Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
TypeDirective |
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| 3.142857142857143;3.143 |
1 | /* | |
2 | * Copyright (C) 1998-2000 Semiotek Inc. All Rights Reserved. | |
3 | * | |
4 | * Redistribution and use in source and binary forms, with or without | |
5 | * modification, are permitted under the terms of either of the following | |
6 | * Open Source licenses: | |
7 | * | |
8 | * The GNU General Public License, version 2, or any later version, as | |
9 | * published by the Free Software Foundation | |
10 | * (http://www.fsf.org/copyleft/gpl.html); | |
11 | * | |
12 | * or | |
13 | * | |
14 | * The Semiotek Public License (http://webmacro.org/LICENSE.) | |
15 | * | |
16 | * This software is provided "as is", with NO WARRANTY, not even the | |
17 | * implied warranties of fitness to purpose, or merchantability. You | |
18 | * assume all risks and liabilities associated with its use. | |
19 | * | |
20 | * See www.webmacro.org for more information on the WebMacro project. | |
21 | */ | |
22 | package org.webmacro.directive; | |
23 | ||
24 | import java.io.IOException; | |
25 | ||
26 | import org.webmacro.Broker; | |
27 | import org.webmacro.Context; | |
28 | import org.webmacro.FastWriter; | |
29 | import org.webmacro.Macro; | |
30 | import org.webmacro.PropertyException; | |
31 | import org.webmacro.TemplateVisitor; | |
32 | import org.webmacro.engine.BuildContext; | |
33 | import org.webmacro.engine.BuildException; | |
34 | import org.webmacro.engine.UndefinedMacro; | |
35 | import org.webmacro.engine.Variable; | |
36 | import org.webmacro.util.Settings; | |
37 | ||
38 | /** | |
39 | * TypeDirective allows the programmer (or template designer) to ensure | |
40 | * objects placed into the <code>Context</code> are of the required class | |
41 | * type. | |
42 | * <p> | |
43 | * Syntax: | |
44 | * <pre> | |
45 | * #type [ required ] var-reference quoted-string | |
46 | * </pre> | |
47 | * | |
48 | * Examples: | |
49 | * <pre> | |
50 | * $MyName, if it exists in the context, <b>must</b> be a java.lang.String | |
51 | * #type $MyName "java.lang.String" | |
52 | * | |
53 | * $Today <b>must</b> exist in the context and <b>must</b> be a java.util.Date | |
54 | * #type required $Today "java.util.Date" | |
55 | * | |
56 | * $Addresses, if it exists in the context, <b>must</b> be an org.mycompany.til.Address array | |
57 | * #type $Addresses "org.mycompany.util.Address[]" | |
58 | * </pre> | |
59 | * | |
60 | * TypeDirective simply ensures the class type of the <code>$Variable</code> | |
61 | * <code>isAssignableFrom</code> the specified classname.<p> | |
62 | * | |
63 | * If the variable is not flagged as being <i>required</i>, then its class type | |
64 | * is only checked if it exists in the context. By default, variables are not | |
65 | * required to be in the context.<p> | |
66 | * | |
67 | * Special support for checking that a variable is an object array exists. | |
68 | * Simply append matching square brackets to the end of the classname.<p> | |
69 | * | |
70 | * If a Variable is <b>not</b> of the specified type, TypeDirective will | |
71 | * throw a <code>org.webmacro.PropertyException.InvalidTypeException</code>, | |
72 | * which one can catch in their servlet code if necessary.<p> | |
73 | * | |
74 | * TypeDirective is <b>enabled by default</b>, however, it can be disabled | |
75 | * via your custom <code>WebMacro.properties</code> file: | |
76 | * <pre> | |
77 | * TypeDirective.Enabled = true | false | |
78 | * </pre> | |
79 | * | |
80 | * @author <a href=mailto:ebr@tcdi.com>Eric B. Ridge</a> | |
81 | * @version 1.0 | |
82 | * @since post 0.97 | |
83 | */ | |
84 | 0 | public class TypeDirective extends Directive |
85 | { | |
86 | ||
87 | public static final int TYPE_REQUIRED = 0; | |
88 | public static final int TYPE_OBJECT = 1; | |
89 | public static final int TYPE_CLASSNAME = 2; | |
90 | ||
91 | 2 | public static final ArgDescriptor[] _args = new ArgDescriptor[]{ |
92 | new OptionalGroup(1), | |
93 | new KeywordArg(TYPE_REQUIRED, "required"), | |
94 | new RValueArg(TYPE_OBJECT), | |
95 | new QuotedStringArg(TYPE_CLASSNAME), | |
96 | }; | |
97 | ||
98 | 2 | public static final DirectiveDescriptor _dd = |
99 | new DirectiveDescriptor("type", null, _args, null); | |
100 | ||
101 | /** | |
102 | * Static method required by the WebMacro parser to provide | |
103 | * a descriptor about this directive. | |
104 | */ | |
105 | public static DirectiveDescriptor getDescriptor () | |
106 | { | |
107 | 6 | return _dd; |
108 | } | |
109 | ||
110 | ||
111 | /** The Context object we need to check the type of. */ | |
112 | private Variable _object; | |
