/*
* 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 java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
import org.drools.base.ClassObjectType;
import org.drools.base.DroolsQuery;
import org.drools.base.FieldFactory;
import org.drools.base.ValueType;
import org.drools.base.evaluators.EvaluatorDefinition;
import org.drools.base.evaluators.EvaluatorDefinition.Target;
import org.drools.base.field.ObjectFieldImpl;
import org.drools.compiler.DescrBuildError;
import org.drools.compiler.Dialect;
import org.drools.core.util.StringUtils;
import org.drools.facttemplates.FactTemplate;
import org.drools.facttemplates.FactTemplateFieldExtractor;
import org.drools.facttemplates.FactTemplateObjectType;
import org.drools.lang.MVELDumper;
import org.drools.lang.descr.AndDescr;
import org.drools.lang.descr.BaseDescr;
import org.drools.lang.descr.BehaviorDescr;
import org.drools.lang.descr.FieldBindingDescr;
import org.drools.lang.descr.FieldConstraintDescr;
import org.drools.lang.descr.LiteralRestrictionDescr;
import org.drools.lang.descr.OrDescr;
import org.drools.lang.descr.PatternDescr;
import org.drools.lang.descr.PredicateDescr;
import org.drools.lang.descr.QualifiedIdentifierRestrictionDescr;
import org.drools.lang.descr.RestrictionConnectiveDescr;
import org.drools.lang.descr.RestrictionDescr;
import org.drools.lang.descr.ReturnValueRestrictionDescr;
import org.drools.lang.descr.SlidingWindowDescr;
import org.drools.lang.descr.VariableRestrictionDescr;
import org.drools.rule.AbstractCompositeConstraint;
import org.drools.rule.AbstractCompositeRestriction;
import org.drools.rule.AndCompositeRestriction;
import org.drools.rule.AndConstraint;
import org.drools.rule.Behavior;
import org.drools.rule.Declaration;
import org.drools.rule.LiteralConstraint;
import org.drools.rule.LiteralRestriction;
import org.drools.rule.MultiRestrictionFieldConstraint;
import org.drools.rule.MutableTypeConstraint;
import org.drools.rule.OrCompositeRestriction;
import org.drools.rule.OrConstraint;
import org.drools.rule.Pattern;
import org.drools.rule.PatternSource;
import org.drools.rule.PredicateConstraint;
import org.drools.rule.Query;
import org.drools.rule.ReturnValueConstraint;
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.UnificationRestriction;
import org.drools.rule.VariableConstraint;
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.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.spi.Constraint.ConstraintType;
import org.mvel2.ParserContext;
import org.mvel2.compiler.ExpressionCompiler;
/**
* A builder for patterns
*
* @author etirelli
*/
public class PatternBuilder
implements
RuleConditionBuilder {
public PatternBuilder() {
}
public RuleConditionElement build(RuleBuildContext context,
BaseDescr descr) {
return this.build( context,
descr,
null );
}
/**
* Build a pattern for the given descriptor in the current
* context and using the given utils object
*
* @param context
* @param utils
* @param patternDescr
* @return
*/
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() );
final boolean isEvent = context.getPkg().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 ) {
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();
return qeBuilder.build( context, descr, prefixPattern );
} else {
// 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 null;
}
}
Pattern pattern;
if ( patternDescr.getIdentifier() != null && !patternDescr.getIdentifier().equals( "" ) ) {
if ( context.getDeclarationResolver().isDuplicated( context.getRule(),
patternDescr.getIdentifier() ) ) {
// 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() + "'" ) );
}
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 ( 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 );
}
//context.getPkg().getClassFieldAccessorStore().get
// adding the newly created pattern to the build stack
// this is necessary in case of local declaration usage
context.getBuildStack().push( pattern );
for ( final Iterator it = patternDescr.getDescrs().iterator(); it.hasNext(); ) {
final Object object = it.next();
buildConstraint( context,
pattern,
object,
null );
}
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() );
pattern.setSource( source );
}
for ( BehaviorDescr behaviorDescr : patternDescr.getBehaviors() ) {
if( pattern.getObjectType().isEvent() ) {
