001package org.apache.commons.digester3.binder;
002
003/*
004 * Licensed to the Apache Software Foundation (ASF) under one
005 * or more contributor license agreements.  See the NOTICE file
006 * distributed with this work for additional information
007 * regarding copyright ownership.  The ASF licenses this file
008 * to you under the Apache License, Version 2.0 (the
009 * "License"); you may not use this file except in compliance
010 * with the License.  You may obtain a copy of the License at
011 *
012 *   http://www.apache.org/licenses/LICENSE-2.0
013 *
014 * Unless required by applicable law or agreed to in writing,
015 * software distributed under the License is distributed on an
016 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
017 * KIND, either express or implied.  See the License for the
018 * specific language governing permissions and limitations
019 * under the License.
020 */
021
022/**
023 * A support class for RulesModule which reduces repetition and results in a more readable configuration.
024 *
025 * @since 3.0
026 */
027public abstract class AbstractRulesModule
028    implements RulesModule
029{
030
031    private RulesBinder rulesBinder;
032
033    /**
034     * {@inheritDoc}
035     */
036    public final void configure( RulesBinder rulesBinder )
037    {
038        if ( this.rulesBinder != null )
039        {
040            throw new IllegalStateException( "Re-entry is not allowed." );
041        }
042
043        this.rulesBinder = rulesBinder;
044        try
045        {
046            configure();
047        }
048        finally
049        {
050            this.rulesBinder = null;
051        }
052    }
053
054    /**
055     * Configures a {@link RulesBinder} via the exposed methods.
056     */
057    protected abstract void configure();
058
059    /**
060     * Records an error message which will be presented to the user at a later time.
061     *
062     * Uses {@link java.lang.String#format(String, Object...)} to insert the arguments into the message.
063     *
064     * @param messagePattern A
065     *        <a href="http://download.oracle.com/javase/6/docs/api/java/util/Formatter.html#syntax">format string</a>
066     * @param arguments Arguments referenced by the format specifiers in the format string
067     * @see RulesBinder#addError(String, Object...)
068     */
069    protected void addError( String messagePattern, Object... arguments )
070    {
071        rulesBinder.addError( messagePattern, arguments );
072    }
073
074    /**
075     * Records an exception, the full details of which will be logged, and the message of which will be presented to
076     * the user at a later time.
077     *
078     * @param t The exception has to be recorded
079     * @see RulesBinder#addError(Throwable)
080     */
081    protected void addError( Throwable t )
082    {
083        rulesBinder.addError( t );
084    }
085
086    /**
087     * Uses the given module to configure more bindings.
088     *
089     * @param rulesModule The module used to configure more bindings
090     * @see RulesBinder#install(RulesModule)
091     */
092    protected void install( RulesModule rulesModule )
093    {
094        rulesBinder.install( rulesModule );
095    }
096
097    /**
098     * Allows user binding one or more Digester rules to the input pattern.
099     *
100     * @param pattern The pattern used to bind rules
101     * @return The Digester rules builder
102     * @see RulesBinder#forPattern(String)
103     */
104    protected LinkedRuleBuilder forPattern( String pattern )
105    {
106        return rulesBinder.forPattern( pattern );
107    }
108
109    /**
110     * Return the wrapped {@link RulesBinder}.
111     *
112     * @return The wrapped {@link RulesBinder}
113     */
114    protected RulesBinder rulesBinder()
115    {
116        return rulesBinder;
117    }
118
119}