113 | ||
114 | /** The Class instance that _object is requried to be. */ | |
115 | private Class _class; | |
116 | ||
117 | /** Is the Variable required to be in the Context? */ | |
118 | private boolean _required; | |
119 | ||
120 | /** | |
121 | * Configure directive for this run and return 'this'. | |
122 | */ | |
123 | public Object build (DirectiveBuilder builder, BuildContext bc) throws BuildException | |
124 | { | |
125 | ||
126 | 0 | if (!isEnabled(builder.getName(), bc.getBroker())) |
127 | 0 | return null; |
128 | ||
129 | 0 | String classname = (String) builder.getArg(TYPE_CLASSNAME, bc); |
130 | 0 | _object = (Variable) builder.getArg(TYPE_OBJECT, bc); |
131 | 0 | _required = builder.getArg(TYPE_REQUIRED, bc) != null; |
132 | ||
133 | try | |
134 | { | |
135 | 0 | _class = TypeDirective.getClass(classname); |
136 | } | |
137 | 0 | catch (ClassNotFoundException cnfe) |
138 | { | |
139 | 0 | throw new BuildException("TypeDirective cannot find the class " |
140 | + "/" + classname + "/"); | |
141 | 0 | } |
142 | ||
143 | 0 | return this; |
144 | } | |
145 | ||
146 | /** | |
147 | * Ensure the class of the specified Variable reference | |
148 | * <code>isAssignableFrom</code> from the classname arg. | |
149 | * | |
150 | * @return <code>null</code>, always | |
151 | * @throws PropertyException.NoSuchVariableException if the | |
152 | * specified variable arg evaluates to null | |
153 | */ | |
154 | public Object evaluate (Context context) throws PropertyException | |
155 | { | |
156 | 0 | Object o = _object; |
157 | ||
158 | // evaluate the _object reference down to its base object | |
159 | 0 | while (o instanceof Macro && o != UndefinedMacro.getInstance()) |
160 | 0 | o = ((Macro) o).evaluate(context); |
161 | ||
162 | 0 | if (o == null || o == UndefinedMacro.getInstance()) |
163 | { | |
164 | // the Variable to check isn't in the Context. | |
165 | 0 | if (_required) |
166 | { | |
167 | // but it should be | |
168 | 0 | throw new PropertyException |
169 | .NoSuchVariableException(_object.getName()); | |
170 | } | |
171 | else | |
172 | { | |
173 | // but it's not required to be there, so get out now | |
174 | // can't check the type of a null object | |
175 | 0 | return null; |
176 | } | |
177 | } | |
178 | ||
179 | // check it and throw if requried class isn't compatible | |
180 | // with class of specified object | |
181 | 0 | if (!_class.isAssignableFrom(o.getClass())) |
182 | 0 | throw new PropertyException.InvalidTypeException(_object.getName(), |
183 | _class); | |
184 | ||
185 | 0 | return null; |
186 | } | |
187 | ||
188 | /** | |
189 | * The #type directive does not produce output. | |
190 | */ | |
191 | public void write (FastWriter fw, Context context) throws IOException, PropertyException | |
192 | { | |
193 | 0 | evaluate(context); |
194 | 0 | } |
195 | ||
196 | public void accept (TemplateVisitor v) | |
197 | { | |
198 | 0 | v.beginDirective(_dd.name); |
199 | 0 | v.visitDirectiveArg("TypeContextObject", _object); |
200 | 0 | v.visitDirectiveArg("TypeClassname", _class.getName()); |
201 | 0 | v.endDirective(); |
202 | 0 | } |
203 | ||
204 | /** | |
205 | * Check the configuration and see if we're enabled or not. By default, we | |
206 | * are <b>enabled</b>, even if the configuration key doesn't exist. | |
207 | */ | |
208 | private final boolean isEnabled (String directiveName, Broker broker) | |
209 | { | |
210 | 0 | Settings s = broker.getSettings(); |
211 | 0 | return s.getBooleanSetting(directiveName + ".Enabled", true); |
212 | } | |
213 | ||
214 | // | |
215 | // private, static methods | |
216 | // | |
217 | ||
218 | /** | |
219 | * Use specified class name to return its Class instance. special support | |
220 | * for an alternate syntax for object arrays:<pre> | |
221 | * java.util.Date[] -- a 1d array of Date objects | |
222 | * java.util.Data[][] -- a 2d array of Date objects | |
223 | * </pre> | |
224 | */ | |
225 | private static final Class getClass (final String classname) throws ClassNotFoundException | |
226 | { | |
227 | Class clazz; | |
228 | ||
229 | 0 | if (classname.endsWith("[]")) |
230 | { | |
231 | // an object array of some kind | |
232 | 0 | String newName = "[L" + classname.substring(0, classname.length() - 2); |
233 | 0 | if (classname.endsWith("[][]")) // support 2d arrays |
234 | 0 | newName = "[" + newName.substring(0, newName.length() - 2); |
235 | 0 | newName += ";"; |
236 | ||
237 | 0 | clazz = Class.forName(newName); |
238 | 0 | } |
239 | else | |
240 | { | |
241 | // a normal object | |
242 | 0 | clazz = Class.forName(classname); |
243 | } | |
244 | ||
245 | 0 | return clazz; |
246 | } | |
247 | } | |
248 |