1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing,
13 * software distributed under the License is distributed on an
14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15 * KIND, either express or implied. See the License for the
16 * specific language governing permissions and limitations
17 * under the License.
18 */
19 package javax.faces.view.facelets;
20
21 import javax.el.MethodExpression;
22 import javax.el.ValueExpression;
23 import javax.faces.view.Location;
24
25 /**
26 * Representation of a Tag's attribute in a Facelet File
27 */
28 public abstract class TagAttribute
29 {
30 public TagAttribute()
31 {
32
33 }
34
35 /**
36 * If literal, return {@link Boolean#getBoolean(java.lang.String) Boolean.getBoolean(java.lang.String)} passing our
37 * value, otherwise call {@link #getObject(FaceletContext, Class) getObject(FaceletContext, Class)}.
38 *
39 * @see Boolean#getBoolean(java.lang.String)
40 * @see #getObject(FaceletContext, Class)
41 * @param ctx
42 * FaceletContext to use
43 * @return boolean value
44 */
45 public abstract boolean getBoolean(FaceletContext ctx);
46
47 /**
48 * If literal, call {@link Integer#parseInt(java.lang.String) Integer.parseInt(String)}, otherwise call
49 * {@link #getObject(FaceletContext, Class) getObject(FaceletContext, Class)}.
50 *
51 * @see Integer#parseInt(java.lang.String)
52 * @see #getObject(FaceletContext, Class)
53 * @param ctx
54 * FaceletContext to use
55 * @return int value
56 */
57 public abstract int getInt(FaceletContext ctx);
58
59 /**
60 * Local name of this attribute
61 *
62 * @return local name of this attribute
63 */
64 public abstract String getLocalName();
65
66 /**
67 * The location of this attribute in the FaceletContext
68 *
69 * @return the TagAttribute's location
70 */
71 public abstract Location getLocation();
72
73 /**
74 * Create a MethodExpression, using this attribute's value as the expression String.
75 *
76 * @see javax.el.ExpressionFactory#createMethodExpression(javax.el.ELContext, java.lang.String, java.lang.Class,
77 * java.lang.Class[])
78 * @see MethodExpression
79 * @param ctx
80 * FaceletContext to use
81 * @param type
82 * expected return type
83 * @param paramTypes
84 * parameter type
85 * @return a MethodExpression instance
86 */
87 public abstract MethodExpression getMethodExpression(FaceletContext ctx, Class type, Class[] paramTypes);
88
89 /**
90 * The resolved Namespace for this attribute
91 *
92 * @return resolved Namespace
93 */
94 public abstract String getNamespace();
95
96 /**
97 * Delegates to getObject with Object.class as a param
98 *
99 * @see #getObject(FaceletContext, Class)
100 * @param ctx
101 * FaceletContext to use
102 * @return Object representation of this attribute's value
103 */
104 public abstract Object getObject(FaceletContext ctx);
105
106 /**
107 * If literal, simply coerce our String literal value using an ExpressionFactory, otherwise create a ValueExpression
108 * and evaluate it.
109 *
110 * @see javax.el.ExpressionFactory#coerceToType(java.lang.Object, java.lang.Class)
111 * @see javax.el.ExpressionFactory#createValueExpression(javax.el.ELContext, java.lang.String, java.lang.Class)
112 * @see ValueExpression
113 * @param ctx
114 * FaceletContext to use
115 * @param type
116 * expected return type
117 * @return Object value of this attribute
118 */
119 public abstract Object getObject(FaceletContext ctx, Class type);
120
121 /**
122 * The qualified name for this attribute
123 *
124 * @return the qualified name for this attribute
125 */
126 public abstract String getQName();
127
128 /**
129 * Return the literal value of this attribute
130 *
131 * @return literal value
132 */
133 public abstract String getValue();
134
135 /**
136 * If literal, then return our value, otherwise delegate to getObject, passing String.class.
137 *
138 * @see #getObject(FaceletContext, Class)
139 * @param ctx
140 * FaceletContext to use
141 * @return String value of this attribute
142 */
143 public abstract String getValue(FaceletContext ctx);
144
145 /**
146 * Create a ValueExpression, using this attribute's literal value and the passed expected type.
147 *
148 * @see javax.el.ExpressionFactory#createValueExpression(javax.el.ELContext, java.lang.String, java.lang.Class)
149 * @see ValueExpression
150 * @param ctx
151 * FaceletContext to use
152 * @param type
153 * expected return type
154 * @return ValueExpression instance
155 */
156 public abstract ValueExpression getValueExpression(FaceletContext ctx, Class type);
157
158 /**
159 * If this TagAttribute is literal (not #{..} or ${..})
160 *
161 * @return true if this attribute is literal
162 */
163 public abstract boolean isLiteral();
164
165 /**
166 * @since 2.2
167 * @return
168 */
169 public Tag getTag()
170 {
171 return null;
172 }
173
174 /**
175 * @since 2.2
176 * @param tag
177 */
178 public void setTag(Tag tag)
179 {
180 }
181 }