/*
* 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.
*/
package org.apache.cocoon.components.modules.output;
import java.util.Iterator;
import java.util.Map;
import org.apache.avalon.framework.configuration.Configuration;
import org.apache.avalon.framework.logger.Logger;
import org.apache.cocoon.environment.ObjectModelHelper;
import org.apache.cocoon.environment.Session;
/**
* Abstraction layer to encapsulate different output
* destinations. Configuration option <key-prefix> defaults to
* "org.apache.cocoon.components.modules.output.OutputModule"+":"
*
* Can be used with different isolation-level: default is "0" being
* no isolation at all, values are immediately visible but are removed
* on a rollback; "1" keeps the values at a save place until either
* rollback or commit is called. Then values are either discarded or
* copied to the final destination.
*
* @author <a href="mailto:haul@apache.org">Christian Haul</a>
* @version CVS $Id: SessionAttributeOutputModule.java,v 1.3 2004/03/05 13:02:49 bdelacretaz Exp $
*/
public class SessionAttributeOutputModule extends AbstractOutputModule implements OutputModule {
public final String PREFIX = "org.apache.cocoon.components.modules.output.OutputModule";
public final String TRANS_PREFIX = "org.apache.cocoon.components.modules.output.OutputModule.SessionAttributeOutputModule.transient";
public final String ROLLBACK_LIST = "org.apache.cocoon.components.modules.output.OutputModule.SessionAttributeOutputModule.rollback";
/**
* communicate an attribute value to further processing logic.
* @param modeConf column's mode configuration from resource
* description. This argument is optional.
* @param objectModel The objectModel
* @param name The attribute's label, consisting of "table.column"
* or "table.column[index]" in case of multiple attributes of the
* same spec.
* @param value The attriute's value.
* */
public void setAttribute( Configuration modeConf, Map objectModel, String name, Object value ) {
if (this.settings.get("isolation-level","0").equals("1")) {
if (getLogger().isDebugEnabled())
getLogger().debug("setting transient ['"+name+"'] to ['"+value+"']");
this.transientSetAttribute(objectModel, TRANS_PREFIX, name, value);
} else {
// use read uncommitted isolation level
Session session = ObjectModelHelper.getRequest(objectModel).getSession();
name = getName(name);
if (!this.attributeExists(objectModel, ROLLBACK_LIST, name)) {
Object tmp = session.getAttribute(name);
this.transientSetAttribute(objectModel, ROLLBACK_LIST, name, tmp);
}
if (getLogger().isDebugEnabled())
getLogger().debug("setting ['"+name+"'] to ['"+value+"']");
session.setAttribute(name, value);
}
}
/**
* If a database transaction needs to rollback, this is called to
* inform the further processing logic about this fact. All
* already set attribute values are invalidated. <em>This is difficult
* because only the request object can be used to synchronize this
* and build some kind of transaction object. Beaware that sending
* your data straight to some beans or other entities could result
* in data corruption!</em>
* */
public void rollback( Configuration modeConf, Map objectModel, Exception e ) {
if (this.settings.get("isolation-level","0").equals("1")) {
if (getLogger().isDebugEnabled())
getLogger().debug("rolling back");
this.rollback(objectModel, TRANS_PREFIX);
} else {
if (getLogger().isDebugEnabled())
getLogger().debug("start rolling back");
Session session = ObjectModelHelper.getRequest(objectModel).getSession();
Object tmp = this.prepareCommit(objectModel,ROLLBACK_LIST);
if (tmp != null) {
Map rollbackList = (Map) tmp;
Iterator iter = rollbackList.keySet().iterator();
while(iter.hasNext()) {
String key = (String) iter.next();
Object val = rollbackList.get(key);
if (val != null) {
if (getLogger().isDebugEnabled())
getLogger().debug("rolling back ['"+key+"'] to ['"+val+"']");
session.setAttribute(key, val);
} else {
if (getLogger().isDebugEnabled())
getLogger().debug("rolling back ['"+key+"']");
session.removeAttribute(key);
}
}
}
}
if (getLogger().isDebugEnabled())
getLogger().debug("done rolling back");
String prefix = (String) this.settings.get("key-prefix", PREFIX );
if (prefix!="") {
ObjectModelHelper.getRequest(objectModel).getSession().setAttribute(prefix+":",e.getMessage());
} else {
ObjectModelHelper.getRequest(objectModel).getSession().setAttribute("errorMessage",e.getMessage());
}
}
/**
* Signal that the database transaction completed
* successfully. See notes on @link{rollback}.
* */
public void commit( Configuration modeConf, Map objectModel ) {
if (this.settings.get("isolation-level","0").equals("1")) {
Logger logger = getLogger();
if (logger.isDebugEnabled())
logger.debug("prepare commit");
Map aMap = this.prepareCommit(objectModel, TRANS_PREFIX);
if (aMap == null) {
return;
}
Iterator iter = aMap.keySet().iterator();
if (!iter.hasNext()){
return;
}
String prefix = (String) this.settings.get("key-prefix", PREFIX );
if (prefix != "") {
prefix = prefix+":";
} else {
prefix = null;
}
Session session = ObjectModelHelper.getRequest(objectModel).getSession();
while (iter.hasNext()) {
String key = (String) iter.next();
Object value = aMap.get(key);
if (prefix != null) { key = prefix + key; }
if (logger.isDebugEnabled())
logger.debug("committing ['"+key+"'] to ['"+value+"']");
session.setAttribute(key, value);
}
if (logger.isDebugEnabled())
logger.debug("done commit");
} else {
if (getLogger().isDebugEnabled())
getLogger().debug("commit");
this.prepareCommit(objectModel, ROLLBACK_LIST);
}
}
protected String getName( String name ) {
String prefix = (String) this.settings.get("key-prefix", PREFIX );
return (prefix == "" ? name : prefix+":"+name);
}
}