Christoph, thanks for the explanation(s) and the links. I'll definitely read up on some of these things. Just a few comments inline, though.
On Wed, 10 Sep 2003 12:28:42 +0200, Christoph Gaffga wrote: >> can you briefly explain the differences between the two transformers. >> Whilst I am very familiar with the CastorTransformer (and Castor XML/JDO), >> I'd appreciate a quick overview of the functionality of the >> BetwixtTransformer, and what advantages it would offer to using the >> CastorTransformer. > >I just compared some XML-Binding frameworks like JAXB, Castor, XMLBeans, >JiBX etc. >The one I most liked was Betwixt. It is very easy to use, produces SAX >events, it works with EJBs RemoteInterface, easy to use mapping files, clean >XML, supports Maps and Collection in a way I like it. And it is more >Beans-centric, good if you want to use your existing beans (Castor is more >Schema-centric, I think). Castor can work in both modes. Iow, use existing beans/Java classes by supplying a binding file, or start with a XML Schema and have FieldHandlers generated for you that assist you in un-/marshalling to/from XML. >Some links: >How does Betwixt compare to technologies like JAXB and Castor? >http://jakarta.apache.org/commons/betwixt/faq.html#comparison > >Writing Entity Beans >http://jakarta.apache.org/commons/betwixt/guide/writing.html#EJB > >And the javadoc for BetwixtTransformer: > >Betwixt transformer marshals a object from the Sitemap, Session, Request >or the Conext into a series of SAX events. >Configuation: The betwixt transformer can be configured to not output > element reference ids. The default setting is to output > reference IDs. ><map:transformer > name="betwixt" > src="org.apache.cocoon.transformation.BetwixtTransformer"> > <ref-ids>true</ref-ids> ></map:transformer> > >Sample: ><root xmlns:betwixt="http://apache.org/cocoon/betwixt-transfomer";> > <betwixt:include name="invoice"/> > <betwixt:include name="product" scope="sitemap"/> > <betwixt:include name="product2" element="other-product"/> ></root> Very similar, indeed .. ;-). >The BetwixtTransfomer support only one Element "betwixt:include". >This element is replaced with the marshalled object. The Object given >through the attribute "name" will be searched in the request, session, >context and at least in sitemap. >If the scope is explicitly given, the object will ge located only there. >The attribute "element" can be given to specify an alternativ >root element for the object. Collections are marshalled by marshalling >each object it contains. >@see Betwixt Projekt Homepage (http://jakarta.apache.org/commons/betwixt/) >@author Christoph Gaffga ([EMAIL PROTECTED]) > > >So, you see, it's very similar to the CastorTransformer usage. >If you test it, let me here, what you think about. > >regards >Christoph > > >----- Original Message ----- >From: "Werner Guttmann" <[EMAIL PROTECTED]> >To: "Christoph Gaffga" <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]> >Cc: <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]> >Sent: Wednesday, September 10, 2003 10:04 AM >Subject: Re: EJB + Cocoon, "Best Practices" / Betwixt > > >> Christoph, >> >> can you briefly explain the differences between the two transformers. >Whilst I am very familiar with the >> CastorTransformer (and Castor XML/JDO), I'd appreciate a quick overview of >the functionality of the >> BetwixtTransformer, and what advantages it would offer to using the >CastorTransformer. >> >> >> that invokes the EJB and returns the DTO. It then passes the DTO to >> >Betwixt >> >> which converts it to SAX events. I posted the BeanGenerator on the >list a >> > >> >Perheaps you are also interested in a BetwixtTransformer, analoge to >> >CastorTransformer? >> >I post it here, perheaps anyone can put it in the scratchpad? >> > >> >regards >> >Christoph >> > >> > >> >org.apache.cocoon.tranformation.BetwixtTransformer: >> >--------------------------------------------------- >> > >> >/* >> > >> >>=========================================================================== >= >> > The Apache Software License, Version 1.1 >> > >> >>=========================================================================== >= >> > Copyright (C) 1999-2003 The Apache Software Foundation. All rights >> >reserved. >> > Redistribution and use in source and binary forms, with or without >> >modifica- >> > tion, 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 the Apache Software Foundation >> >(http://www.apache.org/)." >> > Alternately, this acknowledgment may appear in the software itself, >> >if >> > and wherever such third-party