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* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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
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*******************************************************************************/
package org.ofbiz.base.util.string;
import static de.odysseus.el.tree.impl.Scanner.Symbol.END_EVAL;
import static de.odysseus.el.tree.impl.Scanner.Symbol.FLOAT;
import static de.odysseus.el.tree.impl.Scanner.Symbol.START_EVAL_DEFERRED;
import static de.odysseus.el.tree.impl.Scanner.Symbol.START_EVAL_DYNAMIC;
import javax.el.ELContext;
import javax.el.ELException;
import javax.el.ExpressionFactory;
import javax.el.PropertyNotFoundException;
import de.odysseus.el.ExpressionFactoryImpl;
import de.odysseus.el.misc.LocalMessages;
import de.odysseus.el.tree.Bindings;
import de.odysseus.el.tree.Tree;
import de.odysseus.el.tree.TreeStore;
import de.odysseus.el.tree.impl.Builder;
import de.odysseus.el.tree.impl.Cache;
import de.odysseus.el.tree.impl.Parser;
import de.odysseus.el.tree.impl.Parser.ParseException;
import de.odysseus.el.tree.impl.Scanner.ScanException;
import de.odysseus.el.tree.impl.Scanner.Symbol;
import de.odysseus.el.tree.impl.ast.AstBracket;
import de.odysseus.el.tree.impl.ast.AstDot;
import de.odysseus.el.tree.impl.ast.AstEval;
import de.odysseus.el.tree.impl.ast.AstIdentifier;
import de.odysseus.el.tree.impl.ast.AstNode;
import org.ofbiz.base.util.Debug;
/** A facade class used to connect the OFBiz framework to the JUEL library.
*<p>The Unified Expression Language specification doesn't allow assignment of
* values to non-existent variables (auto-vivify) - but the OFBiz scripting
* languages do. This class modifies the JUEL library behavior to enable
* auto-vivify.</p>
*/
public class JuelConnector {
protected static final String module = JuelConnector.class.getName();
/** Returns an <code>ExpressionFactory</code> instance.
* @return A customized <code>ExpressionFactory</code> instance
*/
public static ExpressionFactory newExpressionFactory() {
return new ExpressionFactoryImpl(new TreeStore(new ExtendedBuilder(), new Cache(1000)));
}
/** Custom <code>AstBracket</code> class that implements
* <code>List</code> or <code>Map</code> auto-vivify.
*/
public static class ExtendedAstBracket extends AstBracket {
public ExtendedAstBracket(AstNode base, AstNode property, boolean lvalue, boolean strict) {
super(base, property, lvalue, strict);
}
@Override
public void setValue(Bindings bindings, ELContext context, Object value) throws ELException {
if (!lvalue) {
throw new ELException(LocalMessages.get("error.value.set.rvalue"));
}
Object base = null;
try {
base = prefix.eval(bindings, context);
} catch (Exception e) {}
Object property = getProperty(bindings, context);
if (property == null && strict) {
throw new PropertyNotFoundException(LocalMessages.get("error.property.property.notfound", "null", base));
}
if (base == null) {
base = UelUtil.autoVivifyListOrMap(property);
if (Debug.verboseOn()) {
Debug.logVerbose("ExtendedAstBracket.setValue auto-vivify base: " + base + ", property = " + property, module);
}
prefix.setValue(bindings, context, base);
}
context.getELResolver().setValue(context, base, property, value);
if (!context.isPropertyResolved()) {
throw new PropertyNotFoundException(LocalMessages.get("error.property.property.notfound", property, base));
}
}
}
/** Custom <code>AstDot</code> class that implements
* <code>List</code> or <code>Map</code> auto-vivify.
*/
public static class ExtendedAstDot extends AstDot {
public ExtendedAstDot(AstNode base, String property, boolean lvalue) {
super(base, property, lvalue);
}
@Override
public void setValue(Bindings bindings, ELContext context, Object value) throws ELException {
if (!lvalue) {
throw new ELException(LocalMessages.get("error.value.set.rvalue"));
}
Object base = null;
try {
base = prefix.eval(bindings, context);
} catch (Exception e) {}
Object property = getProperty(bindings, context);
if (property == null && strict) {
throw new PropertyNotFoundException(LocalMessages.get("error.property.property.notfound", "null", base));
}
if (base == null) {
base = UelUtil.autoVivifyListOrMap(property);
if (Debug.verboseOn()) {
Debug.logVerbose("ExtendedAstDot.setValue auto-vivify base: " + base + ", property = " + property, module);
}
prefix.setValue(bindings, context, base);
}
context.getELResolver().setValue(context, base, property, value);
if (!context.isPropertyResolved()) {
throw new PropertyNotFoundException(LocalMessages.get("error.property.property.notfound", property, base));
}
}
}
/** Custom <code>Parser</code> class needed to implement auto-vivify. */
protected static class ExtendedParser extends Parser {
public ExtendedParser(Builder context, String input) {
super(context, input);
}
@Override
protected AstEval eval(boolean required, boolean deferred) throws ScanException, ParseException {
AstEval v = null;
Symbol start_eval = deferred ? START_EVAL_DEFERRED : START_EVAL_DYNAMIC;
if (this.getToken().getSymbol() == start_eval) {
consumeToken();
AstNode node = expr(true);
try {
consumeToken(END_EVAL);
} catch (ParseException e) {
if (this.getToken().getSymbol() == FLOAT && node instanceof AstIdentifier) {
// Handle ${someMap.${someId}}
String mapKey = this.getToken().getImage().replace(".", "");
node = createAstDot(node, mapKey, true);
consumeToken();
consumeToken(END_EVAL);
} else {
throw e;
}
}
v = new AstEval(node, deferred);
} else if (required) {
fail(start_eval);
}
return v;
}
@Override
protected AstBracket createAstBracket(AstNode base, AstNode property, boolean lvalue, boolean strict) {
return new ExtendedAstBracket(base, property, lvalue, strict);
}
@Override
protected AstDot createAstDot(AstNode base, String property, boolean lvalue) {
return new ExtendedAstDot(base, property, lvalue);
}
}
/** Custom <code>Builder</code> class needed to implement a custom parser. */
@SuppressWarnings("serial")
protected static class ExtendedBuilder extends Builder {
@Override
public Tree build(String expression) throws ELException {
try {
return new ExtendedParser(this, expression).tree();
} catch (ScanException e) {
throw new ELException(LocalMessages.get("error.build", expression, e.getMessage()));
} catch (ParseException e) {
throw new ELException(LocalMessages.get("error.build", expression, e.getMessage()));
}
}
}
}