PHP & determining client screen resolution

Lemming

Just wondering if anyone knows how to get PHP to read in a user's screen resolution

much the same as the following javascript will do:

function resolution()
{
yPoint = screen.height ;
xPoint = screen.width ;
}

Or ... how to get the values from that javascript into php session variables or some such??

jd

Originally posted by Lemming
Just wondering if anyone knows how to get PHP to read in a user's screen resolution

much the same as the following javascript will do:

function resolution()
{
yPoint = screen.height ;
xPoint = screen.width ;
}

Or ... how to get the values from that javascript into php session variables or some such??

This may help -just lifted it from one of theose hit tracking sites

<script language=javascript><!--
s="";sc="";screencolors="";var xy = navigator.appVersion;xz = xy.substring(0,3);function
write(){document.write("<a href='http://sitestatz.com/check.cgi?id=someuser' target='_top'>");
document.write("<img height='25' width='25' border='0' alt='SiteStatz - free statistic tracker'",
"src='http://sitestatz.com/statz.cgi?id=someuser&browser="+navigator.appName+"&version="+xz+"",
"&ref="+escape(document.referrer)+"&screen="+s.height+"x"+s.width+"&colors="+sc+"'></a>");}
//--></script><script language="javascript1.2"><!--
s=screen;xy!="Netscape"?sc=s.colorDepth:sc=s.pixelDepth;
//--></script><script language="javascript"><!--
write();//--></script><noscript><a href="http://sitestatz.com/check.cgi?id=someuser">
<img src="http://sitestatz.com/statz.cgi?id=someuser" border=0></a></noscript>

Enygma

You could set a dummy index page that gets those values in javascript and sets them in a form and submits it. It should be pretty quick so the user shouldn't really notice.

<form name="resolutionForm" action="setResolution.php" method="POST">
   <input type="hidden" name="width" />
   <input type="hidden" name="height" />
</form>

<script language="javascript">
// set form values and submit the form
// this isn't tested, you might need to change this but you get the idea
document.resolutionForm.width.value = screen.width;
document.resolutionForm.height.value = screen.height;
document.resolutionForm.submit();
</script>

In setResolution.php just set those values into the session. You could put a piece of code in the top of ever page to check whether they exist or not in the session and if they don't, redirect the above page. You could also pass a referring page so it could go back to the page they're looking for.

Hope this makes sense.

dahamsta

Hi Lemming,

Since no-one else has pointed it out, you can't do this in PHP, because PHP is server-side. So, as others have suggested, you need to tie in with a client-side language like JavaScript. Enygma's method is one example, although you don't actually need to use a form, you can just do it with a 'location' redirect:

<script language="JavaScript">
 <!--
  w = screen.width;
  h = screen.height;
  top.location = '?w=' + w '&h=' + h;
 // -->
</script>

This will send the user back to the same page, but this time with the width and height in the QUERY_STRING. You can check for the existance of these vars in the PHP script, and, for example, set them in a cookie, or start a session. Alternatively, you could set a cookie on the first load with JavaScript.

Also note that the dimensions you will get back will be the actual resolution, and won't cater for the chrome of the browser. (Or whether the window is normalised for that matter.)

adam