// Copyright 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.hivemind.schema.rules;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hivemind.ApplicationRuntimeException;
import org.apache.hivemind.Element;
import org.apache.hivemind.ErrorHandler;
import org.apache.hivemind.HiveMind;
import org.apache.hivemind.internal.Module;
import org.apache.hivemind.schema.SchemaProcessor;
import org.apache.hivemind.schema.Translator;
import org.apache.hivemind.util.PropertyUtils;
/**
* Static methods useful to {@link org.apache.hivemind.schema.Rule}s and
* {@link org.apache.hivemind.schema.Translator}s.
*
* @author Howard Lewis Ship
*/
public class RuleUtils
{
private static final Log LOG = LogFactory.getLog(RuleUtils.class);
/**
* Used to convert a {@link org.apache.hivemind.schema.Translator}
* initializer string of the form:
* <code><i>key</i>=<i>value</i>[,<i>key</i>=<i>value<i>]*</code>
* into a Map of keys and values. The keys and values are Strings.
*/
public static Map convertInitializer(String initializer)
{
if (HiveMind.isBlank(initializer))
return Collections.EMPTY_MAP;
Map result = new HashMap();
int lastCommax = -1;
int inputLength = initializer.length();
while (lastCommax < inputLength)
{
int nextCommax = initializer.indexOf(',', lastCommax + 1);
if (nextCommax < 0)
nextCommax = inputLength;
String term = initializer.substring(lastCommax + 1, nextCommax);
int equalsx = term.indexOf('=');
if (equalsx <= 0)
throw new ApplicationRuntimeException(
RulesMessages.invalidInitializer(initializer));
String key = term.substring(0, equalsx);
String value = term.substring(equalsx + 1);
result.put(key, value);
lastCommax = nextCommax;
}
return result;
}
/**
* Invoked to process text from an attribute or from an element's content. Performs
* two jobs:
* <ul>
* <li>Convert localized message references to localized strings
* <li>Expand symbols using {@link Registry#expandSymbols(String, Location)}
* </ul>
*
* <p>
* Note: if the input is a localized message then no symbol expansion takes place.
* Localized message references are simply strings that begin with '%'. The remainder
* of the string is the message key.
*
* <p>
* A null input value passes through unchanged.
*/
public static String processText(SchemaProcessor processor, Element element, String inputValue)
{
if (inputValue == null)
return null;
Module contributingModule = processor.getContributingModule();
if (inputValue.startsWith("%"))
{
String key = inputValue.substring(1);
return contributingModule.getMessages().getMessage(key);
}
return contributingModule.expandSymbols(inputValue, element.getLocation());
}
/**
* Sets a property of the target object to the given value.
* Logs an error if there is a problem.
*/
public static void setProperty(
SchemaProcessor processor,
Element element,
String propertyName,
Object target,
Object value)
{
try
{
PropertyUtils.write(target, propertyName, value);
}
catch (Exception ex)
{
// Have to decide if we need to display the location of the rule
// or the element.
ErrorHandler errorHandler = processor.getContributingModule().getErrorHandler();
errorHandler.error(
LOG,
RulesMessages.unableToSetElementProperty(
propertyName,
target,
processor,
element,
ex),
element.getLocation(),
ex);
}
}
/**
* Convienience for invoking
* {@link Module#getTranslator(String)}.
*
* @param processor the processor for the schema being converted
* @param translator the string identifying the translator to provide (may be null)
* @return a translator obtained via the contributing module, or an
* instance of {@link NullTranslator}
*/
public static Translator getTranslator(SchemaProcessor processor, String translator)
{
if (translator == null)
return new NullTranslator();
return processor.getContributingModule().getTranslator(translator);
}
}