Evaluating Functions For Transfer In Ie8

I need to transfer JavaScript Objects through JSON and transfer it's functions as well. I found a working version of getting the Strings of Functions and transfering them. Then i c

Solution 1:

For what it's worth, the problem is caused by JScript incorrectly interpreting this:

(function x() {})

as a FunctionDeclaration and not a FunctionExpression, so doing a statement-eval instead of an expression-eval. Similar to what happens with {} object-literals without the wrapping brackets. You could get around it by doing something to more explicitly push it into parsing an expression, eg:

eval('['+myFunctionTransferString+'][0]');

But seriously don't. Never rely on the string representation of a function, it is not standardised and there are many browser differences.

You couldn't usefully preserve a function even if function decomposition were reliable, since there is much more to a function than the textual representation of its source. The closures it includes cannot be represented, and closures are ever-more common in real-world JavaScript.

I'm afraid there is no cheap way to serialise/re-instantiate JavaScript objects in general. The JSON subset is the reliable subset, the rest you'll have to code your own ad hoc serialisation formats for.

Solution 2:

Functions are not part of the JSON specification. Remember the JSON specification is a subset of JavaScript's syntax.

So your 'hacked' solution is actually the more correct one.

Solution 3:

Heres some hacked solutions:

var fn = function() { alert("some text"); }

var fnFromString = new Function("return " + fn.toString()); // functionanonymous() { returnfunction() { ... } }
fnFromString = fnFromString(); // function() { alert("some text"); }

and if you executing script immediately:

eval("(" + fn.toString() + ")()"); // fn executed.