[thelist] Cookies and images

Fri Feb 4 10:15:37 CST 2005

Joshua Olson wrote:

>Simon,
>
>Thank you for you complete example.  I owe you an apology because it looks
>like I wasn't 100% succinct.  Clearly, in your example, the cookie that is
>set by the image is available on subsequent page loads.  I can honestly say
>that I was sure that would work.  What I was looking to do was to read the
>cookie AFTER the image loaded in the page, but without a page refresh.  To
>test, I fired a function to check for cookies within the image's onload
>handler.
>
>  
>
In my live test example I *do*  have access to the cookie using 
*JavaScript* on initial page load but only after the page has completed 
loading. My onload event is on the body tag. It was PHP that required 
the refresh.

>Something like this:
>
><img src="whatever.php" onload="checkforcookies()" />   
>
><script>
>  function checkforcookies()
>  {
>    alert(document.cookie);
>  }
></script>
>  
>
I don't think that an image tag supports the onload event :-(

http://www.w3.org/TR/REC-html40/struct/objects.html
http://www.w3.org/TR/REC-html40/sgml/dtd.html#events

Move the onload event trigger to the <body> element and I bet it works.

>In case you are wondering, my goal is to pass some meta information (about
>1k worth) about the picture back to the browser for parsing and subsequent
>display.  The picture may be dynamically changed using javascript.  I was
>hoping to avoid spinning off a second call to the server to retrieve this
>information.
>  
>
Still not clear what you are trying to achieve or quite what you mean by 
"meta information" in this context?

Simon