user agents... .png or .gif?

[DaveLinger]

So basically I'm designing a new site, and the problem of transparent PNGs has arisen. Basically I just need some way to tell whether or not the browser that's looking at the page is capable of transparency in PNGs. In one of my past projects, I just made a LIST of compatible user agents, and made an IF statement, the problem with that being I have to update the list anytime the slightest update is released. Is there an easier way to make it work like "if you can, display this transparent PNG. Otherwise, show this gif."?

[Barand]

I'm only guessing here and haven't tried it, but can you use the return value from
[code]<?php
$tran_color = imagecolortransparent ($image);  // note no color specfied
?>
[/code]

to see if there is a transparent color for the image?

EDIT guess not, that wouldn't check browser, just the image.

[DaveLinger]

yeah... =/

Is there no database that's constantly updated and I could just like include it in my page and it could return .gif if no or .png if yes? Then I could just make it like...

[code]
<img src="images/test
<?php
$agent = $_USER_AGENT; //or whatever that variable is
include('http://www.somesite.com/somepage.php?agent=$agent');
?>
" />
[/code]

[Barand]

The only thing  that comes to mind is

www.php.net/get_browser

Towards the end of that page there's a link get latest settings from

http://www.garykeith.com/browsers/downloads.asp

but whether there is the particular setting that you would need in there, I don't know

[DaveLinger]

so wait... using get browser... could I just make it say like... if it's any version of firefox, use PNG. Any version of IE EXCEPT 7 use GIF?

[DaveLinger]

here's what I got to work; after downloading the appropriate .ini file and editing php.ini...

[code]
<?php
$ua = get_browser ();
if ( ( $ua->browser == "IE" ) && ( $ua->version < 7 ) ) {
echo ".gif";
}else{
echo ".png";
}
?>
[/code]

Basically any browser EXCEPT IE 6 and below gets the .png :D