Source code: com/sun/facelets/tag/jsf/ConvertHandler.java
1 /**
2 * Licensed under the Common Development and Distribution License,
3 * you may not use this file except in compliance with the License.
4 * You may obtain a copy of the License at
5 *
6 * http://www.sun.com/cddl/
7 *
8 * Unless required by applicable law or agreed to in writing, software
9 * distributed under the License is distributed on an "AS IS" BASIS,
10 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
11 * implied. See the License for the specific language governing
12 * permissions and limitations under the License.
13 */
14
15 package com.sun.facelets.tag.jsf;
16
17 import java.io.IOException;
18
19 import javax.el.ELException;
20 import javax.el.ValueExpression;
21 import javax.faces.FacesException;
22 import javax.faces.component.UIComponent;
23 import javax.faces.component.ValueHolder;
24 import javax.faces.context.FacesContext;
25 import javax.faces.convert.Converter;
26
27 import com.sun.facelets.FaceletContext;
28 import com.sun.facelets.FaceletException;
29 import com.sun.facelets.tag.MetaTagHandler;
30 import com.sun.facelets.tag.TagAttribute;
31 import com.sun.facelets.tag.TagConfig;
32 import com.sun.facelets.tag.TagException;
33 import com.sun.facelets.tag.MetaRuleset;
34
35 /**
36 * Handles setting a Converter instance on a ValueHolder. Will wire all
37 * attributes set to the Converter instance created/fetched. Uses the "binding"
38 * attribute for grabbing instances to apply attributes to. <p/> Will only
39 * set/create Converter is the passed UIComponent's parent is null, signifying
40 * that it wasn't restored from an existing tree.
41 *
42 * @see javax.faces.webapp.ConverterELTag
43 * @see javax.faces.convert.Converter
44 * @see javax.faces.component.ValueHolder
45 * @author Jacob Hookom
46 * @version $Id: ConvertHandler.java,v 1.3 2005/08/24 04:38:51 jhook Exp $
47 */
48 public class ConvertHandler extends MetaTagHandler {
49
50 private final TagAttribute binding;
51
52 private String converterId;
53
54 /**
55 * @param config
56 * @deprecated
57 */
58 public ConvertHandler(TagConfig config) {
59 super(config);
60 this.binding = this.getAttribute("binding");
61 this.converterId = null;
62 }
63
64 public ConvertHandler(ConverterConfig config) {
65 this((TagConfig) config);
66 this.converterId = config.getConverterId();
67 }
68
69 /**
70 * Set Converter instance on parent ValueHolder if it's not being restored.
71 * <ol>
72 * <li>Cast to ValueHolder</li>
73 * <li>If "binding" attribute was specified, fetch/create and re-bind to
74 * expression.</li>
75 * <li>Otherwise, call
76 * {@link #createConverter(FaceletContext) createConverter}.</li>
77 * <li>Call
78 * {@link ObjectHandler#setAttributes(FaceletContext, Object) setAttributes}
79 * on Converter instance.</li>
80 * <li>Set the Converter on the ValueHolder</li>
81 * <li>If the ValueHolder has a localValue, convert it and set the value</li>
82 * </ol>
83 *
84 * @see ValueHolder
85 * @see Converter
86 * @see #createConverter(FaceletContext)
87 * @see com.sun.facelets.FaceletHandler#apply(com.sun.facelets.FaceletContext,
88 * javax.faces.component.UIComponent)
89 */
90 public final void apply(FaceletContext ctx, UIComponent parent)
91 throws IOException, FacesException, FaceletException, ELException {
92 if (parent == null || !(parent instanceof ValueHolder)) {
93 throw new TagException(this.tag,
94 "Parent not an instance of ValueHolder: " + parent);
95 }
96
97 // only process if it's been created
98 if (parent.getParent() == null) {
99 // cast to a ValueHolder
100 ValueHolder vh = (ValueHolder) parent;
101 ValueExpression ve = null;
102 Converter c = null;
103 if (this.binding != null) {
104 ve = this.binding.getValueExpression(ctx, Converter.class);
105 c = (Converter) ve.getValue(ctx);
106 }
107 if (c == null) {
108 c = this.createConverter(ctx);
109 if (ve != null) {
110 ve.setValue(ctx, c);
111 }
112 }
113 if (c == null) {
114 throw new TagException(this.tag, "No Converter was created");
115 }
116 this.setAttributes(ctx, c);
117 vh.setConverter(c);
118 Object lv = vh.getLocalValue();
119 FacesContext faces = ctx.getFacesContext();
120 if (lv instanceof String) {
121 vh.setValue(c.getAsObject(faces, parent, (String) lv));
122 }
123 }
124 }
125
126 /**
127 * Create a Converter instance
128 *
129 * @param ctx
130 * FaceletContext to use
131 * @return Converter instance, cannot be null
132 */
133 protected Converter createConverter(FaceletContext ctx) {
134 if (this.converterId == null) {
135 throw new TagException(
136 this.tag,
137 "Default behavior invoked of requiring a converter-id passed in the constructor, must override ConvertHandler(ConverterConfig)");
138 }
139 return ctx.getFacesContext().getApplication().createConverter(this.converterId);
140 }
141
142 protected MetaRuleset createMetaRuleset(Class type) {
143 return super.createMetaRuleset(type).ignore("binding");
144 }
145 }