/*
* Copyright 2012 The Solmix Project
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software 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
* Lesser General Public License for more details.
*
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
* http://www.gnu.org/licenses/
* or see the FSF site: http://www.fsf.org.
*/
package org.solmix.fmk.velocity;
import java.util.ArrayList;
import java.util.List;
import org.apache.velocity.app.event.EventCartridge;
import org.apache.velocity.app.event.ReferenceInsertionEventHandler;
import org.apache.velocity.context.Context;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.solmix.api.datasource.DataSource;
/**
* Reference 'Stream insertion' event handler. Called with object that will be inserted into stream via
* value.toString(). Please return an Object that will toString() nicely :)
*
* @author solmix.f@gmail.com
* @since 0.0.1
* @version 110046
*/
public class DSReferenceInsertionEventHandler implements ReferenceInsertionEventHandler
{
private static final String ESCAPING_EXCEPTIONS[] = { "$defaultSelectClause", "$defaultTableClause", "$defaultWhereClause",
"$defaultValuesClause", "$criteria", "$values", "$defaultGroupClause", "$defaultGroupWhereClause", "$defaultOrderClause", "$rawValue",
"$filter", "$equals", "$substringMatches", "$fields", "$qfields" };
private static Logger log = LoggerFactory.getLogger(DSReferenceInsertionEventHandler.class.getName());
private final boolean escapeValues;
private final DataSource ds;
private final List<String> externals;
public Object foundObject;
public DSReferenceInsertionEventHandler(Context ctx)
{
this(ctx, null, false);
}
public DSReferenceInsertionEventHandler(Context ctx, DataSource ds, boolean escapeValues)
{
externals = new ArrayList<String>();
this.escapeValues = escapeValues;
this.ds = ds;
EventCartridge ec = new EventCartridge();
ec.addEventHandler(this);
ec.attachToContext(ctx);
Object keys[] = ctx.getKeys();
for (int i = 0; i < keys.length; i++)
externals.add(keys[i].toString());
}
/**
* A call-back which is executed during Velocity merge before a reference value is inserted into the output stream.
* All registered ReferenceInsertionEventHandlers are called in sequence. If no ReferenceInsertionEventHandlers are
* are registered then reference value is inserted into the output stream as is.
* <p>
* note: this javadoc is from velocity javadoc for convenience.
*
* @param reference Reference from template about to be inserted.
* @param data Value about to be inserted (after its toString() method is called).
* @return Object on which toString() should be called for output
*/
@Override
public Object referenceInsert(String reference, Object data) {
foundObject = data;
if (escapeValues && ds == null) {
log.warn("getParameter() called but DataSource has not been set - returning warning");
return (new StringBuilder()).append("'Unsafe to retrieve ").append(reference).append(" - DataSource has not been set'").toString();
}
if (escapeValues) {
for (int i = 0; i < ESCAPING_EXCEPTIONS.length; i++)
if (reference.equals(ESCAPING_EXCEPTIONS[i])
|| reference.startsWith((new StringBuilder()).append(ESCAPING_EXCEPTIONS[i]).append(".").toString())) {
return data;
}
boolean escape = false;
for (String str : externals) {
String external = (new StringBuilder()).append("$").append(str).toString();
if (reference.equals(external) || reference.startsWith(external + ".")) {
escape = true;
break;
}
}
if (!escape)
return ds.escapeValue(data, reference);
else
return data;
} else {
return data;
}
}
}