Question

I have a function written in coffeescript that used to work fine but now throws an ‘Invalid Pointer’ exception in ie8.

The Coffee Script

convertSVGforIE = ->

  if not $.support.svg or device.ff36
    imagesToConvert = $('img.SVG')
    imagesToConvert.each ->
      imageSrcMinus = this.src.substr 0, this.src.length - 3
      this.src = imageSrcMinus + 'png'

The Javascript

convertSVGforIE = function() {
    var imagesToConvert;
    if (!$.support.svg || device.ff36) {
      imagesToConvert = $('img.SVG');
      return imagesToConvert.each(function() {
        var imageSrcMinus;
        imageSrcMinus = this.src.substr(0, this.src.length - 3); //Invalid pointer
        return this.src = imageSrcMinus + 'png';
      });
    }
};

I can’t see anything wrong with my script. Please help me determine, what is ie8’s problem.

UPDATE:
I got this to work, but not in a good way

convertSVGforIE = ->

  if not $.support.svg or device.ff36
    $('img.SVG').each ->
      that = $(this)
      imageSrcMinus = that.attr('src').substr 0, that.attr('src').length - 3
      that.attr 'src', imageSrcMinus+'png'

The above script works, but why does $(this).attr(‘src’) work? while this.src does not? And why only in IE?

Answer 1

If you look at http://msdn.microsoft.com/en-us/library/ms534643(v=vs.85).aspx, it says that

1. You can only do elem.src from IE8 or later, and
2. Exactly how this works depends on whether you’re in IE8 Standards Mode or Compatibility Mode.

If you look at the comments on that page, there are other quirks as well..

Using jQuery is certainly the easiest fix here, with the pleasant side effect of IE6-7 compatibility, but you may also want to try adding

<meta http-equiv="X-UA-Compatible" content="IE=8" />

to the head of the page to force IE8 into Standards Mode.