acknowledgments normally appear. >> > 4. The names "Apache Cocoon" and "Apache Software Foundation" must not >> >be >> > used to endorse or promote products derived from this software >> >without >> > prior written permission. For written permission, please contact >> > [EMAIL PROTECTED] >> > 5. Products derived from this software may not be called "Apache", nor >> >may >> > "Apache" appear in their name, without prior written permission of >> >the >> > Apache Software Foundation. >> > 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 >> >THE >> > APACHE SOFTWARE FOUNDATION OR ITS CONTRIBUTORS BE LIABLE FOR ANY >> >DIRECT, >> > INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES >> >(INCLU- >> > DING, 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. >> > This software consists of voluntary contributions made by many >> >individuals >> > on behalf of the Apache Software Foundation and was originally >created >> >by >> > Stefano Mazzocchi <[EMAIL PROTECTED]>. For more information on the >> >Apache >> > Software Foundation, please see <http://www.apache.org/>. >> > */ >> > >> >package org.apache.cocoon.transformation; >> > >> >import java.lang.reflect.Proxy; >> >import java.util.Collection; >> >import java.util.Iterator; >> >import java.util.Map; >> > >> >import org.apache.avalon.framework.configuration.Configurable; >> >import org.apache.avalon.framework.configuration.Configuration; >> >import org.apache.avalon.framework.configuration.ConfigurationException; >> >import org.apache.avalon.framework.parameters.Parameters; >> >import org.apache.cocoon.environment.Context; >> >import org.apache.cocoon.environment.ObjectModelHelper; >> >import org.apache.cocoon.environment.Request; >> >import org.apache.cocoon.environment.Session; >> >import org.apache.cocoon.environment.SourceResolver; >> >import org.apache.commons.betwixt.XMLIntrospector; >> >import org.apache.commons.betwixt.io.SAXBeanWriter; >> >import org.apache.commons.betwixt.strategy.ClassNormalizer; >> >import org.apache.commons.logging.impl.LogKitLogger; >> >import org.xml.sax.Attributes; >> >import org.xml.sax.SAXException; >> > >> >/** >> > * Betwixt transformer marshals a object from the Sitemap, Session, >Request >> >or >> > * the Conext into a series of SAX events. >> > * >> > * Configuation: The betwixt transformer can be configured to not output >> >element >> > * reference ids. The default setting is to output reference IDs. >> > * <pre> >> > * <map:transformer name="betwixt" >> >src="org.apache.cocoon.transformation.BetwixtTransformer" >> > * <ref-ids>true</ref-ids> >> > * </map:transformer> >> > * </pre> >> > * >> > * A sample for the use: >> > * <pre> >> > * <root >> >xmlns:betwixt="http://apache.org/cocoon/betwixt-transfomer"> >> > * <betwixt:include name="invoice" /> >> > * <betwixt:include name="product" scope="sitemap" /> >> > * <betwixt:include name="product2" element="other-product" /> >> > * </root> >> > * </pre> >> > * The <code>BetwixtTransfomer</code> support only one Element >> ><code>betwixt:include</code>. >> > * This element is replaced with the marshalled object. The Object given >> >through the >> > * attribute <code>name</code> will be searched in the ><code>request</code>, >> ><code>session</code>, >> > * <code>context</code> and at least in <code>sitemap</code>. >> > * If the scope is explicitly given, the object will ge located only >there. >> > * The attribute <code>element</code> can be given to specify an >alternativ >> > * root element for the object. Collections are marshalled by marshalling >> > * each object it contains. >> > * >> > * @see <a href="http://jakarta.apache.org/commons/betwixt/";>Betwixt >Projekt >> >Homepage</a> >> > * @author <a href="mailto:[EMAIL PROTECTED]">Christoph Gaffga</a> >> > */ >> >public class BetwixtTransformer extends AbstractTransformer implements >> >Configurable { >> > private static final String BETWIXT_NSURI = >> >"http://apache.org/cocoon/betwixt-transfomer";; >> > >> > private final static String CMD_INCLUDE = "include"; >> > private final static String ATTR_NAME = "name"; >> > private final static String ATTR_SCOPE = "scope"; >> > private final static String SCOPE_SITEMAP = "sitemap"; >> > private final static String SCOPE_SESSION = "session"; >> > private final static String SCOPE_REQUEST = "request"; >> > private final static String SCOPE_CONTEXT = "context"; >> > private final static String ATTR_ELEMENT = "element"; >> > private final static String CONF_REFIDS = "ref-ids"; >> > >> > // Introspector to share XMLBeanInfo cache >> > private static XMLIntrospector