J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2005 Sun Microsystems, Inc. All Rights Reserved. |
| 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 4 | * |
| 5 | * This code is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License version 2 only, as |
| 7 | * published by the Free Software Foundation. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun in the LICENSE file that accompanied this code. |
| 10 | * |
| 11 | * This code is distributed in the hope that it will be useful, but WITHOUT |
| 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 14 | * version 2 for more details (a copy is included in the LICENSE file that |
| 15 | * accompanied this code). |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License version |
| 18 | * 2 along with this work; if not, write to the Free Software Foundation, |
| 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| 20 | * |
| 21 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | |
| 26 | package com.sun.script.javascript; |
| 27 | |
| 28 | import sun.org.mozilla.javascript.internal.*; |
| 29 | import java.util.*; |
| 30 | |
| 31 | /** |
| 32 | * JSAdapter is java.lang.reflect.Proxy equivalent for JavaScript. JSAdapter |
| 33 | * calls specially named JavaScript methods on an adaptee object when property |
| 34 | * access is attempted on it. |
| 35 | * |
| 36 | * Example: |
| 37 | * |
| 38 | * var y = { |
| 39 | * __get__ : function (name) { ... } |
| 40 | * __has__ : function (name) { ... } |
| 41 | * __put__ : function (name, value) {...} |
| 42 | * __delete__ : function (name) { ... } |
| 43 | * __getIds__ : function () { ... } |
| 44 | * }; |
| 45 | * |
| 46 | * var x = new JSAdapter(y); |
| 47 | * |
| 48 | * x.i; // calls y.__get__ |
| 49 | * i in x; // calls y.__has__ |
| 50 | * x.p = 10; // calls y.__put__ |
| 51 | * delete x.p; // calls y.__delete__ |
| 52 | * for (i in x) { print(i); } // calls y.__getIds__ |
| 53 | * |
| 54 | * If a special JavaScript method is not found in the adaptee, then JSAdapter |
| 55 | * forwards the property access to the adaptee itself. |
| 56 | * |
| 57 | * JavaScript caller of adapter object is isolated from the fact that |
| 58 | * the property access/mutation/deletion are really calls to |
| 59 | * JavaScript methods on adaptee. Use cases include 'smart' |
| 60 | * properties, property access tracing/debugging, encaptulation with |
| 61 | * easy client access - in short JavaScript becomes more "Self" like. |
| 62 | * |
| 63 | * Note that Rhino already supports special properties like __proto__ |
| 64 | * (to set, get prototype), __parent__ (to set, get parent scope). We |
| 65 | * follow the same double underscore nameing convention here. Similarly |
| 66 | * the name JSAdapter is derived from JavaAdapter -- which is a facility |
| 67 | * to extend, implement Java classes/interfaces by JavaScript. |
| 68 | * |
| 69 | * @author A. Sundararajan |
| 70 | * @since 1.6 |
| 71 | */ |
| 72 | public final class JSAdapter implements Scriptable, Function { |
| 73 | private JSAdapter(Scriptable obj) { |
| 74 | setAdaptee(obj); |
| 75 | } |
| 76 | |
| 77 | // initializer to setup JSAdapter prototype in the given scope |
| 78 | public static void init(Context cx, Scriptable scope, boolean sealed) |
| 79 | throws RhinoException { |
| 80 | JSAdapter obj = new JSAdapter(cx.newObject(scope)); |
| 81 | obj.setParentScope(scope); |
| 82 | obj.setPrototype(getFunctionPrototype(scope)); |
| 83 | obj.isPrototype = true; |
| 84 | ScriptableObject.defineProperty(scope, "JSAdapter", obj, |
| 85 | ScriptableObject.DONTENUM); |
| 86 | } |
| 87 | |
| 88 | public String getClassName() { |
| 89 | return "JSAdapter"; |
| 90 | } |
| 91 | |
| 92 | public Object get(String name, Scriptable start) { |
| 93 | Function func = getAdapteeFunction(GET_PROP); |
| 94 | if (func != null) { |
| 95 | return call(func, new Object[] { name }); |
| 96 | } else { |
| 97 | start = getAdaptee(); |
| 98 | return start.get(name, start); |
| 99 | } |
| 100 | } |
| 101 | |
| 102 | public Object get(int index, Scriptable start) { |
