/*
* Copyright (c) 2001-2007 Sun Microsystems, Inc. All rights reserved.
*
* The Sun Project JXTA(TM) Software License
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* 3. The end-user documentation included with the redistribution, if any, must
* include the following acknowledgment: "This product includes software
* developed by Sun Microsystems, Inc. for JXTA(TM) technology."
* Alternately, this acknowledgment may appear in the software itself, if
* and wherever such third-party acknowledgments normally appear.
*
* 4. The names "Sun", "Sun Microsystems, Inc.", "JXTA" and "Project JXTA" must
* not be used to endorse or promote products derived from this software
* without prior written permission. For written permission, please contact
* Project JXTA at http://www.jxta.org.
*
* 5. Products derived from this software may not be called "JXTA", nor may
* "JXTA" appear in their name, without prior written permission of Sun.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL SUN
* MICROSYSTEMS OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
* OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* JXTA is a registered trademark of Sun Microsystems, Inc. in the United
* States and other countries.
*
* Please see the license information page at :
* <http://www.jxta.org/project/www/license.html> for instructions on use of
* the license in source files.
*
* ====================================================================
*
* This software consists of voluntary contributions made by many individuals
* on behalf of Project JXTA. For more information on Project JXTA, please see
* http://www.jxta.org.
*
* This license is based on the BSD license adopted by the Apache Foundation.
*/
package net.jxta.document;
/**
* Extendable advertisements provide features for allowing inheritance of
* advertisement types. The core and standard JXTA advertisements all allow
* extension by extending this class.
*
* @see net.jxta.document.Advertisement
* @see net.jxta.document.AdvertisementFactory
* @see net.jxta.document.Document
* @see net.jxta.document.MimeMediaType
*/
public abstract class ExtendableAdvertisement extends Advertisement {
/**
* If {@code true} then the advertisement will be pretty print formatted
* when it is output as XML. Currently this must be specified at
* construction time as it is normally a preference per advertisement type.
*/
private transient boolean formatted;
/**
* Default constructor. The advertisement will *not* be pretty-printed when
* it is output as XML.
*/
protected ExtendableAdvertisement() {
this(false);
}
/**
* @param formatted If {@code true} then the advertisement will be pretty
* print formatted when it is output as XML.
*/
protected ExtendableAdvertisement(boolean formatted) {
this.formatted = formatted;
}
/**
* Returns the base type of this advertisement hierarchy. Typically, only
* the most basic advertisement of a type will implement this method and
* declare it as <code>final</code>.
*
* @return String the base type of advertisements in this hierarchy.
*/
public abstract String getBaseAdvType();
/**
* Process an individual element from the document during parse. Normally,
* implementations will allow the base advertisements a chance to handle
* the element before attempting to handle the element themselves. ie.
* <p/>
* <pre><code>
* protected boolean handleElement(Element elem) {
*
* if (super.handleElement()) {
* // it's been handled.
* return true;
* }
* <i>... handle elements here ...</i>
*
* // we don't know how to handle the element
* return false;
* }
* </code></pre>
*
* @param elem The element to be processed.
* @return {@code true} if the element was recognized, otherwise false.
*/
protected boolean handleElement(Element elem) {
// we don't handle any elements.
return false;
}
/**
* Process an individual attribute from the document root node. Normally,
* implementations will allow the base advertisements a chance to handle
* the attribute before attempting to handle the element themselves. ie.
* <p/>
* <p/><pre><code>
* protected boolean handleAttribute( Attribute elem ) {
* <p/>
* if (super.handleAttribute()) {
* // it's been handled.
* return true;
* }
*
* <i>... handle attributes here ...</i>
*
* // we don't know how to handle the attribute
* return false;
* }
* </code></pre>
*
* @param attrib The attribute to be processed.
* @return {@code true} if the attribute was recognized, otherwise false.
*/
protected boolean handleAttribute(Attribute attrib) {
// "handle" the attributes that we choose to ignore.
if ("xmlns:jxta".equals(attrib.getName())) {
return true;
} else if ("xml:space".equals(attrib.getName())) {
return true;
} else if ("type".equals(attrib.getName())) {
return true;
}
return false;
}
/**
* {@inheritDoc}
* <p/>
* We don't have any content to add, just build the document instance and
* return it to implementations that actually do something with it.
*/
@Override
public Document getDocument(MimeMediaType encodeAs) {
Document adv = StructuredDocumentFactory.newStructuredDocument(encodeAs, getBaseAdvType());
if (!(adv instanceof Attributable)) {
throw new IllegalArgumentException("Advertisements require document type with attribute support.");
}
if (adv instanceof XMLDocument) {
XMLDocument xmlAdv = (XMLDocument) adv;
xmlAdv.addAttribute("xmlns:jxta", "http://jxta.org");
if (!formatted) {
xmlAdv.addAttribute("xml:space", "preserve");
}
}
if (!getBaseAdvType().equals(getAdvType())) {
((Attributable) adv).addAttribute("type", getAdvType());
}
return adv;
}
}