/*
* Copyright 2004-2005 the original author or authors.
*
* 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.springmodules.validation.util.fel.parser;
import org.springmodules.validation.util.fel.FelEvaluationException;
import org.springmodules.validation.util.fel.FelParseException;
import org.springmodules.validation.util.fel.Function;
import org.springmodules.validation.util.fel.FunctionExpressionParser;
import org.springmodules.validation.valang.functions.TargetBeanFunction;
import org.springmodules.validation.valang.parser.ParseException;
import org.springmodules.validation.valang.parser.SimpleValangBased;
import org.springmodules.validation.valang.parser.ValangParser;
/**
* A {@link FunctionExpressionParser} implementation that knows how to parse valang function expressions.
*
* @author Uri Boness
*/
public class ValangFunctionExpressionParser extends SimpleValangBased implements FunctionExpressionParser {
public Function parse(String expression) {
return new ValangFunction(expression);
}
/**
* A function that is associated with a valang function expression. This function evaluates the function on
* the given object and returns the result.
*/
protected class ValangFunction implements Function {
private String valangExpression;
private org.springmodules.validation.valang.functions.Function valangFunction;
public ValangFunction(String valangExpression) {
this.valangExpression = valangExpression;
ValangParser parser = createValangParser(valangExpression);
try {
this.valangFunction = parser.function(new TargetBeanFunction());
} catch (ParseException pe) {
throw new FelParseException("Could not parse valang function expression '" +
valangExpression + "'", pe);
}
}
public Object evaluate(Object argument) {
try {
return valangFunction.getResult(argument);
} catch (Throwable t) {
throw new FelEvaluationException("Could not evaluate valang expression '" +
valangExpression + "' on bean '" + String.valueOf(argument) + "'", t);
}
}
}
}