| Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
| TypeDirective |
|
| 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 |