/*

 * Copyright (c) 2008, 2013, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package com.sun.beans.decoder;

/**

 * This class is intended to handle <string> element.

 * This element specifies {@link String} values.

 * The result value is created from text of the body of this element.

 * For example:<pre>

 * &lt;string&gt;description&lt;/string&gt;</pre>

 * is equivalent to {@code "description"} in Java code.

 * The value of inner element is calculated

 * before adding to the string using {@link String#valueOf(Object)}.

 * Note that all characters are used including whitespaces (' ', '\t', '\n', '\r').

 * So the value of the element<pre>

 * &lt;string&gt&lt;true&gt&lt;/string&gt;</pre>

 * is not equal to the value of the element<pre>

 * <string>

 *     <true>

 * &lt;/string&gt;</pre>

 * <p>The following attribute is supported:

 * <dl>

 * <dt>id

 * <dd>the identifier of the variable that is intended to store the result

 * </dl>

 *

 * @since 1.7

 *

 * @author Sergey A. Malenkov

 */

public class StringElementHandler extends ElementHandler {

    private StringBuilder sb = new StringBuilder();

    private ValueObject value = ValueObjectImpl.NULL;

    /**

     * Adds the character that contained in this element.

     *

     * @param ch  the character

     */

    @Override

    public final void addCharacter(char ch) {

        if (this.sb == null) {

            throw new IllegalStateException("Could not add chararcter to evaluated string element");

        }

        this.sb.append(ch);

    }

    /**

     * Adds the string value of the argument to the string value of this element.

     *

     * @param argument  the value of the element that contained in this one

     */

    @Override

    protected final void addArgument(Object argument) {

        if (this.sb == null) {

            throw new IllegalStateException("Could not add argument to evaluated string element");

        }

        this.sb.append(argument);

    }

    /**

     * Returns the value of this element.

     *

     * @return the value of this element

     */

    @Override

    protected final ValueObject getValueObject() {

        if (this.sb != null) {

            try {

                this.value = ValueObjectImpl.create(getValue(this.sb.toString()));

            }

            catch (RuntimeException exception) {

                getOwner().handleException(exception);

            }

            finally {

                this.sb = null;

            }

        }

        return this.value;

    }

    /**

     * Returns the text of the body of this element.

     * This method evaluates value from text of the body,

     * and should be overridden in those handlers

     * that extend behavior of this element.

     *

     * @param argument  the text of the body

     * @return evaluated value

     */

    protected Object getValue(String argument) {

        return argument;

    }

}