/*==========================================================================*\
| $Id: ReadOnlyEditingContext.java,v 1.1 2011/12/25 02:24:54 stedwar2 Exp $
|*-------------------------------------------------------------------------*|
| Copyright (C) 2006-2011 Virginia Tech
|
| This file is part of Web-CAT.
|
| Web-CAT is free software; you can redistribute it and/or modify
| it under the terms of the GNU Affero General Public License as published
| by the Free Software Foundation; either version 3 of the License, or
| (at your option) any later version.
|
| Web-CAT 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 for more details.
|
| You should have received a copy of the GNU Affero General Public License
| along with Web-CAT; if not, see <http://www.gnu.org/licenses/>.
\*==========================================================================*/
package org.webcat.woextensions;
import org.webcat.core.Application;
import org.webcat.core.QualifierAugmenter;
import org.webcat.woextensions.ReadOnlyEditingContext;
import org.apache.log4j.Logger;
import com.webobjects.eocontrol.EOEditingContext;
import com.webobjects.eocontrol.EOEnterpriseObject;
import com.webobjects.eocontrol.EOFetchSpecification;
import com.webobjects.eocontrol.EOGlobalID;
import com.webobjects.eocontrol.EOObjectStore;
import com.webobjects.eocontrol.EOQualifier;
import com.webobjects.foundation.NSArray;
//-------------------------------------------------------------------------
/**
* An editing context that has its {@link #saveChanges()} method overridden to
* throw out the changes, effectively making it read-only. Calls to methods
* that would otherwise have altered the object store are logged as well as
* errors, along with a stack trace showing where the modification was
* attempted.
* </p><p>
* Use the {@link Application#newReadOnlyEditingContext()} and
* {@link Application#releaseReadOnlyEditingContext()} methods to manage the
* lifetimes of these objects.
* </p>
*
* @author Tony Allevato
* @author Last changed by $Author: stedwar2 $
* @version $Revision: 1.1 $, $Date: 2011/12/25 02:24:54 $
*/
public class ReadOnlyEditingContext
extends WCEC
{
//~ Constructor ...........................................................
// ----------------------------------------------------------
/**
* Creates a new object.
* @param os the parent object store
*/
public ReadOnlyEditingContext(EOObjectStore os)
{
super(os);
}
// ----------------------------------------------------------
/**
* Creates a new peer editing context, typically used to make
* changes outside of a session's editing context.
* @return the new editing context
*/
public static ReadOnlyEditingContext newEditingContext()
{
return (ReadOnlyEditingContext)factory()._newEditingContext();
}
//~ Methods ...............................................................
// ----------------------------------------------------------
@Override
public NSArray<EOEnterpriseObject> objectsWithFetchSpecification(
EOFetchSpecification fspec, EOEditingContext ec)
{
// Augment the qualifier and use that for the original database fetch.
EOFetchSpecification augFspec = (EOFetchSpecification) fspec.clone();
EOQualifier q = fspec.qualifier();
QualifierAugmenter augmenter = new QualifierAugmenter(
fspec.entityName(), q);
augFspec.setQualifier(augmenter.augmentedQualifier());
@SuppressWarnings("unchecked")
NSArray<EOEnterpriseObject> objects =
super.objectsWithFetchSpecification(augFspec, ec);
if (augmenter.isSignificantDifference())
{
// Since the objects have been fetched, this has caused their
// migratory attributes to be populated. We can now filter this
// array in-memory with the original qualifier.
if (!fspec.fetchesRawRows())
{
objects = EOQualifier.filteredArrayWithQualifier(objects, q);
}
}
return objects;
}
// ----------------------------------------------------------
@Override
public void deleteObject(EOEnterpriseObject object)
{
logModificationAttempt(
"deleteObject method called on read-only editing context; " +
"the operation was ignored.");
}
// ----------------------------------------------------------
@Override
public void insertObject(EOEnterpriseObject object)
{
logModificationAttempt(
"insertObject method called on read-only editing context; " +
"the operation was ignored.");
}
// ----------------------------------------------------------
@Override
public void insertObjectWithGlobalID(EOEnterpriseObject object,
EOGlobalID gid)
{
logModificationAttempt(
"insertObjectWithGlobalID method called on read-only " +
"editing context; the operation was ignored.");
}
// ----------------------------------------------------------
@Override
public void saveChanges()
{
logModificationAttempt(
"saveChanges method called on read-only editing context; " +
"the operation was ignored.");
}
// ----------------------------------------------------------
/**
* Gets a value indicating whether a modification attempt was made on this
* editing context. Once this flag has been set by one of the modifying
* methods, it remains set through the lifetime of the editing context and
* can never be cleared.
*
* @return true if an attempt was made to modify the editing context,
* otherwise false.
*/
public boolean modificationWasAttempted()
{
return modificationWasAttempted;
}
// ----------------------------------------------------------
/**
* Logs a modification attempt.
*
* @param message a message describing the modification attempt
*/
private void logModificationAttempt(String message)
{
modificationWasAttempted = true;
if (!loggingSuppressed)
{
log.error(message, new Throwable("called here"));
if (suppressesLogAfterFirstAttempt)
{
setLoggingSuppressed(true);
}
}
}
// ----------------------------------------------------------
/**
* Gets a value indicating whether logging is suppressed.
*
* @return true if suppressed, false if activated
*/
public boolean isLoggingSuppressed()
{
return loggingSuppressed;
}
// ----------------------------------------------------------
/**
* Suppresses logging of modification attempts if true, or reactivates
* logging if false.
*
* @param suppress true to suppress, false to activate
*/
public void setLoggingSuppressed(boolean suppress)
{
loggingSuppressed = suppress;
}
// ----------------------------------------------------------
/**
* Gets a value indicating whether logging should be suppressed after the
* first modification attempt.
*
* @return true if suppressed, false if activated
*/
public boolean suppressesLogAfterFirstAttempt()
{
return suppressesLogAfterFirstAttempt;
}
// ----------------------------------------------------------
/**
* Suppresses logging of modification attempts after the first one if true,
* or logs every modification attempt if false. This acts as a form of
* flood control when the editing context is being used repeatedly, such as
* during report generation.
*
* @param suppress true to suppress after the first attempt, false to
* log all modification attempts
*/
public void setSuppressesLogAfterFirstAttempt(boolean suppress)
{
suppressesLogAfterFirstAttempt = suppress;
}
// ----------------------------------------------------------
public static class ReadOnlyFactory
extends WCECFactory
{
protected EOEditingContext _createEditingContext(EOObjectStore parent)
{
return new ReadOnlyEditingContext(parent == null
? EOEditingContext.defaultParentObjectStore()
: parent);
}
}
// ----------------------------------------------------------
public static Factory factory() {
if (factory == null) {
factory = new ReadOnlyFactory();
}
return factory;
}
//~ Static/instance variables .............................................
private boolean modificationWasAttempted = false;
private boolean loggingSuppressed = false;
private boolean suppressesLogAfterFirstAttempt = false;
private static Factory factory;
static final Logger log = Logger.getLogger(ReadOnlyEditingContext.class);
}