1 /*

     2  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. 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.  Oracle designates this

     8  * particular file as subject to the "Classpath" exception as provided

     9  * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    22  * or visit www.oracle.com if you need additional information or have any

    23  * questions.

    24  */

    25 

    26 package com.sun.script.javascript;

    27 

    28 import sun.org.mozilla.javascript.internal.*;

    29 import javax.script.*;

    30 

    31 /**

    32  * This class serves as top level scope for Rhino. This class adds

    33  * 3 top level functions (bindings, scope, sync) and two constructors

    34  * (JSAdapter, JavaAdapter).

    35  *

    36  * @author A. Sundararajan

    37  * @since 1.6

    38  */

    39 public final class RhinoTopLevel extends ImporterTopLevel {

    40     RhinoTopLevel(Context cx, RhinoScriptEngine engine) {

    41         super(cx);

    42         this.engine = engine;

    43 

    44 

    45         // initialize JSAdapter lazily. Reduces footprint & startup time.

    46         new LazilyLoadedCtor(this, "JSAdapter",

    47                 "com.sun.script.javascript.JSAdapter",

    48                 false);

    49 

    50         /*

    51          * initialize JavaAdapter. We can't lazy initialize this because

    52          * lazy initializer attempts to define a new property. But, JavaAdapter

    53          * is an exisiting property that we overwrite.

    54          */

    55         JavaAdapter.init(cx, this, false);

    56 

    57         // add top level functions

    58         String names[] = { "bindings", "scope", "sync"  };

    59         defineFunctionProperties(names, RhinoTopLevel.class,

    60                 ScriptableObject.DONTENUM);

    61     }

    62 

    63     /**

    64      * The bindings function takes a JavaScript scope object

    65      * of type ExternalScriptable and returns the underlying Bindings

    66      * instance.

    67      *

    68      *    var page = scope(pageBindings);

    69      *    with (page) {

    70      *       // code that uses page scope

    71      *    }

    72      *    var b = bindings(page);

    73      *    // operate on bindings here.

    74      */

    75     public static Object bindings(Context cx, Scriptable thisObj, Object[] args,

    76             Function funObj) {

    77         if (args.length == 1) {

    78             Object arg = args[0];

    79             if (arg instanceof Wrapper) {

    80                 arg = ((Wrapper)arg).unwrap();

    81             }

    82             if (arg instanceof ExternalScriptable) {

    83                 ScriptContext ctx = ((ExternalScriptable)arg).getContext();

    84                 Bindings bind = ctx.getBindings(ScriptContext.ENGINE_SCOPE);

    85                 return Context.javaToJS(bind,

    86                            ScriptableObject.getTopLevelScope(thisObj));

    87             }

    88         }

    89         return cx.getUndefinedValue();

    90     }

    91 

    92     /**

    93      * The scope function creates a new JavaScript scope object

    94      * with given Bindings object as backing store. This can be used

    95      * to create a script scope based on arbitrary Bindings instance.

    96      * For example, in webapp scenario, a 'page' level Bindings instance

    97      * may be wrapped as a scope and code can be run in JavaScripe 'with'

    98      * statement:

    99      *

   100      *    var page = scope(pageBindings);

   101      *    with (page) {

   102      *       // code that uses page scope

   103      *    }

   104      */

   105     public static Object scope(Context cx, Scriptable thisObj, Object[] args,

   106             Function funObj) {

   107         if (args.length == 1) {

   108             Object arg = args[0];

   109             if (arg instanceof Wrapper) {

   110                 arg = ((Wrapper)arg).unwrap();

   111             }

   112             if (arg instanceof Bindings) {

   113                 ScriptContext ctx = new SimpleScriptContext();

   114                 ctx.setBindings((Bindings)arg, ScriptContext.ENGINE_SCOPE);

   115                 Scriptable res = new ExternalScriptable(ctx);

   116                 res.setPrototype(ScriptableObject.getObjectPrototype(thisObj));

   117                 res.setParentScope(ScriptableObject.getTopLevelScope(thisObj));

   118                 return res;

   119             }

   120         }

   121         return cx.getUndefinedValue();

   122     }

   123 

   124     /**

   125      * The sync function creates a synchronized function (in the sense

   126      * of a Java synchronized method) from an existing function. The

   127      * new function synchronizes on the <code>this</code> object of

   128      * its invocation.

   129      * js> var o = { f : sync(function(x) {

   130      *       print("entry");

   131      *       Packages.java.lang.Thread.sleep(x*1000);

   132      *       print("exit");

   133      *     })};

   134      * js> thread(function() {o.f(5);});

   135      * entry

   136      * js> thread(function() {o.f(5);});

   137      * js>

   138      * exit

   139      * entry

   140      * exit

   141      */

   142     public static Object sync(Context cx, Scriptable thisObj, Object[] args,

   143             Function funObj) {

   144         if (args.length == 1 && args[0] instanceof Function) {

   145             return new Synchronizer((Function)args[0]);

   146         } else {

   147             throw Context.reportRuntimeError("wrong argument(s) for sync");

   148         }

   149     }

   150 

   151     RhinoScriptEngine getScriptEngine() {

   152         return engine;

   153     }

   154 

   155     private RhinoScriptEngine engine;

   156 }