if ( Behavior.BehaviorType.TIME_WINDOW.matches( behaviorDescr.getType() ) ) {
SlidingWindowDescr swd = (SlidingWindowDescr) behaviorDescr;
SlidingTimeWindow window = new SlidingTimeWindow( swd.getLength() );
pattern.addBehavior( window );
} else if ( Behavior.BehaviorType.LENGTH_WINDOW.matches( behaviorDescr.getType() ) ) {
SlidingWindowDescr swd = (SlidingWindowDescr) behaviorDescr;
SlidingLengthWindow window = new SlidingLengthWindow( (int) swd.getLength() );
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;
}
private void buildConstraint(final RuleBuildContext context,
final Pattern pattern,
final Object constraint,
final AbstractCompositeConstraint container) {
if ( constraint instanceof FieldBindingDescr ) {
build( context,
pattern,
(FieldBindingDescr) constraint );
} else if ( constraint instanceof FieldConstraintDescr ) {
build( context,
pattern,
(FieldConstraintDescr) constraint,
container );
} else if ( constraint instanceof PredicateDescr ) {
build( context,
pattern,
(PredicateDescr) constraint,
container );
} else if ( constraint instanceof AndDescr ) {
AndConstraint and = new AndConstraint();
for ( Iterator it = ((AndDescr) constraint).getDescrs().iterator(); it.hasNext(); ) {
this.buildConstraint( context,
pattern,
it.next(),
and );
}
if ( container == null ) {
pattern.addConstraint( and );
} else {
if ( and.getType().equals( Constraint.ConstraintType.UNKNOWN ) ) {
this.setConstraintType( pattern,
(MutableTypeConstraint) and );
}
container.addConstraint( and );
}
} else if ( constraint instanceof OrDescr ) {
OrConstraint or = new OrConstraint();
for ( Iterator it = ((OrDescr) constraint).getDescrs().iterator(); it.hasNext(); ) {
this.buildConstraint( context,
pattern,
it.next(),
or );
}
if ( container == null ) {
pattern.addConstraint( or );
} else {
if ( or.getType().equals( Constraint.ConstraintType.UNKNOWN ) ) {
this.setConstraintType( pattern,
(MutableTypeConstraint) or );
}
container.addConstraint( or );
}
} else {
context.getErrors().add( new DescrBuildError( context.getParentDescr(),
(BaseDescr) constraint,
null,
"This is a bug: unable to build constraint descriptor: '" + constraint + "' in rule '" + context.getRule().getName() + "'" ) );
}
}
private void build(final RuleBuildContext context,
final Pattern pattern,
final FieldConstraintDescr fieldConstraintDescr,
final AbstractCompositeConstraint container) {
String fieldName = fieldConstraintDescr.getFieldName();
if ( fieldName.indexOf( '[' ) > -1 ) {
rewriteToEval( context,
pattern,
fieldConstraintDescr,
container );
// after building the predicate, we are done, so return
return;
}
if ( fieldName.indexOf( '.' ) > -1 ) {
// we have a composite field name
String[] identifiers = fieldName.split( "\\." );
if ( identifiers.length == 2 && ((pattern.getDeclaration() != null && identifiers[0].equals( pattern.getDeclaration().getIdentifier() )) || ("this".equals( identifiers[0] ))) ) {
// we have a self reference, so, it is fine to do direct access
fieldName = identifiers[1];
} else {
rewriteToEval( context,
pattern,
fieldConstraintDescr,
container );
// after building the predicate, we are done, so return
return;
}
}
// if it is not a complex expression, just build a simple field constraint
final InternalReadAccessor extractor = getFieldReadAccessor( context,
fieldConstraintDescr,
pattern.getObjectType(),
fieldName,
null,
false );
if ( extractor == null ) {
if ( fieldConstraintDescr.getFieldName().startsWith( "this." ) ) {
// it may still be MVEL special syntax, like map key syntax, so try eval
rewriteToEval( context,
pattern,
fieldConstraintDescr,
container );
// after building the predicate, we are done, so return
return;
} else {
context.getErrors().add( new DescrBuildError( context.getParentDescr(),
fieldConstraintDescr,
null,
"Unable to create Field Extractor for '" + fieldName + "' of '" + pattern.getObjectType().toString() + "' in rule '" + context.getRule().getName() + "'" ) );
return;
}
}
Restriction restriction = createRestriction( context,
pattern,
fieldConstraintDescr,
fieldConstraintDescr.getRestriction(),
extractor );
if ( restriction == null ) {
// error was already logged during restriction creation failure
return;
}
Constraint constraint = null;
if ( restriction instanceof AbstractCompositeRestriction ) {
constraint = new MultiRestrictionFieldConstraint( extractor,
restriction );
