/*

 * reserved comment block

 * DO NOT REMOVE OR ALTER!

 */

/*

 * Copyright 1999-2004 The Apache Software Foundation.

 *

 * 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.

 */

/*

 * $Id: Serializer.java,v 1.2.4.1 2005/09/15 08:15:22 suresh_emailid Exp $

 */

package com.sun.org.apache.xml.internal.serializer;

import java.io.IOException;

import java.io.OutputStream;

import java.io.Writer;

import java.util.Properties;

import org.xml.sax.ContentHandler;

/**

 * The Serializer interface is implemented by a serializer to enable users to:

 * <ul>

 * <li>get and set streams or writers

 * <li>configure the serializer with key/value properties

 * <li>get an org.xml.sax.ContentHandler or a DOMSerializer to provide input to

 * </ul>

 *

 * <p>

 * Here is an example using the asContentHandler() method:

 * <pre>

 * java.util.Properties props =

 *   OutputPropertiesFactory.getDefaultMethodProperties(Method.TEXT);

 * Serializer ser = SerializerFactory.getSerializer(props);

 * java.io.PrintStream ostream = System.out;

 * ser.setOutputStream(ostream);

 *

 * // Provide the SAX input events

 * ContentHandler handler = ser.asContentHandler();

 * handler.startDocument();

 * char[] chars = { 'a', 'b', 'c' };

 * handler.characters(chars, 0, chars.length);

 * handler.endDocument();

 *

 * ser.reset(); // get ready to use the serializer for another document

 *              // of the same output method (TEXT).

 * </pre>

 *

 * <p>

 * As an alternate to supplying a series of SAX events as input through the

 * ContentHandler interface, the input to serialize may be given as a DOM.

 * <p>

 * For example:

 * <pre>

 * org.w3c.dom.Document     inputDoc;

 * com.sun.org.apache.xml.internal.serializer.Serializer   ser;

 * java.io.Writer owriter;

 *

 * java.util.Properties props =

 *   OutputPropertiesFactory.getDefaultMethodProperties(Method.XML);

 * Serializer ser = SerializerFactory.getSerializer(props);

 * owriter = ...;  // create a writer to serialize the document to

 * ser.setWriter( owriter );

 *

 * inputDoc = ...; // create the DOM document to be serialized

 * DOMSerializer dser = ser.asDOMSerializer(); // a DOM will be serialized

 * dser.serialize(inputDoc); // serialize the DOM, sending output to owriter

 *

 * ser.reset(); // get ready to use the serializer for another document

 *              // of the same output method.

 * </pre>

 *

 * This interface is a public API.

 *

 * @see Method

 * @see OutputPropertiesFactory

 * @see SerializerFactory

 * @see DOMSerializer

 * @see ContentHandler

 *

 * @xsl.usage general

 */

public interface Serializer {

    /**

     * Specifies an output stream to which the document should be

     * serialized. This method should not be called while the

     * serializer is in the process of serializing a document.

     * <p>

     * The encoding specified in the output {@link Properties} is used, or

     * if no encoding was specified, the default for the selected

     * output method.

     * <p>

     * Only one of setWriter() or setOutputStream() should be called.

     *

     * @param output The output stream

     */

    public void setOutputStream(OutputStream output);

    /**

     * Get the output stream where the events will be serialized to.

     *

     * @return reference to the result stream, or null if only a writer was

     * set.

     */

    public OutputStream getOutputStream();

    /**

     * Specifies a writer to which the document should be serialized.

     * This method should not be called while the serializer is in

     * the process of serializing a document.

     * <p>

     * The encoding specified for the output {@link Properties} must be

     * identical to the output format used with the writer.

     *

     * <p>

     * Only one of setWriter() or setOutputStream() should be called.

     *

     * @param writer The output writer stream

     */

    public void setWriter(Writer writer);

    /**

     * Get the character stream where the events will be serialized to.

     *

     * @return Reference to the result Writer, or null.

     */

    public Writer getWriter();

    /**

     * Specifies an output format for this serializer. It the

     * serializer has already been associated with an output format,

     * it will switch to the new format. This method should not be

     * called while the serializer is in the process of serializing

     * a document.

     * <p>

     * The standard property keys supported are: "method", "version", "encoding",

     * "omit-xml-declaration", "standalone", doctype-public",

     * "doctype-system", "cdata-section-elements", "indent", "media-type".

     * These property keys and their values are described in the XSLT recommendation,

     * see {@link <a href="http://www.w3.org/TR/1999/REC-xslt-19991116"> XSLT 1.0 recommendation</a>}

     * <p>

     * The non-standard property keys supported are defined in {@link OutputPropertiesFactory}.

     *

     * <p>

     * This method can be called multiple times before a document is serialized. Each

     * time it is called more, or over-riding property values, can be specified. One

     * property value that can not be changed is that of the "method" property key.

     * <p>

     * The value of the "cdata-section-elements" property key is a whitespace

     * separated list of elements. If the element is in a namespace then

     * value is passed in this format: {uri}localName

     * <p>

     * If the "cdata-section-elements" key is specified on multiple calls

     * to this method the set of elements specified in the value

     * is not replaced from one call to the

     * next, but it is cumulative across the calls.

     *

     * @param format The output format to use, as a set of key/value pairs.

     */

    public void setOutputFormat(Properties format);

    /**

     * Returns the output format properties for this serializer.

     *

     * @return The output format key/value pairs in use.

     */

    public Properties getOutputFormat();

    /**

     * Return a {@link ContentHandler} interface to provide SAX input to.

     * Through the returned object the document to be serailized,

     * as a series of SAX events, can be provided to the serialzier.

     * If the serializer does not support the {@link ContentHandler}

     * interface, it will return null.

     * <p>

     * In principle only one of asDOMSerializer() or asContentHander()

     * should be called.

     *

     * @return A {@link ContentHandler} interface into this serializer,

     *  or null if the serializer is not SAX 2 capable

     * @throws IOException An I/O exception occured

     */

    public ContentHandler asContentHandler() throws IOException;

    /**

     * Return a {@link DOMSerializer} interface into this serializer.

     * Through the returned object the document to be serialized,

     * a DOM, can be provided to the serializer.

     * If the serializer does not support the {@link DOMSerializer}

     * interface, it should return null.

     * <p>

     * In principle only one of asDOMSerializer() or asContentHander()

     * should be called.

     *

     * @return A {@link DOMSerializer} interface into this serializer,

     *  or null if the serializer is not DOM capable

     * @throws IOException An I/O exception occured

     */

    public DOMSerializer asDOMSerializer() throws IOException;

    /**

     * This method resets the serializer.

     * If this method returns true, the

     * serializer may be used for subsequent serialization of new

     * documents. It is possible to change the output format and

     * output stream prior to serializing, or to reuse the existing

     * output format and output stream or writer.

     *

     * @return True if serializer has been reset and can be reused

     */

    public boolean reset();

}