/*
 * 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.
 *
 * $Header:$
 */
package org.apache.beehive.netui.tags.html;

import javax.servlet.jsp.JspException;

/**
 * Abstract base class extending the <code>HtmlDataSourceTag</code> and adding support
 * for the <code>defaultValue</code> attribute.
 */
abstract public class HtmlDefaultableDataSourceTag
        extends HtmlDataSourceTag
{
    protected Object _defaultValue;           // A String that contains or references the data to render for the default value of this tag.

    /**
     * Sets the default value (can be an expression).
     * @param defaultValue the default value
     * @jsptagref.attributedescription <p><b>Use in &lt;netui:checkBoxGroup>, &lt;netui:checkBox>,
     * &lt;netui:radioButtonGroup>, and &lt;netui:select> tags</b></p>
     * <p>Sets the preselected value or values.
     * <p>The <code>defaultValue</code> attribute takes either a String literal or
     * a data binding expression.
     * <p>If the <code>defaultValue</code> attribute has a String value (or if
     * the data binding expression points to a String), then a single value
     * will be preselected.
     * <p>If the <code>defaultValue</code> attribute points to a String[] object
     * (or any object which can be iterated over), then
     * multiple values will be preselected.
     *
     *
     * <p><b>Use in &lt;netui:textArea> and &lt;netui:textBox> tags</b></p>
     * <p>Sets the initial display text.</p>
     * <p>The <code>defaultValue</code> attribute takes either a String literal or
     * a data binding expression that points to a String.
     * @jsptagref.databindable Read / Write
     * @jsptagref.attributesyntaxvalue <i>string_or_expression_default</i>
     * @netui:attribute required="false" rtexprvalue="true"  type="java.lang.Object"
     * description="Sets the default value of the control which is used if the object bound to is null."
     */
    public void setDefaultValue(Object defaultValue)
            throws JspException
    {
        _defaultValue = defaultValue;
    }

    /**
     * Release any acquired resources.
     */
    protected void localRelease()
    {
        super.localRelease();
        _defaultValue = null;
    }
}
