Is IE 8 Support Totally broken?

tazz_ben

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Mar 10, 2010, 6:32:32 PM3/10/10

to google-excanvas

So I was doing a basic test to present as a potential solution to
client and I wanted to show just that an image could be rotated and
with excanvas it would work on IE. While this code works on other
platforms, on IE 8, the Microsoft developer tools throws an error when
I try to access "getContext". Here is the code:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html>
<head>

</head>
<body>
<canvas id="testimage" width="150" height="150"></canvas>
<script type="text/javascript">
var canvasimage = {};

canvasimage.canvas = function (canvasid){
var canvasid = canvasid || "testimage";
var canvas = document.getElementById(canvasid);
var ctx = canvas.getContext('2d');
return ctx;
}();

canvasimage.loadpng = function (){
var img = new Image();
img.onload = function(){
canvasimage.canvas.drawImage(img,0,0);
};
img.src = 'test.png';
return img;
}();

canvasimage.rotate = function(degree){
canvasimage.canvas.rotate(Number(degree) * Math.PI / 180);
};

canvasimage.rotate(15);
// canvasimage.rotate(-15);
</script>
</body>
</html>

Please tell me I'm missing something, without the getContext method,
I'm not sure how excanvas has much value.

Fabien

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Mar 12, 2010, 4:43:09 PM3/12/10

to google-excanvas

Yep, you are missing something : reading the docs ;)
http://code.google.com/p/explorercanvas/wiki/Instructions
And sometimes, the initElement needs to be called even when the canvas
tag already exists. There are also a few differences with the native
implementation.

Aseem Kishore

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Mar 12, 2010, 5:00:12 PM3/12/10

to google-...@googlegroups.com

I'm guessing this is because <canvas> elements in the HTML are automatically initialized -- but that's once the page loads ("document ready"), while your script is executing -- and using that <canvas> before the page has finished loading.

Aseem

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