| 103 | Function func = getAdapteeFunction(GET_PROP); |
| 104 | if (func != null) { |
| 105 | return call(func, new Object[] { new Integer(index) }); |
| 106 | } else { |
| 107 | start = getAdaptee(); |
| 108 | return start.get(index, start); |
| 109 | } |
| 110 | } |
| 111 | |
| 112 | public boolean has(String name, Scriptable start) { |
| 113 | Function func = getAdapteeFunction(HAS_PROP); |
| 114 | if (func != null) { |
| 115 | Object res = call(func, new Object[] { name }); |
| 116 | return Context.toBoolean(res); |
| 117 | } else { |
| 118 | start = getAdaptee(); |
| 119 | return start.has(name, start); |
| 120 | } |
| 121 | } |
| 122 | |
| 123 | public boolean has(int index, Scriptable start) { |
| 124 | Function func = getAdapteeFunction(HAS_PROP); |
| 125 | if (func != null) { |
| 126 | Object res = call(func, new Object[] { new Integer(index) }); |
| 127 | return Context.toBoolean(res); |
| 128 | } else { |
| 129 | start = getAdaptee(); |
| 130 | return start.has(index, start); |
| 131 | } |
| 132 | } |
| 133 | |
| 134 | public void put(String name, Scriptable start, Object value) { |
| 135 | if (start == this) { |
| 136 | Function func = getAdapteeFunction(PUT_PROP); |
| 137 | if (func != null) { |
| 138 | call(func, new Object[] { name, value }); |
| 139 | } else { |
| 140 | start = getAdaptee(); |
| 141 | start.put(name, start, value); |
| 142 | } |
| 143 | } else { |
| 144 | start.put(name, start, value); |
| 145 | } |
| 146 | } |
| 147 | |
| 148 | public void put(int index, Scriptable start, Object value) { |
| 149 | if (start == this) { |
| 150 | Function func = getAdapteeFunction(PUT_PROP); |
| 151 | if( func != null) { |
| 152 | call(func, new Object[] { new Integer(index), value }); |
| 153 | } else { |
| 154 | start = getAdaptee(); |
| 155 | start.put(index, start, value); |
| 156 | } |
| 157 | } else { |
| 158 | start.put(index, start, value); |
| 159 | } |
| 160 | } |
| 161 | |
| 162 | public void delete(String name) { |
| 163 | Function func = getAdapteeFunction(DEL_PROP); |
| 164 | if (func != null) { |
| 165 | call(func, new Object[] { name }); |
| 166 | } else { |
| 167 | getAdaptee().delete(name); |
| 168 | } |
| 169 | } |
| 170 | |
| 171 | public void delete(int index) { |
| 172 | Function func = getAdapteeFunction(DEL_PROP); |
| 173 | if (func != null) { |
| 174 | call(func, new Object[] { new Integer(index) }); |
| 175 | } else { |
| 176 | getAdaptee().delete(index); |
| 177 | } |
| 178 | } |
| 179 | |
| 180 | public Scriptable getPrototype() { |
| 181 | return prototype; |
| 182 | } |
| 183 | |
| 184 | public void setPrototype(Scriptable prototype) { |
| 185 | this.prototype = prototype; |
| 186 | } |
| 187 | |
| 188 | public Scriptable getParentScope() { |
| 189 | return parent; |
| 190 | } |
| 191 | |
| 192 | public void setParentScope(Scriptable parent) { |
| 193 | this.parent = parent; |
| 194 | } |
| 195 | |
| 196 | public Object[] getIds() { |
| 197 | Function func = getAdapteeFunction(GET_PROPIDS); |
| 198 | if (func != null) { |
| 199 | Object val = call(func, new Object[0]); |
| 200 | // in most cases, adaptee would return native JS array |
| 201 | if (val instanceof NativeArray) { |
| 202 | NativeArray array = (NativeArray) val; |
| 203 | Object[] res = new Object[(int)array.getLength()]; |
| 204 | for (int index = 0; index < res.length; index++) { |
| 205 | res[index] = mapToId(array.get(index, array)); |
| 206 | } |
| 207 | return res; |
| 208 | } else if (val instanceof NativeJavaArray) { |
| 209 | // may be attempt wrapped Java array |
| 210 | Object tmp = ((NativeJavaArray)val).unwrap(); |
| 211 | Object[] res; |
| 212 | if (tmp.getClass() == Object[].class) { |
| 213 | Object[] array = (Object[]) tmp; |
| 214 | res = new Object[array.length]; |
| 215 | for (int index = 0; index < array.length; index++) { |
| 216 | res[index] = mapToId(array[index]); |
| 217 | } |
| 218 | } else { |
| 219 | // just return an empty array |
| 220 | res = Context.emptyArgs; |
| 221 | } |
| 222 | return res; |
| 223 | } else { |