introspector; >> > >> > private boolean refIds = true; >> > >> > private Map objectModel = null; >> > private boolean inBetwixtElement = false; >> > private SAXBeanWriter beanWriter = null; >> > >> > public void configure(Configuration conf) throws ConfigurationException >{ >> > final String refIds = conf.getChild(CONF_REFIDS).getValue("true"); >> > this.refIds = "false".equals(refIds) || "no".equals(refIds); >> > } >> > >> > public void setup(SourceResolver resolver, Map objectModel, String src, >> >Parameters par) { >> > this.objectModel = objectModel; >> > } >> > >> > public void recycle() { >> > this.objectModel = null; >> > this.inBetwixtElement = false; >> > } >> > >> > public void endElement(String uri, String name, String raw) throws >> >SAXException { >> > if (BETWIXT_NSURI.equals(uri)) { >> > this.inBetwixtElement = false; >> > } else { >> > super.endElement(uri, name, raw); >> > } >> > } >> > >> > public void startElement(String uri, String name, String raw, >Attributes >> >attr) throws >> > SAXException { >> > if (BETWIXT_NSURI.equals(uri)) { >> > this.inBetwixtElement = true; >> > process(name, attr); >> > } else { >> > super.startElement(uri, name, raw, attr); >> > } >> > } >> > >> > public void characters(char[] ch, int start, int len) throws >SAXException >> >{ >> > if (!this.inBetwixtElement) { >> > super.characters(ch, start, len); >> > } >> > } >> > >> > private void process(String command, Attributes attr) throws >SAXException >> >{ >> > if (CMD_INCLUDE.equals(command)) { >> > final String scope = attr.getValue(ATTR_SCOPE); >> > final String name = attr.getValue(ATTR_NAME); >> > if (name == null) { >> > throw new SAXException("Required attribute name is missing on >> >element " + CMD_INCLUDE); >> > } >> > >> > final String element = attr.getValue(ATTR_ELEMENT); >> > if (element == null) { >> > throw new SAXException("Attribute " + ATTR_ELEMENT + " can not be >> >empty"); >> > } >> > >> > Object bean = null; >> > if (scope == null || SCOPE_REQUEST.equals(scope)) { >> > final Request request = >ObjectModelHelper.getRequest(objectModel); >> > bean = request.getAttribute(name); >> > } >> > if ( (scope == null && bean == null) || >SCOPE_SESSION.equals(scope)) { >> > final Session session = >> >ObjectModelHelper.getRequest(objectModel).getSession(false); >> > if (session != null) { >> > bean = session.getAttribute(name); >> > } >> > } >> > if ( (scope == null && bean == null) || >SCOPE_CONTEXT.equals(scope)) { >> > final Context context = >ObjectModelHelper.getContext(objectModel); >> > if (context != null) { >> > bean = context.getAttribute(name); >> > } >> > } >> > if ( (scope == null && bean == null) || >SCOPE_SITEMAP.equals(scope)) { >> > bean = objectModel.get(name); >> > } >> > >> > if (bean != null) { >> > includeBean(name, bean, element); >> > } else { >> > getLogger().warn("Bean " + name + " could not be found"); >> > } >> > } else { >> > throw new SAXException("Unknown command: " + command); >> > } >> > } >> > >> > private void includeBean(String name, Object bean, String element) { >> > try { >> > if (this.beanWriter == null) { >> > this.beanWriter = new SAXBeanWriter(this.contentHandler); >> > synchronized (this.introspector) { >> > if (this.introspector == null) { >> > this.introspector = this.beanWriter.getXMLIntrospector(); >> > this.introspector.setLog(new LogKitLogger("betwixt")); >> > /* The following is needed for EJB */ >> > this.introspector.setClassNormalizer(new ClassNormalizer() { >> > public Class normalize(Class clazz) { >> > if (Proxy.isProxyClass(clazz) && >> >clazz.getInterfaces().length > 0) { >> > return clazz.getInterfaces()[0]; >> > } >> > return super.normalize(clazz); >> > } >> > }); >> > >> > } else { >> > this.beanWriter.setXMLIntrospector(this.introspector); >> > } >> > } >> > beanWriter.getBindingConfiguration().setMapIDs(this.refIds); >> > } >> > >> > if (bean instanceof Collection) { >> > Iterator i = ( (Collection) bean).iterator(); >> > while (i.hasNext()) { >> > if (element == null) { >> > beanWriter.write(bean); >> > } else { >> > beanWriter.write(element, bean); >> > } >> > } >> > } else { >> > if (element == null) { >> > beanWriter.write(bean); >> > } else { >> > beanWriter.write(element, bean); >> > } >> > } >> > } catch (Exception e) { >> > getLogger().warn("Failed to marshal bean " + name, e); >> > } >> > } >> > >> >} >> > >> > >> > >> >--------------------------------------------------------------------- >> >To unsubscribe, e-mail: [EMAIL PROTECTED] >> >For additional commands, e-mail: [EMAIL PROTECTED] >> > >> >> >> > --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
