Use isNaN for IE opacity

[lrbabe]

function attr of core.js (the second one) use a strange test to detect NaN :

parseInt( value ) + "" == "NaN" ?

If appropriate, replace it with :

isNaN(parseInt(value))?

See proposed patch.

[lrbabe]

patch to replace the test with isNaN()

[flesler]

I wanted to do the same change some weeks ago. But for some reason the results were different.

[lrbabe]

By the way, if we are just testing if the value is a number, shouldn't we use value.constructor == Number ?

[lrbabe]

oops oops oops, never mind my last comment.

[lrbabe]

... actually you can mind it.

[flesler]

No, because it's a string. So value.constructor == String.

[flesler]

Right. The change could probably fit. I don't see much gain but might make it in. Will check this asap, it requires a lot of testing.

[dmethvin]

Here's the current line in 1.4.2:

var opacity = parseInt( value, 10 ) + "" === "NaN" ? "" : "alpha(opacity=" + value * 100 + ")";

parseInt() only looks for valid leading digits that can be followed by non-digits, but isNaN() requires the entire string to be a valid number. Opacity should be a number from 0.0 to 1.0 (not an integer). Also the Microsoft docs say the opacity should be an integer from 0 to 100.

​http://msdn.microsoft.com/en-us/library/ms532910%28v=VS.85%29.aspx

So it seems like the correct line would be this:

var opacity = isNaN(value) ? "" : "alpha(opacity=" + Math.round(value * 100) + ")";

[dmethvin]

Implemented in the rewrite of csshooks in 1.4.3.