001/*
002 *  Copyright 2010 Anyware Services
003 *
004 *  Licensed under the Apache License, Version 2.0 (the "License");
005 *  you may not use this file except in compliance with the License.
006 *  You may obtain a copy of the License at
007 *
008 *      http://www.apache.org/licenses/LICENSE-2.0
009 *
010 *  Unless required by applicable law or agreed to in writing, software
011 *  distributed under the License is distributed on an "AS IS" BASIS,
012 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 *  See the License for the specific language governing permissions and
014 *  limitations under the License.
015 */
016package org.ametys.web.tags;
017
018import org.ametys.plugins.repository.AmetysRepositoryException;
019import org.ametys.plugins.repository.query.expression.Expression;
020import org.ametys.web.repository.content.jcr.TaggableAmetysObjectHelper;
021
022/**
023 * Constructs an {@link Expression} corresponding to a tag comparison.
024 */
025public class TagExpression implements Expression
026{
027    /** The logical operator to use in xpath query */
028    public enum LogicalOperator 
029    {
030        /** Logical operator AND */
031        AND
032        {
033            @Override
034            public String toString()
035            {
036                return " and ";
037            }
038        },
039        /** Logical operator OR */
040        OR
041        {
042            @Override
043            public String toString()
044            {
045                return " or ";
046            }
047        }
048    }
049    
050    private Operator _operator;
051    private String[] _values;
052    private LogicalOperator _logicalOperator;
053
054    /**
055     * Creates the expression.
056     * @param operator the operator to make the comparison (only Operator.EQ and Operator.NE allowed)
057     * @param value the tag value 
058     */
059    public TagExpression(Operator operator, String value)
060    {
061        if (Operator.EQ != operator && Operator.NE != operator)
062        {
063            throw new AmetysRepositoryException("Test operator '" + "' is unknown for test's expression.");
064        }
065
066        _operator = operator;
067        _values = new String[]{value};
068    }
069    
070    /**
071     * Creates the expression.
072     * @param operator the operator to make the comparison (only Operator.EQ and Operator.NE allowed)
073     * @param values the tags value in a array
074     * @param logicalOperator the logical operator to use for given value
075     */
076    public TagExpression(Operator operator, String[] values, LogicalOperator logicalOperator)
077    {
078        if (Operator.EQ != operator && Operator.NE != operator)
079        {
080            throw new AmetysRepositoryException("Test operator '" + "' is unknown for test's expression.");
081        }
082
083        _operator = operator;
084        _values = values;
085        _logicalOperator = logicalOperator;
086    }
087    
088
089    @Override
090    public String build()
091    {
092        StringBuffer sb = new StringBuffer();
093        if (_values.length > 1)
094        {
095            sb.append("(");
096        }
097        for (int i = 0; i < _values.length; i++)
098        {
099            if (i != 0)
100            {
101                sb.append(_logicalOperator);
102            }
103            sb.append("@" + TaggableAmetysObjectHelper.METADATA_TAGS + " " + _operator + "'" + _values[i].replaceAll("'", "''") + "'");
104        }
105        if (_values.length > 1)
106        {
107            sb.append(")");
108        }
109        
110        return sb.toString();
111    }
112}