package org.drools.lang;
/*
* Author Jayaram C S
*
* 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.
*/
import java.util.Iterator;
import org.drools.base.evaluators.Operator;
import org.drools.builder.conf.ProcessStringEscapesOption;
import org.drools.core.util.ReflectiveVisitor;
import org.drools.core.util.StringUtils;
import org.drools.lang.descr.FieldBindingDescr;
import org.drools.lang.descr.FieldConstraintDescr;
import org.drools.lang.descr.LiteralRestrictionDescr;
import org.drools.lang.descr.PredicateDescr;
import org.drools.lang.descr.QualifiedIdentifierRestrictionDescr;
import org.drools.lang.descr.RestrictionConnectiveDescr;
import org.drools.lang.descr.ReturnValueRestrictionDescr;
import org.drools.lang.descr.VariableRestrictionDescr;
import org.drools.rule.builder.RuleBuildContext;
/**
*
* @author <a href="mailto:jayaramcs@gmail.com">Author Jayaram C S</a>
*
*/
public class MVELDumper extends ReflectiveVisitor {
private StringBuilder mvelDump;
private boolean isDateField;
private static final String eol = System.getProperty( "line.separator" );
private String template;
private String fieldName;
private RuleBuildContext context;
public MVELDumper(RuleBuildContext context) {
this.context = context;
}
public MVELDumper() {
}
public String dump(FieldConstraintDescr fieldConstr) {
return this.dump( fieldConstr, false );
}
public String dump(FieldConstraintDescr fieldConstr, boolean isDateField ) {
mvelDump = new StringBuilder();
this.isDateField = isDateField;
this.visit( fieldConstr );
return mvelDump.toString();
}
public void visitFieldConstraintDescr(final FieldConstraintDescr descr) {
if ( !descr.getRestrictions().isEmpty() ) {
this.fieldName = descr.getFieldName();
mvelDump.append( processFieldConstraint( descr.getRestriction() ) );
}
}
public void visitVariableRestrictionDescr(final VariableRestrictionDescr descr) {
this.template = processRestriction( descr.getEvaluator(), descr.isNegated(), descr.getIdentifier() );
}
public void visitFieldBindingDescr(final FieldBindingDescr descr) {
// do nothing
}
public void visitLiteralRestrictionDescr(final LiteralRestrictionDescr descr) {
String text = descr.getText();
if ( text == null || descr.getType() == LiteralRestrictionDescr.TYPE_NULL ) {
text = "null";
} else if( descr.getType() == LiteralRestrictionDescr.TYPE_NUMBER ) {
try {
Integer.parseInt( text );
} catch ( final NumberFormatException e ) {
text = "\"" + text + "\"";
}
} else if( descr.getType() == LiteralRestrictionDescr.TYPE_STRING ) {
text = "\"" + text + "\"";
if( this.isDateField ) {
text = "org.drools.util.DateUtils.parseDate( "+text+" )";
}
}
this.template = processRestriction( descr.getEvaluator(), descr.isNegated(), text );
}
public void visitQualifiedIdentifierRestrictionDescr(final QualifiedIdentifierRestrictionDescr descr) {
this.template = processRestriction( descr.getEvaluator(), descr.isNegated(), descr.getText() );
}
public void visitRestrictionConnectiveDescr(final RestrictionConnectiveDescr descr) {
this.template = "( " + this.processFieldConstraint( descr ) + " )";
}
public void visitPredicateDescr(final PredicateDescr descr) {
this.template = "eval( " + descr.getContent() + " )";
}
public void visitReturnValueRestrictionDescr(final ReturnValueRestrictionDescr descr) {
this.template = processRestriction( descr.getEvaluator(), descr.isNegated(), "( "+descr.getContent().toString()+" )" );
}
private String processFieldConstraint(final RestrictionConnectiveDescr restriction) {
String descrString = "";
String connective = null;
if ( restriction.getConnective() == RestrictionConnectiveDescr.OR ) {
connective = " || ";
} else {
connective = " && ";
}
for ( final Iterator it = restriction.getRestrictions().iterator(); it.hasNext(); ) {
final Object temp = it.next();
visit( temp );
descrString += this.template;
if ( it.hasNext() ) {
descrString += connective;
}
}
return descrString;
}
private String processRestriction(String evaluator,
boolean isNegated,
String value) {
Operator op = Operator.determineOperator( evaluator, isNegated );
if( op == Operator.determineOperator( "memberOf", false ) ) {
evaluator = "contains";
return evaluatorPrefix( evaluator ) +
value + " " +
evaluator( evaluator ) + " " +
this.fieldName + evaluatorSufix( evaluator );
} else if(op == Operator.determineOperator( "memberOf", true )) {
evaluator = "not contains";
return evaluatorPrefix( evaluator ) +
value + " " +
evaluator( evaluator ) + " " +
this.fieldName + evaluatorSufix( evaluator );
} else if(op == Operator.determineOperator( "excludes", false ) ) {
evaluator = "not contains";
return evaluatorPrefix( evaluator ) +
this.fieldName + " " +
evaluator( evaluator ) + " " +
value + evaluatorSufix( evaluator );
} else if(op == Operator.determineOperator( "matches", false )) {
evaluator = "~=";
if(context != null && !context.getConfiguration().isProcessStringEscapes()) {
return evaluatorPrefix( evaluator ) +
this.fieldName + " " +
evaluator( evaluator ) + " " +
value.replaceAll( "\\\\", "\\\\\\\\" ) + evaluatorSufix( evaluator );
} else {
return evaluatorPrefix( evaluator ) +
this.fieldName + " " +
evaluator( evaluator ) + " " +
value +
evaluatorSufix( evaluator );
}
} else if(op == Operator.determineOperator( "matches", true )) {
evaluator = "not ~=";
if(context != null && !context.getConfiguration().isProcessStringEscapes()) {
return evaluatorPrefix( evaluator ) +
this.fieldName + " " +
evaluator( evaluator ) + " " +
value.replaceAll( "\\\\", "\\\\\\\\" ) + evaluatorSufix( evaluator );
} else {
return evaluatorPrefix( evaluator ) +
this.fieldName + " " +
evaluator( evaluator ) + " " +
value +
evaluatorSufix( evaluator );
}
}
return evaluatorPrefix( evaluator ) +
this.fieldName + " " +
evaluator( evaluator ) + " " +
value + evaluatorSufix( evaluator );
}
private String evaluatorPrefix(String evaluator) {
if ( evaluator.startsWith( "not" ) ) {
return "!( ";
}
return "";
}
private String evaluator(String evaluator) {
if ( evaluator.startsWith( "not" ) ) {
return evaluator.substring( 4 );
}
return evaluator;
}
private String evaluatorSufix(String evaluator) {
if ( evaluator.startsWith( "not" ) ) {
return " )";
}
return "";
}
}