicateDescr,
analysis );
}
private static Map<String, Class< ? >> getDeclarationsMap( final BaseDescr baseDescr,
final RuleBuildContext context,
final boolean reportError ) {
Map<String, Class< ? >> declarations = new HashMap<String, Class< ? >>();
for ( Map.Entry<String, Declaration> entry : context.getDeclarationResolver().getDeclarations( context.getRule() ).entrySet() ) {
if ( entry.getValue().getExtractor() == null ) {
if ( reportError ) {
context.getErrors().add( new DescrBuildError( context.getParentDescr(),
baseDescr,
null,
"Field Reader does not exist for declaration '" + entry.getKey() + "' in '" + baseDescr + "' in the rule '" + context.getRule().getName() + "'" ) );
}
continue;
}
declarations.put( entry.getKey(),
entry.getValue().getExtractor().getExtractToClass() );
}
return declarations;
}
/**
* @param context
* @param pattern
* @param unboundIdentifiers
* @param factDeclarations
*/
private void createImplicitBindings( final RuleBuildContext context,
final Pattern pattern,
final Set<String> unboundIdentifiers,
final BoundIdentifiers boundIdentifiers,
final List factDeclarations ) {
for ( Iterator<String> it = unboundIdentifiers.iterator(); it.hasNext(); ) {
String identifier = it.next();
Declaration declaration = createDeclarationObject( context,
identifier,
pattern );
// the name may not be a local field, such as enums
// maybe should have a safer way to detect this, as other issues may cause null too
// that we would need to know about
if ( declaration != null ) {
factDeclarations.add( declaration );
// implicit bindings need to be added to "local" declarations, as they are nolonger unbound
if ( boundIdentifiers.getDeclarations() == null ) {
boundIdentifiers.setDeclarations( new HashMap<String, Declaration>() );
}
boundIdentifiers.getDeclarations().put( identifier,
declaration );
boundIdentifiers.getDeclrClasses().put( identifier,
declaration.getExtractor().getExtractToClass() );
it.remove();
}
}
}
/**
* Creates a declaration object for the field identified by the given identifier
* on the give pattern object
*
* @param context
* @param identifier
* @param pattern
* @return
*/
private Declaration createDeclarationObject( final RuleBuildContext context,
final String identifier,
final Pattern pattern ) {
return createDeclarationObject( context,
identifier,
identifier,
pattern );
}
private Declaration createDeclarationObject( final RuleBuildContext context,
final String identifier,
final String expr,
final Pattern pattern ) {
final BindingDescr implicitBinding = new BindingDescr( identifier,
expr );
final Declaration declaration = new Declaration( identifier,
null,
pattern,
true );
InternalReadAccessor extractor = getFieldReadAccessor( context,
implicitBinding,
pattern.getObjectType(),
implicitBinding.getExpression(),
declaration,
false );
if ( extractor == null ) {
return null;
}
declaration.setReadAccessor( extractor );
return declaration;
}
private FieldValue getFieldValue(RuleBuildContext context,
ValueType vtype,
LiteralRestrictionDescr literalRestrictionDescr) {
FieldValue field = null;
try {
String value = literalRestrictionDescr.getText().trim();
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;
MVELDialectRuntimeData data = (MVELDialectRuntimeData) context.getPkg().getDialectRuntimeRegistry().getDialectData( "mvel" );
ParserConfiguration pconf = data.getParserConfiguration();
ParserContext pctx = new ParserContext( pconf );
Object o = MVEL.executeExpression( MVEL.compileExpression( value,
pctx ) );
if ( o != null && vtype == null ) {
// was a compilation problem else where, so guess valuetype so we can continue
vtype = ValueType.determineValueType( o.getClass() );
}