| 224 | // some other return type, just return empty array |
| 225 | return Context.emptyArgs; |
| 226 | } |
| 227 | } else { |
| 228 | return getAdaptee().getIds(); |
| 229 | } |
| 230 | } |
| 231 | |
| 232 | public boolean hasInstance(Scriptable scriptable) { |
| 233 | if (scriptable instanceof JSAdapter) { |
| 234 | return true; |
| 235 | } else { |
| 236 | Scriptable proto = scriptable.getPrototype(); |
| 237 | while (proto != null) { |
| 238 | if (proto.equals(this)) return true; |
| 239 | proto = proto.getPrototype(); |
| 240 | } |
| 241 | return false; |
| 242 | } |
| 243 | } |
| 244 | |
| 245 | public Object getDefaultValue(Class hint) { |
| 246 | return getAdaptee().getDefaultValue(hint); |
| 247 | } |
| 248 | |
| 249 | public Object call(Context cx, Scriptable scope, Scriptable thisObj, |
| 250 | Object[] args) |
| 251 | throws RhinoException { |
| 252 | if (isPrototype) { |
| 253 | return construct(cx, scope, args); |
| 254 | } else { |
| 255 | Scriptable tmp = getAdaptee(); |
| 256 | if (tmp instanceof Function) { |
| 257 | return ((Function)tmp).call(cx, scope, tmp, args); |
| 258 | } else { |
| 259 | throw Context.reportRuntimeError("TypeError: not a function"); |
| 260 | } |
| 261 | } |
| 262 | } |
| 263 | |
| 264 | public Scriptable construct(Context cx, Scriptable scope, Object[] args) |
| 265 | throws RhinoException { |
| 266 | if (isPrototype) { |
| 267 | Scriptable topLevel = ScriptableObject.getTopLevelScope(scope); |
| 268 | JSAdapter newObj; |
| 269 | if (args.length > 0) { |
| 270 | newObj = new JSAdapter(Context.toObject(args[0], topLevel)); |
| 271 | } else { |
| 272 | throw Context.reportRuntimeError("JSAdapter requires adaptee"); |
| 273 | } |
| 274 | return newObj; |
| 275 | } else { |
| 276 | Scriptable tmp = getAdaptee(); |
| 277 | if (tmp instanceof Function) { |
| 278 | return ((Function)tmp).construct(cx, scope, args); |
| 279 | } else { |
| 280 | throw Context.reportRuntimeError("TypeError: not a constructor"); |
| 281 | } |
| 282 | } |
| 283 | } |
| 284 | |
| 285 | public Scriptable getAdaptee() { |
| 286 | return adaptee; |
| 287 | } |
| 288 | |
| 289 | public void setAdaptee(Scriptable adaptee) { |
| 290 | if (adaptee == null) { |
| 291 | throw new NullPointerException("adaptee can not be null"); |
| 292 | } |
| 293 | this.adaptee = adaptee; |
| 294 | } |
| 295 | |
| 296 | //-- internals only below this point |
| 297 | |
| 298 | // map a property id. Property id can only be an Integer or String |
| 299 | private Object mapToId(Object tmp) { |
| 300 | if (tmp instanceof Double) { |
| 301 | return new Integer(((Double)tmp).intValue()); |
| 302 | } else { |
| 303 | return Context.toString(tmp); |
| 304 | } |
| 305 | } |
| 306 | |
| 307 | private static Scriptable getFunctionPrototype(Scriptable scope) { |
| 308 | return ScriptableObject.getFunctionPrototype(scope); |
| 309 | } |
| 310 | |
| 311 | private Function getAdapteeFunction(String name) { |
| 312 | Object o = ScriptableObject.getProperty(getAdaptee(), name); |
| 313 | return (o instanceof Function)? (Function)o : null; |
| 314 | } |
| 315 | |
| 316 | private Object call(Function func, Object[] args) { |
| 317 | Context cx = Context.getCurrentContext(); |
| 318 | Scriptable thisObj = getAdaptee(); |
| 319 | Scriptable scope = func.getParentScope(); |
| 320 | try { |
| 321 | return func.call(cx, scope, thisObj, args); |
| 322 | } catch (RhinoException re) { |
| 323 | throw Context.reportRuntimeError(re.getMessage()); |
| 324 | } |
| 325 | } |
| 326 | |
| 327 | private Scriptable prototype; |
| 328 | private Scriptable parent; |
| 329 | private Scriptable adaptee; |
| 330 | private boolean isPrototype; |
| 331 | |
| 332 | // names of adaptee JavaScript functions |
| 333 | private static final String GET_PROP = "__get__"; |
| 334 | private static final String HAS_PROP = "__has__"; |
| 335 | private static final String PUT_PROP = "__put__"; |
| 336 | private static final String DEL_PROP = "__delete__"; |
| 337 | private static final String GET_PROPIDS = "__getIds__"; |
| 338 | } |