Generate a Copy of a Function

Posted on 2008-06-23
Last Modified: 2008-06-25
I'm looking to copy a function, override it, and use the copy where I overrided the function.

For example:
file: fns.js, function test(a, b){ return (a+b)};
file: index.html
var oldFn = test;

function test(a,b) {
  return oldFn(a+2, b-2);

index.html is including fns.js.

The error I'm seeing is "Too many recursive calls." Which is leading me to believe that the oldFn var is being replaced with the new declration of "test", so it's calling itself.

I've done a lot of searching and haven't found anything that could help. There's a lot of examples of object copying (which I've tried, with no luck), but nothing with function copying.

Thanks in advance
Question by:AWarrenM
  • 4
  • 2

Author Comment

ID: 21851556
increased point value.
LVL 42

Expert Comment

by:David S.
ID: 21852563
Which browser(s) did you get that error message in?

Author Comment

ID: 21856153
Firefox for right now. Didn't test it in IE.
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Author Comment

ID: 21862160
Bumping again..
LVL 42

Accepted Solution

David S. earned 300 total points
ID: 21862196
Ah. I should have tested with your exact code earlier.

Try using an anonymous function when you redefine it:
function test(a, b){ return (a+b)};
var oldFn = test;
test=function(a,b) {
  return oldFn(a+2, b-2);

Open in new window


Author Comment

ID: 21867768
Wow Krav.. I thought I tried that. But I looked back and noticed I had  test  = new function...

Silly silly.

Thank you.

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