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Java > Open Source Codes > com > caucho > amber > query > AbstractPathExpr


1 /*
2  * Copyright (c) 1998-2004 Caucho Technology -- all rights reserved
3  *
4  * This file is part of Resin(R) Open Source
5  *
6  * Each copy or derived work must preserve the copyright notice and this
7  * notice unmodified.
8  *
9  * Resin Open Source is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License as published by
11  * the Free Software Foundation; either version 2 of the License, or
12  * (at your option) any later version.
13  *
14  * Resin Open Source is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, or any warranty
17  * of NON-INFRINGEMENT. See the GNU General Public License for more
18  * details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with Resin Open Source; if not, write to the
22  * Free SoftwareFoundation, Inc.
23  * 59 Temple Place, Suite 330
24  * Boston, MA 02111-1307 USA
25  *
26  * @author Scott Ferguson
27  */
28
29 package com.caucho.amber.query;
30
31 import com.caucho.util.L10N;
32
33 import com.caucho.amber.AmberRuntimeException;
34
35 import com.caucho.amber.field.AmberField;
36
37 /**
38  * Represents an amber mapping query expression
39  */
40 abstract public class AbstractPathExpr extends AbstractAmberExpr
41   implements PathExpr {
42   private static final L10N L = new L10N(AbstractPathExpr.class);
43   
44   /**
45    * Creates the expr from the path.
46    */
47   public AmberExpr createField(QueryParser parser, String fieldName)
48   {
49     AmberField field = getTargetType().getField(fieldName);
50
51     if (field == null)
52       throw new AmberRuntimeException(L.l("'{0}' is an unknown field of '{1}'.",
53                       fieldName, getTargetType().getName()));
54
55     return field.createExpr(parser, this);
56   }
57   
58   /**
59    * Creates an array reference.
60    */
61   public AmberExpr createArray(AmberExpr field)
62   {
63     throw new UnsupportedOperationException(getClass().getName());
64   }
65
66   /**
67    * Binds the expression as a select item.
68    */
69   public PathExpr bindSelect(QueryParser parser, String tableName)
70   {
71     return this;
72   }
73
74   /**
75    * Binds the expression as a select item.
76    */
77   public FromItem bindSubPath(QueryParser parser)
78   {
79     return null;
80   }
81   
82   /**
83    * Returns the from item
84    */
85   public FromItem getChildFromItem()
86   {
87     throw new UnsupportedOperationException(getClass().getName());
88   }
89 }
90
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