field = FieldFactory.getFieldValue( o,
vtype,
context.getPackageBuilder().getDateFormats() );
} catch ( final Exception e ) {
// we will fallback to regular preducates, so don't raise an error
}
return field;
}
private ReturnValueRestriction buildRestriction( final RuleBuildContext context,
final Pattern pattern,
final InternalReadAccessor extractor,
final ReturnValueRestrictionDescr returnValueRestrictionDescr ) {
Map<String, Class< ? >> declarations = getDeclarationsMap( returnValueRestrictionDescr,
context,
true );
Class< ? > thisClass = null;
if ( pattern.getObjectType() instanceof ClassObjectType ) {
thisClass = ((ClassObjectType) pattern.getObjectType()).getClassType();
}
Map<String, Class< ? >> globals = context.getPackageBuilder().getGlobals();
AnalysisResult analysis = context.getDialect().analyzeExpression( context,
returnValueRestrictionDescr,
returnValueRestrictionDescr.getContent(),
new BoundIdentifiers( declarations,
globals,
null,
thisClass ) );
if ( analysis == null ) {
// something bad happened
return null;
}
final BoundIdentifiers usedIdentifiers = analysis.getBoundIdentifiers();
final List tupleDeclarations = new ArrayList();
final List factDeclarations = new ArrayList();
for ( String id : usedIdentifiers.getDeclrClasses().keySet() ) {
final Declaration decl = context.getDeclarationResolver().getDeclaration( context.getRule(),
id );
if ( decl.getPattern() == pattern ) {
factDeclarations.add( decl );
} else {
tupleDeclarations.add( decl );
}
}
this.createImplicitBindings( context,
pattern,
analysis.getNotBoundedIdentifiers(),
usedIdentifiers,
factDeclarations );
Target right = getRightTarget( extractor );
Target left = Target.FACT;
final Evaluator evaluator = getEvaluator( context,
returnValueRestrictionDescr,
extractor.getValueType(),
returnValueRestrictionDescr.getEvaluator(),
returnValueRestrictionDescr.isNegated(),
returnValueRestrictionDescr.getParameterText(),
left,
right );
if ( evaluator == null ) {
return null;
}
final Declaration[] previousDeclarations = (Declaration[]) tupleDeclarations.toArray( new Declaration[tupleDeclarations.size()] );
final Declaration[] localDeclarations = (Declaration[]) factDeclarations.toArray( new Declaration[factDeclarations.size()] );
Arrays.sort( previousDeclarations,
SortDeclarations.instance );
Arrays.sort( localDeclarations,
SortDeclarations.instance );
final String[] requiredGlobals = usedIdentifiers.getGlobals().keySet().toArray( new String[usedIdentifiers.getGlobals().size()] );
final ReturnValueRestriction returnValueRestriction = new ReturnValueRestriction( extractor,
previousDeclarations,
localDeclarations,
requiredGlobals,
evaluator );
final ReturnValueBuilder builder = context.getDialect().getReturnValueBuilder();
builder.build( context,
usedIdentifiers,
previousDeclarations,
localDeclarations,
returnValueRestriction,
returnValueRestrictionDescr,
analysis );
return returnValueRestriction;
}
public static void registerReadAccessor( final RuleBuildContext context,
final ObjectType objectType,
final String fieldName,
final AcceptsReadAccessor target ) {
if ( !ValueType.FACTTEMPLATE_TYPE.equals( objectType.getValueType() ) ) {
InternalReadAccessor reader = context.getPkg().getClassFieldAccessorStore().getReader( ((ClassObjectType) objectType).getClassName(),
fieldName,
target );
}
}
public static InternalReadAccessor getFieldReadAccessor( final RuleBuildContext context,
final BaseDescr descr,
final ObjectType objectType,
final String fieldName,
final AcceptsReadAccessor target,
final boolean reportError ) {
// reportError is needed as some times failure to build accessor is not a failure, just an indication that building is not possible so try something else.