} else if ( restriction instanceof LiteralRestriction ) {
constraint = new LiteralConstraint( extractor,
(LiteralRestriction) restriction );
registerReadAccessor( context,
pattern.getObjectType(),
fieldName,
(LiteralConstraint) constraint );
registerReadAccessor( context,
pattern.getObjectType(),
fieldName,
(LiteralRestriction) restriction );
} else if ( restriction instanceof VariableRestriction || restriction instanceof UnificationRestriction ) {
constraint = new VariableConstraint( extractor,
restriction );
registerReadAccessor( context,
pattern.getObjectType(),
fieldName,
(AcceptsReadAccessor) restriction );
registerReadAccessor( context,
pattern.getObjectType(),
fieldName,
(AcceptsReadAccessor) restriction );
} else if ( restriction instanceof ReturnValueRestriction ) {
constraint = new ReturnValueConstraint( extractor,
(ReturnValueRestriction) restriction );
registerReadAccessor( context,
pattern.getObjectType(),
fieldName,
(ReturnValueConstraint) constraint );
registerReadAccessor( context,
pattern.getObjectType(),
fieldName,
(ReturnValueRestriction) restriction );
} else {
context.getErrors().add( new DescrBuildError( context.getParentDescr(),
fieldConstraintDescr,
null,
"This is a bug: Unkown restriction type '" + restriction.getClass() + "' for pattern '" + pattern.getObjectType().toString() + "' in rule '" + context.getRule().getName() + "'" ) );
}
if ( container == null ) {
pattern.addConstraint( constraint );
} else {
if ( constraint.getType().equals( Constraint.ConstraintType.UNKNOWN ) ) {
this.setConstraintType( pattern,
(MutableTypeConstraint) constraint );
}
container.addConstraint( constraint );
}
}
/**
* @param pattern
* @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 );
}
private void rewriteToEval(final RuleBuildContext context,
final Pattern pattern,
final FieldConstraintDescr fieldConstraintDescr,
final AbstractCompositeConstraint container) {
// it is a complex expression, so we need to turn it into an MVEL predicate
Dialect dialect = context.getDialect();
// switch to MVEL dialect
MVELDialect mvelDialect = (MVELDialect) context.getDialect( "mvel" );
boolean strictMode = mvelDialect.isStrictMode();
mvelDialect.setStrictMode( false );
context.setDialect( mvelDialect );
// analyze field type:
Class resultType = getFieldReturnType( pattern,
fieldConstraintDescr );
PredicateDescr predicateDescr = new PredicateDescr();
MVELDumper dumper = new MVELDumper(context);
predicateDescr.setContent( dumper.dump( fieldConstraintDescr,
Date.class.isAssignableFrom( resultType ) ) );
build( context,
pattern,
predicateDescr,
container );
mvelDialect.setStrictMode( strictMode );
// fall back to original dialect
context.setDialect( dialect );
}
/**
* @param pattern
* @param fieldConstraintDescr
* @return
*/
private Class getFieldReturnType(final Pattern pattern,
final FieldConstraintDescr fieldConstraintDescr) {
String dummyField = "__DUMMY__";
String dummyExpr = dummyField + "." + fieldConstraintDescr.getFieldName();
ExpressionCompiler compiler = new ExpressionCompiler( dummyExpr );
ParserContext mvelcontext = new ParserContext();
mvelcontext.addInput( dummyField,
((ClassObjectType) pattern.getObjectType()).getClassType() );
compiler.compile( mvelcontext );
Class resultType = compiler.getReturnType();
return resultType;
}
private Restriction createRestriction(final RuleBuildContext context,
final Pattern pattern,
final FieldConstraintDescr fieldConstraintDescr,
final RestrictionConnectiveDescr top,
final InternalReadAccessor extractor) {
Restriction[] restrictions = new Restriction[top.getRestrictions().size()];
int index = 0;
for ( Iterator it = top.getRestrictions().iterator(); it.hasNext(); ) {
RestrictionDescr restrictionDescr = (RestrictionDescr) it.next();
if ( restrictionDescr instanceof RestrictionConnectiveDescr ) {
restrictions[index++] = this.createRestriction( context,
pattern,
fieldConstraintDescr,
(RestrictionConnectiveDescr) restrictionDescr,
extractor );
} else {
restrictions[index] = buildRestriction( context,
pattern,
extractor,
fieldConstraintDescr,
restrictionDescr );
if ( restrictions[index] == null ) {
context.getErrors().add( new DescrBuildError( context.getParentDescr(),
fieldConstraintDescr,
null,
"Unable to create restriction '" + restrictionDescr.toString() + "' for field '" + fieldConstraintDescr.getFieldName() + "' in the rule '" + context.getRule().getName() + "'" ) );
