pjs/js/rhino/examples/Control.java

/* -*- Mode: java; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 *
 * The contents of this file are subject to the Netscape Public
 * License Version 1.1 (the "License"); you may not use this file
 * except in compliance with the License. You may obtain a copy of
 * the License at http://www.mozilla.org/NPL/
 *
 * Software distributed under the License is distributed on an "AS
 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
 * implied. See the License for the specific language governing
 * rights and limitations under the License.
 *
 * The Original Code is Rhino code, released
 * May 6, 1998.
 *
 * The Initial Developer of the Original Code is Netscape
 * Communications Corporation.  Portions created by Netscape are
 * Copyright (C) 1997-1999 Netscape Communications Corporation. All
 * Rights Reserved.
 *
 * Contributor(s):
 *
 * Alternatively, the contents of this file may be used under the
 * terms of the GNU Public License (the "GPL"), in which case the
 * provisions of the GPL are applicable instead of those above.
 * If you wish to allow use of your version of this file only
 * under the terms of the GPL and not to allow others to use your
 * version of this file under the NPL, indicate your decision by
 * deleting the provisions above and replace them with the notice
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 * the provisions above, a recipient may use your version of this
 * file under either the NPL or the GPL.
 */

import org.mozilla.javascript.*;

/**
 * Example of controlling the JavaScript execution engine.
 *
 * We evaluate a script and then manipulate the result.
 *
 */
public class Control {

    /**
     * Main entry point.
     *
     * Process arguments as would a normal Java program. Also
     * create a new Context and associate it with the current thread.
     * Then set up the execution environment and begin to
     * execute scripts.
     */
    public static void main(String[] args)
    {
        Context cx = Context.enter();
        try {
            // Set version to JavaScript1.2 so that we get object-literal style
            // printing instead of "[object Object]"
            cx.setLanguageVersion(Context.VERSION_1_2);

            // Initialize the standard objects (Object, Function, etc.)
            // This must be done before scripts can be executed.
            Scriptable scope = cx.initStandardObjects();

            // Now we can evaluate a script. Let's create a new object
            // using the object literal notation.
            Object result = cx.evaluateString(scope, "obj = {a:1, b:['x','y']}",
                                              "MySource", 1, null);

            Scriptable obj = (Scriptable) scope.get("obj", scope);

            // Should print "obj == result" (Since the result of an assignment
            // expression is the value that was assigned)
            System.out.println("obj " + (obj == result ? "==" : "!=") +
                               " result");

            // Should print "obj.a == 1"
            System.out.println("obj.a == " + obj.get("a", obj));

            Scriptable b = (Scriptable) obj.get("b", obj);

            // Should print "obj.b[0] == x"
            System.out.println("obj.b[0] == " + b.get(0, b));

            // Should print "obj.b[1] == y"
            System.out.println("obj.b[1] == " + b.get(1, b));

            // Should print {a:1, b:["x", "y"]}
            Function fn = (Function) ScriptableObject.getProperty(obj, "toString");
            System.out.println(fn.call(cx, scope, obj, new Object[0]));
        } finally {
            Context.exit();
        }
    }

}