InternalReadAccessor reader;
if ( ValueType.FACTTEMPLATE_TYPE.equals( objectType.getValueType() ) ) {
//@todo use accessor cache
final FactTemplate factTemplate = ((FactTemplateObjectType) objectType).getFactTemplate();
reader = new FactTemplateFieldExtractor( factTemplate,
factTemplate.getFieldTemplateIndex( fieldName ) );
if ( target != null ) {
target.setReadAccessor( reader );
}
} else if ( fieldName.indexOf( '.' ) > -1 || fieldName.indexOf( '[' ) > -1 || fieldName.indexOf( '(' ) > -1 ) {
// we need MVEL extractor for expressions
try {
Map<String, Class< ? >> declarations = getDeclarationsMap( descr,
context,
false );
Map<String, Class< ? >> globals = context.getPackageBuilder().getGlobals();
final AnalysisResult analysis = context.getDialect().analyzeExpression( context,
descr,
fieldName,
new BoundIdentifiers( declarations,
globals,
null,
((ClassObjectType) objectType).getClassType() ) );
if ( analysis == null ) {
// something bad happened
if ( reportError ) {
context.getErrors().add( new DescrBuildError( context.getParentDescr(),
descr,
null,
"Unable to analyze expression '" + fieldName + "'" ) );
}
return null;
}
final BoundIdentifiers usedIdentifiers = analysis.getBoundIdentifiers();
if ( !usedIdentifiers.getDeclrClasses().isEmpty() ) {
if ( reportError ) {
context.getErrors().add( new DescrBuildError( context.getParentDescr(),
descr,
null,
"Variables can not be used inside bindings. Variable " + usedIdentifiers.getDeclrClasses().keySet() + " is being used in binding '" + fieldName + "'" ) );
}
return null;
}
// final List<Declaration> tupleDeclarations = new ArrayList<Declaration>();
// final List<Declaration> factDeclarations = new ArrayList<Declaration>();
// for ( String id : usedIdentifiers.getDeclrClasses().keySet() ) {
// final Declaration decl = context.getDeclarationResolver().getDeclaration( context.getRule(),
// id );
// if ( decl.getPattern() == pattern ) {
// factDeclarations.add( decl );
// } else {
// tupleDeclarations.add( decl );
// }
// }
//
// final Declaration[] previousDeclarations = (Declaration[]) tupleDeclarations.toArray( new Declaration[tupleDeclarations.size()] );
// final Declaration[] localDeclarations = (Declaration[]) factDeclarations.toArray( new Declaration[factDeclarations.size()] );
// final String[] requiredGlobals = usedIdentifiers.getGlobals().keySet().toArray( new String[usedIdentifiers.getGlobals().size()] );
// final String[] requiredOperators = usedIdentifiers.getOperators().keySet().toArray( new String[usedIdentifiers.getOperators().size()] );
//
// Arrays.sort( previousDeclarations,
// SortDeclarations.instance );
// Arrays.sort( localDeclarations,
// SortDeclarations.instance );
reader = context.getPkg().getClassFieldAccessorStore().getMVELReader( context.getPkg().getName(),
((ClassObjectType) objectType).getClassName(),
fieldName,
context.isTypesafe() );
MVELDialectRuntimeData data = (MVELDialectRuntimeData) context.getPkg().getDialectRuntimeRegistry().getDialectData( "mvel" );
((MVELCompileable) reader).compile( data );
data.addCompileable( (MVELCompileable) reader );
} catch ( final Exception e ) {
if ( reportError ) {
copyErrorLocation( e,
descr );
context.getErrors().add( new DescrBuildError( context.getParentDescr(),
descr,
e,
"Unable to create reader for '" + fieldName + "':" + e.getMessage() ) );
}
// if there was an error, set the reader back to null
reader = null;
}
} else {
try {
reader = context.getPkg().getClassFieldAccessorStore().getReader( ((ClassObjectType) objectType).getClassName(),
fieldName,
target );
} catch ( final Exception e ) {
if ( reportError ) {
copyErrorLocation( e,
descr );
context.getErrors().add( new DescrBuildError( context.getParentDescr(),
descr,
e,
"Unable to create Field Extractor for '" + fieldName + "'" + e.getMessage() ) );
}
// if there was an error, set the reader back to null
reader = null;
}
}
return reader;
}
@SuppressWarnings("unchecked")
private ConstraintConnectiveDescr parseExpression( final RuleBuildContext context,
final PatternDescr patternDescr,
final BaseDescr original,
final String expression ) {
DrlExprParser parser = new DrlExprParser();
ConstraintConnectiveDescr result = parser.parse( expression );
result.copyLocation( original );
if ( parser.hasErrors() ) {
for ( DroolsParserException error : parser.getErrors() ) {
context.getErrors().add( new DescrBuildError( context.getParentDescr(),
patternDescr,
null,
"Unable to parser pattern expression:\n" + error.getMessage() ) );
}
return null;
}
return result;
}
}