}
index++;
}
}
if ( restrictions.length > 1 ) {
AbstractCompositeRestriction composite = null;
if ( top.getConnective() == RestrictionConnectiveDescr.AND ) {
composite = new AndCompositeRestriction( restrictions );
} else if ( top.getConnective() == RestrictionConnectiveDescr.OR ) {
composite = new OrCompositeRestriction( restrictions );
} else {
context.getErrors().add( new DescrBuildError( context.getParentDescr(),
fieldConstraintDescr,
null,
"This is a bug: Impossible to create a composite restriction for connective: " + top.getConnective() + "' for field '" + fieldConstraintDescr.getFieldName() + "' in the rule '"
+ context.getRule().getName() + "'" ) );
}
return composite;
} else if ( restrictions.length == 1 ) {
return restrictions[0];
}
context.getErrors().add( new DescrBuildError( context.getParentDescr(),
fieldConstraintDescr,
null,
"This is a bug: trying to create a restriction for an empty restriction list for field '" + fieldConstraintDescr.getFieldName() + "' in the rule '" + context.getRule().getName() + "'" ) );
return null;
}
private void build(final RuleBuildContext context,
final Pattern pattern,
final FieldBindingDescr fieldBindingDescr) {
if ( context.getDeclarationResolver().isDuplicated( context.getRule(),
fieldBindingDescr.getIdentifier() ) ) {
// This declaration already exists, so throw an Exception
context.getErrors().add( new DescrBuildError( context.getParentDescr(),
fieldBindingDescr,
null,
"Duplicate declaration for variable '" + fieldBindingDescr.getIdentifier() + "' in the rule '" + context.getRule().getName() + "'" ) );
return;
}
Declaration declr = pattern.addDeclaration( fieldBindingDescr.getIdentifier() );
final InternalReadAccessor extractor = getFieldReadAccessor( context,
fieldBindingDescr,
pattern.getObjectType(),
fieldBindingDescr.getFieldName(),
declr,
true );
}
@SuppressWarnings("unchecked")
private void build(final RuleBuildContext context,
final Pattern pattern,
final PredicateDescr predicateDescr,
final AbstractCompositeConstraint container) {
Map<String, Class< ? >> declarations = getDeclarationsMap( predicateDescr, context );
Map<String, Class< ? >> globals = context.getPackageBuilder().getGlobals();
final Dialect.AnalysisResult analysis = context.getDialect().analyzeExpression( context,
predicateDescr,
predicateDescr.getContent(),
new Map[]{declarations, globals} );
if ( analysis == null ) {
// something bad happened
return;
}
// this will return an array with 2 lists
// where first list is from rule local variables
// second list is from global variables
final List[] usedIdentifiers = analysis.getBoundIdentifiers();
final List tupleDeclarations = new ArrayList();
final List factDeclarations = new ArrayList();
for ( int i = 0, size = usedIdentifiers[0].size(); i < size; i++ ) {
final Declaration decl = context.getDeclarationResolver().getDeclaration( context.getRule(),
(String) usedIdentifiers[0].get( i ) );
if ( decl.getPattern() == pattern ) {
factDeclarations.add( decl );
} else {
tupleDeclarations.add( decl );
}
}
this.createImplicitBindings( context,
pattern,
analysis.getNotBoundedIdentifiers(),
factDeclarations );
final Declaration[] previousDeclarations = (Declaration[]) tupleDeclarations.toArray( new Declaration[tupleDeclarations.size()] );
final Declaration[] localDeclarations = (Declaration[]) factDeclarations.toArray( new Declaration[factDeclarations.size()] );
final String[] requiredGlobals = (String[]) usedIdentifiers[1].toArray( new String[usedIdentifiers[1].size()] );
final PredicateConstraint predicateConstraint = new PredicateConstraint( null,
previousDeclarations,
localDeclarations,
requiredGlobals );
if ( container == null ) {
pattern.addConstraint( predicateConstraint );
} else {
if ( predicateConstraint.getType().equals( Constraint.ConstraintType.UNKNOWN ) ) {
this.setConstraintType( pattern,
(MutableTypeConstraint) predicateConstraint );
}
container.addConstraint( predicateConstraint );
}
final PredicateBuilder builder = context.getDialect().getPredicateBuilder();
builder.build( context,
usedIdentifiers,
previousDeclarations,
localDeclarations,
predicateConstraint,
predicateDescr );
}
private Map<String, Class< ? >> getDeclarationsMap(final BaseDescr baseDescr, final RuleBuildContext context) {
