1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/samples/this_for_eval.js Fri Sep 04 17:17:44 2015 +0530
1.3 @@ -0,0 +1,54 @@
1.4 +/*
1.5 + * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
1.6 + *
1.7 + * Redistribution and use in source and binary forms, with or without
1.8 + * modification, are permitted provided that the following conditions
1.9 + * are met:
1.10 + *
1.11 + * - Redistributions of source code must retain the above copyright
1.12 + * notice, this list of conditions and the following disclaimer.
1.13 + *
1.14 + * - Redistributions in binary form must reproduce the above copyright
1.15 + * notice, this list of conditions and the following disclaimer in the
1.16 + * documentation and/or other materials provided with the distribution.
1.17 + *
1.18 + * - Neither the name of Oracle nor the names of its
1.19 + * contributors may be used to endorse or promote products derived
1.20 + * from this software without specific prior written permission.
1.21 + *
1.22 + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
1.23 + * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
1.24 + * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
1.25 + * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
1.26 + * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
1.27 + * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
1.28 + * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
1.29 + * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
1.30 + * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
1.31 + * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
1.32 + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.33 + */
1.34 +
1.35 +// how to pass arbitrary "this" object for eval'ed script?
1.36 +
1.37 +var obj = { foo: 44 };
1.38 +
1.39 +// the following won't work. eval.apply is indirect eval call
1.40 +// and so 'this' will be global object always! So, this
1.41 +// line will print 'undefined'
1.42 +eval.apply(obj, [ " print(this.foo)" ]);
1.43 +
1.44 +obj.myEval = eval;
1.45 +
1.46 +// still won't work - still indirect 'eval' call!
1.47 +// still undefined is printed!
1.48 +obj.myEval("print(this.foo)");
1.49 +
1.50 +function func(code) {
1.51 + eval(code);
1.52 +}
1.53 +
1.54 +// eval called inside func and so get's func's "this" as it's "this"!
1.55 +// So, 44 is printed
1.56 +
1.57 +func.apply(obj, [ "print(this.foo)" ]);
