sundar@1524: /*
sundar@1524:  * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
sundar@1524:  *
sundar@1524:  * Redistribution and use in source and binary forms, with or without
sundar@1524:  * modification, are permitted provided that the following conditions
sundar@1524:  * are met:
sundar@1524:  *
sundar@1524:  *   - Redistributions of source code must retain the above copyright
sundar@1524:  *     notice, this list of conditions and the following disclaimer.
sundar@1524:  *
sundar@1524:  *   - Redistributions in binary form must reproduce the above copyright
sundar@1524:  *     notice, this list of conditions and the following disclaimer in the
sundar@1524:  *     documentation and/or other materials provided with the distribution.
sundar@1524:  *
sundar@1524:  *   - Neither the name of Oracle nor the names of its
sundar@1524:  *     contributors may be used to endorse or promote products derived
sundar@1524:  *     from this software without specific prior written permission.
sundar@1524:  *
sundar@1524:  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
sundar@1524:  * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
sundar@1524:  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
sundar@1524:  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
sundar@1524:  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
sundar@1524:  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
sundar@1524:  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
sundar@1524:  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
sundar@1524:  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
sundar@1524:  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
sundar@1524:  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
sundar@1524:  */
sundar@1524: 
sundar@1524: // how to pass arbitrary "this" object for eval'ed script?
sundar@1524: 
sundar@1524: var obj = { foo: 44 };
sundar@1524: 
sundar@1524: // the following won't work. eval.apply is indirect eval call
sundar@1524: // and so 'this' will be global object always! So, this
sundar@1524: // line will print 'undefined'
sundar@1524: eval.apply(obj, [ " print(this.foo)" ]);
sundar@1524: 
sundar@1524: obj.myEval = eval;
sundar@1524: 
sundar@1524: // still won't work - still indirect 'eval' call!
sundar@1524: // still undefined is printed!
sundar@1524: obj.myEval("print(this.foo)");
sundar@1524: 
sundar@1524: function func(code) {
sundar@1524:     eval(code);
sundar@1524: }
sundar@1524: 
sundar@1524: // eval called inside func and so get's func's "this" as it's "this"!
sundar@1524: // So, 44 is printed
sundar@1524: 
sundar@1524: func.apply(obj, [ "print(this.foo)" ]);