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 ) {
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 utils
* @param pattern
* @param usedIdentifiers
* @param NOT_BOUND_INDEX
* @param factDeclarations
*/
private void createImplicitBindings(final RuleBuildContext context,
final Pattern pattern,
final List unboundIdentifiers,
final List factDeclarations) {
// the following will create the implicit bindings
for ( int i = 0, size = unboundIdentifiers.size(); i < size; i++ ) {
final String identifier = (String) unboundIdentifiers.get( i );
Declaration declaration = createDeclarationObject( context,
identifier,
pattern );
if ( declaration != null ) {
factDeclarations.add( declaration );
}
}
}
/**
* 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) {
final FieldBindingDescr implicitBinding = new FieldBindingDescr( identifier,
identifier );
final Declaration declaration = new Declaration( identifier,
pattern );
final InternalReadAccessor extractor = getFieldReadAccessor( context,
implicitBinding,
pattern.getObjectType(),
implicitBinding.getFieldName(),
declaration,
false );
if ( extractor == null ) {
return null;
}
return declaration;
}
private Restriction buildRestriction(final RuleBuildContext context,
final Pattern pattern,
final InternalReadAccessor extractor,
final FieldConstraintDescr fieldConstraintDescr,
final RestrictionDescr restrictionDescr) {
Restriction restriction = null;
if ( restrictionDescr instanceof LiteralRestrictionDescr ) {
restriction = buildRestriction( context,
extractor,
fieldConstraintDescr,
(LiteralRestrictionDescr) restrictionDescr );
} else if ( restrictionDescr instanceof QualifiedIdentifierRestrictionDescr ) {
restriction = buildRestriction( context,
extractor,
fieldConstraintDescr,
(QualifiedIdentifierRestrictionDescr) restrictionDescr );
} else if ( restrictionDescr instanceof VariableRestrictionDescr ) {
restriction = buildRestriction( context,
extractor,
fieldConstraintDescr,
(VariableRestrictionDescr) restrictionDescr );
} else if ( restrictionDescr instanceof ReturnValueRestrictionDescr ) {
restriction = buildRestriction( context,
pattern,
extractor,
fieldConstraintDescr,
(ReturnValueRestrictionDescr) restrictionDescr );
}
return restriction;
}
private Restriction buildRestriction(final RuleBuildContext context,
final InternalReadAccessor extractor,
final FieldConstraintDescr fieldConstraintDescr,
final VariableRestrictionDescr variableRestrictionDescr) {
if ( variableRestrictionDescr.getIdentifier() == null || variableRestrictionDescr.getIdentifier().equals( "" ) ) {
context.getErrors().add( new DescrBuildError( context.getParentDescr(),
variableRestrictionDescr,
null,
"Identifier not defined for binding field '" + fieldConstraintDescr.getFieldName() + "'" ) );
return null;
}
Declaration declaration = context.getDeclarationResolver().getDeclaration( context.getRule(),
variableRestrictionDescr.getIdentifier() );
if ( declaration == null ) {
// trying to create implicit declaration
final Pattern thisPattern = (Pattern) context.getBuildStack().peek();
final Declaration implicit = this.createDeclarationObject( context,
variableRestrictionDescr.getIdentifier(),
thisPattern );
if ( implicit != null ) {
declaration = implicit;
} else {
context.getErrors().add( new DescrBuildError( context.getParentDescr(),
variableRestrictionDescr,
null,
"Unable to return Declaration for identifier '" + variableRestrictionDescr.getIdentifier() + "'" ) );
return null;
}
}
Target right = getRightTarget( extractor );
Target left = (declaration.isPatternDeclaration() && !(Date.class.isAssignableFrom( declaration.getExtractor().getExtractToClass() ) || Number.class.isAssignableFrom( declaration.getExtractor().getExtractToClass() ))) ? Target.HANDLE : Target.FACT;
final Evaluator evaluator = getEvaluator( context,
variableRestrictionDescr,
extractor.getValueType(),
variableRestrictionDescr.getEvaluator(),
variableRestrictionDescr.isNegated(),
variableRestrictionDescr.getParameterText(),
left,
right );
if ( evaluator == null ) {
return null;
}
Restriction restriction = new VariableRestriction( extractor,
declaration,
evaluator );
// TODO: FIXME: Implement proper support for Unifications
// if ( declaration.getPattern().getObjectType().equals( new ClassObjectType( DroolsQuery.class ) ) ) {
// // declaration is query argument, so allow for unification.
