I'm getting a weird error where in Internet Explorer 7, when I call Math.round on a float it gives me an "Invalid Argument" error. Consider the following:
var elementLeft = parseInt(element.style.left); // Here we're actually getting NaN
function Foo(x) {
this.x = x;
this.apply = function(element) {
element.style.left = Math.round(this.x) + 'px';
};
}
Foo(elementLeft);
In this case x is a non-negative number and element is just a DOM element in my page (a div, in fact).
Any ideas?
EDIT: The variable passed in as the x parameter is actually initialized earlier as parseInt(element.style.left). It appears that the first time I try to read element.style.left, IE is actually giving back NaN. I have updated the code to reflect this. Anyone know any workarounds for this?
It appears that the first time I try to read element.style.left, IE is actually giving back NaN.
The first time you read element.style.left, is there actually any left style set on the element? Remember element.style only reflects style properties set in the inline style="..." attribute and not those applied by stylesheets.
If you haven't set an inline style, style.left will give you the undefined object, which does indeed parseInt to NaN.
Is IE defaulting x to a bad value?
Scroll down to Item 10 on this page:
Everything was working fine in
Firefox, Google Chrome etal. But I was
having problems with IE (of all
flavours). No selection tool would be
presented and a javascript warning was
produced which told me about an
'Invalid argument' being submitted to
the Math.round function.
The cause was that when you first
click on the image to start your
selection, the scaleX and scaleY
variables in the javascript on the
page result in a value of Infinity.
Firefox and every other browser seems
to silently step over this and carry
on processing as normal. IE of course
did not.
The solution was to add the following
line after the initial scaleX and
scaleY variables are calculated. This
appears to have solved the problem
fully. if(scaleX == Infinity || scaleY
== Infinity) return false; I hope this helps someone else and saves them the
hour of hunting it cost me ;o)
I don't think it's Math.round() that's giving you the error. It's probably the CSS subsystem. Try an alert() on the value that you're getting.
Some frameworks such as jQuery have facilities to read the calculated position of elements -- without requiring you to have explicitly set CSS position properties on them. Try reading the position of your element through jQuery. It might work.
