/*
 * 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 under the License.
 */
package org.apache.cocoon.forms.datatype.validationruleimpl;

import org.apache.cocoon.forms.datatype.ValidationRule;
import org.apache.cocoon.forms.util.DomHelper;
import org.w3c.dom.Element;
import org.outerj.expression.Expression;

/**
 * Builds {@link RangeValidationRule}s.
 * 
 * @version $Id$
 */
public class RangeValidationRuleBuilder extends AbstractValidationRuleBuilder {
    public ValidationRule build(Element validationRuleElement) throws Exception {
        RangeValidationRule rule = new RangeValidationRule();

        String minExprString = validationRuleElement.getAttribute("min");
        String maxExprString = validationRuleElement.getAttribute("max");

        if (minExprString.length() > 0 && maxExprString.length() > 0) {
            Expression expression = parseExpression(minExprString, validationRuleElement, "min");
            rule.setMinExpr(expression);
            expression = parseExpression(maxExprString, validationRuleElement, "max");
            rule.setMaxExpr(expression);
        } else if (minExprString.length() > 0) {
            Expression expression = parseExpression(minExprString, validationRuleElement, "min");
            rule.setMinExpr(expression);
        } else if (maxExprString.length() > 0) {
            Expression expression = parseExpression(maxExprString, validationRuleElement, "max");
            rule.setMaxExpr(expression);
        } else {
            throw new Exception("range validation rule requires a min and/or max attribute at " + DomHelper.getLocation(validationRuleElement));
        }

        buildFailMessage(validationRuleElement, rule);

        return rule;
    }
}