// restriction = new UnificationRestriction( ( VariableRestriction ) restriction );
// }
return restriction;
}
private LiteralRestriction buildRestriction(final RuleBuildContext context,
final InternalReadAccessor extractor,
final FieldConstraintDescr fieldConstraintDescr,
final LiteralRestrictionDescr literalRestrictionDescr) {
FieldValue field = null;
try {
Object value = literalRestrictionDescr.getValue();
if ( literalRestrictionDescr.getType() == LiteralRestrictionDescr.TYPE_STRING && context.getConfiguration().isProcessStringEscapes() ) {
value = StringUtils.unescapeJava( (String) value );
}
field = FieldFactory.getFieldValue( value,
extractor.getValueType(),
context.getPackageBuilder().getDateFormats() );
} catch ( final Exception e ) {
context.getErrors().add( new DescrBuildError( context.getParentDescr(),
literalRestrictionDescr,
e,
"Unable to create a Field value of type '" + extractor.getValueType() + "' and value '" + literalRestrictionDescr.getText() + "'" ) );
}
if ( field == null ) {
return null;
}
Target right = getRightTarget( extractor );
Target left = Target.FACT;
final Evaluator evaluator = getEvaluator( context,
literalRestrictionDescr,
extractor.getValueType(),
literalRestrictionDescr.getEvaluator(),
literalRestrictionDescr.isNegated(),
literalRestrictionDescr.getParameterText(),
left,
right );
if ( evaluator == null ) {
return null;
}
return new LiteralRestriction( field,
evaluator,
extractor );
}
private Restriction buildRestriction(final RuleBuildContext context,
final InternalReadAccessor extractor,
final FieldConstraintDescr fieldConstraintDescr,
final QualifiedIdentifierRestrictionDescr qiRestrictionDescr) {
FieldValue field = null;
final String[] parts = qiRestrictionDescr.getText().split( "\\." );
// if only 2 parts, it may be a composed direct property access
if ( parts.length == 2 ) {
Declaration implicit = null;
if ( "this".equals( parts[0] ) ) {
implicit = this.createDeclarationObject( context,
parts[1],
(Pattern) context.getBuildStack().peek() );
} else {
final Declaration decl = context.getDeclarationResolver().getDeclaration( context.getRule(),
parts[0] );
// if a declaration exists, then it may be a variable direct property access, not an enum
if ( decl != null ) {
if ( decl.isPatternDeclaration() ) {
implicit = this.createDeclarationObject( context,
parts[1],
decl.getPattern() );
} else {
context.getErrors().add( new DescrBuildError( context.getParentDescr(),
qiRestrictionDescr,
"",
"Not possible to directly access the property '" + parts[1] + "' of declaration '" + parts[0] + "' since it is not a pattern" ) );
return null;
}
}
}
if ( implicit != null ) {
Target right = getRightTarget( extractor );
Target left = (implicit.isPatternDeclaration() && !(Date.class.isAssignableFrom( implicit.getExtractor().getExtractToClass() ) || Number.class.isAssignableFrom( implicit.getExtractor().getExtractToClass() ))) ? Target.HANDLE : Target.FACT;
final Evaluator evaluator = getEvaluator( context,
qiRestrictionDescr,
extractor.getValueType(),
qiRestrictionDescr.getEvaluator(),
qiRestrictionDescr.isNegated(),
qiRestrictionDescr.getParameterText(),
left,
right );
if ( evaluator == null ) {
return null;
}
return new VariableRestriction( extractor,
implicit,
evaluator );
}
}
final int lastDot = qiRestrictionDescr.getText().lastIndexOf( '.' );
final String className = qiRestrictionDescr.getText().substring( 0,
lastDot );
final String fieldName = qiRestrictionDescr.getText().substring( lastDot + 1 );
try {
final Class staticClass = context.getDialect().getTypeResolver().resolveType( className );
field = FieldFactory.getFieldValue( staticClass.getField( fieldName ).get( null ),
extractor.getValueType(),
context.getPackageBuilder().getDateFormats() );
if ( field.isObjectField() ) {
((ObjectFieldImpl) field).setEnum( true );
((ObjectFieldImpl) field).setEnumName( staticClass.getName() );
((ObjectFieldImpl) field).setFieldName( fieldName );
}
