Javascript onload event to resize image help
Question
This might be a simple one for you guys, im learning Javascript and have hit a problem. I am trying to have the script resize a particular image on the page when onload is called like so:
<script type="text/javascript">
function resizeSampleImage()
{
document.getElementById("sampleImage").style.height = (document.body.clientWidth) * 0.2;
}
</script>
...
<body onload = "resizeSampleImage();" >
...
<a href="http://www.buildingpeople.uk.com" target="_blank"> <img id="sampleImage" src="Images/BP snip.jpg" alt="BuildingPeople.uk.com" /> </a>
apologies, forgot to mention that is doesn't work! after loading the page in multiple browsers the image stays it native size and the error consoles say they fail to parsing value for height. Declaration dropped.
I have tried lots of different ways but cannot seem to get it to work.
4 answers
solution1
0 2010-12-18 15:20:48
(document.body.clientWidth) * 0.2 will give you an integer. The CSS height property accepts a length .
Add some units.
solution2
0 2010-12-18 15:30:24
There is a live example at http://jsbin.com/uyihe4
You can see the zoom effect when loading. I have only changed the
document.getElementById("sampleImage").style.height
to
document.getElementById("sampleImage").height
solution3
0 2011-03-08 13:22:40
Well, your problem is that the images may not be ready when you apply the styles to them.
Use this function instead (note it takes a DOM object):
var imgLoader = function(domImg) {
var imgObj = new Image();
imgObj.onload = function()
{
// apply styles
domImg.style.height = "100px";
}
imgObj.src = domImg.src;
}
solution4
-1 ACCPTED 2010-12-18 15:31:45
Though I haven't figure out the problem. But the following code snippet works for me (Tested in Chrome 8.0 and IE9.0Beta).
<html>
<head>
<title>test</title>
<script type="text/javascript">
function resizeSampleImage()
{
document.getElementById("sampleImage").style.height = (document.body.clientWidth) * 0.5;
}
</script>
</head>
<body onload="resizeSampleImage();">
<img id="sampleImage" src="http://news.mydrivers.com/Img/20101217/S03405153.jpg">
</body>
</html>
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