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Java > Open Source Codes > com > caucho > amber > expr > ManyToOneSchemaExpr


1 /*
2  * Copyright (c) 1998-2006 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 Software Foundation, 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.expr;
30
31 import com.caucho.amber.field.AmberField;
32 import com.caucho.amber.query.FromItem;
33 import com.caucho.amber.query.QueryParseException;
34 import com.caucho.amber.query.QueryParser;
35 import com.caucho.amber.type.RelatedType;
36 import com.caucho.util.L10N;
37
38 /**
39  * Represents a collection from a from-item table.
40  */
41 public class ManyToOneSchemaExpr extends SchemaExpr {
42   private static final L10N L = new L10N(CollectionSchemaExpr.class);
43
44   private ManyToOneExpr _expr;
45   private String JavaDoc _name;
46
47   /**
48    * Creates the collection schema.
49    */
50   public ManyToOneSchemaExpr(ManyToOneExpr expr, String JavaDoc name)
51   {
52     _expr = expr;
53     _name = name;
54   }
55
56   /**
57    * Returns the tail name.
58    */
59   public String JavaDoc getTailName()
60   {
61     return _name;
62   }
63
64   /**
65    * Creates a field-based schema.
66    */
67   public SchemaExpr createField(QueryParser parser, String JavaDoc name)
68     throws QueryParseException
69   {
70     RelatedType type = _expr.getTargetType();
71
72     AmberField field = type.getField(name);
73
74     if (field == null)
75       throw parser.error(L.l("{0}: '{1}' is an unknown field.",
76                              type.getBeanClass().getName(),
77                              name));
78
79     AmberExpr fieldExpr = _expr.createField(parser, name);
80
81     if (fieldExpr instanceof ManyToOneExpr)
82       return new ManyToOneSchemaExpr((ManyToOneExpr) fieldExpr, name);
83     /*
84       else if (fieldExpr instanceof ManyToManyExpr)
85       return new ManyToManySchemaExpr((ManyToManyExpr) fieldExpr);
86     */
87     else if (fieldExpr instanceof OneToManyExpr)
88       return new OneToManySchemaExpr((OneToManyExpr) fieldExpr);
89     throw parser.error(L.l("{0}: '{1}' must be a collection.",
90                            type.getBeanClass().getName(),
91                            name));
92   }
93
94   /**
95    * Adds the from item.
96    */
97   public FromItem addFromItem(QueryParser parser, String JavaDoc id)
98     throws QueryParseException
99   {
100     _expr = (ManyToOneExpr) _expr.bindSelect(parser, id);
101
102     FromItem fromItem = _expr.bindSubPath(parser);
103
104     return fromItem;
105   }
106 }
107
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