} catch ( final ClassNotFoundException e ) {
// nothing to do, as it is not a class name with static field
} catch ( final Exception e ) {
context.getErrors().add( new DescrBuildError( context.getParentDescr(),
qiRestrictionDescr,
e,
"Unable to create a Field value of type '" + extractor.getValueType() + "' and value '" + qiRestrictionDescr.getText() + "'" ) );
}
if ( field == null ) {
return null;
}
Target right = getRightTarget( extractor );
Target left = Target.FACT;
final Evaluator evaluator = getEvaluator( context,
qiRestrictionDescr,
extractor.getValueType(),
qiRestrictionDescr.getEvaluator(),
qiRestrictionDescr.isNegated(),
qiRestrictionDescr.getParameterText(),
left,
right );
if ( evaluator == null ) {
return null;
}
return new LiteralRestriction( field,
evaluator,
extractor );
}
private Target getRightTarget(final InternalReadAccessor extractor) {
Target right = (extractor.isSelfReference() && !(Date.class.isAssignableFrom( extractor.getExtractToClass() ) || Number.class.isAssignableFrom( extractor.getExtractToClass() ))) ? Target.HANDLE : Target.FACT;
return right;
}
private ReturnValueRestriction buildRestriction(final RuleBuildContext context,
final Pattern pattern,
final InternalReadAccessor extractor,
final FieldConstraintDescr fieldConstraintDescr,
final ReturnValueRestrictionDescr returnValueRestrictionDescr) {
Map<String, Class< ? >> declarations = getDeclarationsMap( returnValueRestrictionDescr, context );
Map<String, Class< ? >> globals = context.getPackageBuilder().getGlobals();
Dialect.AnalysisResult analysis = context.getDialect().analyzeExpression( context,
returnValueRestrictionDescr,
returnValueRestrictionDescr.getContent(),
new Map[]{declarations, globals} );
final List[] usedIdentifiers = analysis.getBoundIdentifiers();
final List tupleDeclarations = new ArrayList();
final List factDeclarations = new ArrayList();
for ( int i = 0, size = usedIdentifiers[0].size(); i < size; i++ ) {
final Declaration declaration = context.getDeclarationResolver().getDeclaration( context.getRule(),
(String) usedIdentifiers[0].get( i ) );
if ( declaration.getPattern() == pattern ) {
factDeclarations.add( declaration );
} else {
tupleDeclarations.add( declaration );
}
}
createImplicitBindings( context,
pattern,
analysis.getNotBoundedIdentifiers(),
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()] );
final String[] requiredGlobals = (String[]) usedIdentifiers[1].toArray( new String[usedIdentifiers[1].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 );
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) {
InternalReadAccessor reader = null;
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 {
try {
reader = context.getPkg().getClassFieldAccessorStore().getReader( ((ClassObjectType) objectType).getClassName(),
fieldName,
target );
} catch ( final Exception e ) {
if ( reportError ) {
context.getErrors().add( new DescrBuildError( context.getParentDescr(),
descr,
e,
"Unable to create Field Extractor for '" + fieldName + "'" ) );
}
}
}
return reader;
}
private Evaluator getEvaluator(final RuleBuildContext context,
final BaseDescr descr,
final ValueType valueType,
final String evaluatorString,
final boolean isNegated,
final String parameterText,
final Target left,
final Target right) {
final EvaluatorDefinition def = context.getConfiguration().getEvaluatorRegistry().getEvaluatorDefinition( evaluatorString );
if ( def == null ) {
context.getErrors().add( new DescrBuildError( context.getParentDescr(),
descr,
null,
"Unable to determine the Evaluator for ID '" + evaluatorString + "'" ) );
return null;
}
final Evaluator evaluator = def.getEvaluator( valueType,
evaluatorString,
isNegated,
parameterText,
left,
right );
if ( evaluator == null ) {
context.getErrors().add( new DescrBuildError( context.getParentDescr(),
descr,
null,
"Evaluator '" + (isNegated ? "not " : "") + evaluatorString + "' does not support type '" + valueType ) );
}
return evaluator;
}
}