/*
 * 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.taglibs.standard.tag.common.sql;

import javax.servlet.jsp.JspException;
import javax.servlet.jsp.JspTagException;
import javax.servlet.jsp.jstl.sql.SQLExecutionTag;
import javax.servlet.jsp.tagext.BodyTagSupport;

import org.apache.taglibs.standard.resources.Resources;


/**
 * <p>Tag handler for &lt;Param&gt; in JSTL, used to set
 * parameter values for a SQL statement.</p>
 *
 * @author Hans Bergsten
 */

public abstract class ParamTagSupport extends BodyTagSupport {
    protected Object value;

    //*********************************************************************
    // Tag logic

    @Override
    public int doEndTag() throws JspException {
        SQLExecutionTag parent = (SQLExecutionTag)
                findAncestorWithClass(this, SQLExecutionTag.class);
        if (parent == null) {
            throw new JspTagException(
                    Resources.getMessage("SQL_PARAM_OUTSIDE_PARENT"));
        }

        Object paramValue = null;
        if (value != null) {
            paramValue = value;
        } else if (bodyContent != null) {
            paramValue = bodyContent.getString().trim();
            if (((String) paramValue).trim().length() == 0) {
                paramValue = null;
            }
        }

        parent.addSQLParameter(paramValue);
        return EVAL_PAGE;
    }
}
