smarty templates newbie - looping through images with function

[quasiman]

I'm new to Smarty (this is v.2), so my question may seem dumb...or impossible.

First, I have a link directory that I want to enhance a bit, to include a thumbnail from the 'Shrink the web' thumbnail service (shrinktheweb.com). 

So I wrote up a function that downloads/caches the thumbnail:

function get_stw_image($url,$accesskey,$secretkey,$size = "sm")
{
 $agents[] = "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0)";
 $agents[] = "Opera/9.63 (Windows NT 6.0; U; ru) Presto/2.1.1";
 $agents[] = "Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.9.0.5) Gecko/2008120122 Firefox/3.0.5";
 $agents[] = "Mozilla/5.0 (X11; U; Linux i686 (x86_64); en-US; rv:1.8.1.18) Gecko/20081203 Firefox/2.0.0.18";
 $agents[] = "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.16) Gecko/20080702 Firefox/2.0.0.16";
 $agents[] = "Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10_5_6; en-us) AppleWebKit/525.27.1 (KHTML, like Gecko) Version/3.2.1 Safari/525.27.1";
 $local = $url;
$fullpath = "/images/".$local;
$expire_time    = 5; //days before expired 
    // Read file creation time
    $FileCreationTime = filectime($fullpath);
    // Calculate file age in seconds
    $FileAge = time() - $FileCreationTime;
if(!file_exists($fullpath) || $FileAge > ($expire_time * 1440)) {
	$image 	= "http://images.shrinktheweb.com/xino.php?stwembed=1";
	$image	.= "&stwaccesskeyid=".$accesskey;
	$image	.="&stwu=".$secretkey;
	$size 	.= "&stwsize=".$size;
	$image	.= "&stwurl=".$url;
	$ch = curl_init($image);
	$fp = fopen($fullpath,'w');
$options = array( 
	CURLOPT_RETURNTRANSFER => true, // return web page
	CURLOPT_HEADER => false, // don't return headers
	CURLOPT_FOLLOWLOCATION => false, // follow redirects 
	CURLOPT_AUTOREFERER => true, // set referer on redirect 
	CURLOPT_CONNECTTIMEOUT => 5, // timeout on connect 
	CURLOPT_TIMEOUT => 5, // timeout on response 
	CURLOPT_FILE => $fp, //file handler
	CURLOPT_MAXREDIRS => 0, // stop after 10 redirects 
	CURLOPT_USERAGENT => $agents[rand(0,(count($agents)-1))] //random browser agents...probably not necessary
	);
	curl_setopt_array( $ch, $options ); 
	curl_exec($ch);
}
return $fullpath;
}

No big deal, the function works fine on its own.  The problem now is that I can't figure out how to get it working in the template.

The template assignment is just :

$template->assign('links',$links);

And then the html page loops through each from the database:

<!--{section name=link loop=$links}-->
...
<!--{$links[link].linkurl|escape:'htmlall'}-->
...
<!--{/section}-->

 

So...how is this supposed to work?  How does my function know from the template which url is which?  Can I write an assignment that would loop through at the same time?

$template->assign('shrinktheweb',get_stw_image($linkurl,"MYACCESSKEY","MYSECRETKEY","sm"));

 

Maybe my function needs to be changed to somehow reference the template?

 

Any advise (or even direction to a similar scenario) would be greatly appreciated!

[quasiman]

I've partially figured this out, but still have an issue.

 

template file:

<!--{section name=link loop=$latest_links}-->
<!--{assign var='linksurls' value=`$latest_links[link].linkurl`}-->
<img src="<!--{$shrinktheweb|escape:'htmlall'}-->" />

 

index.php file:

$template->display($templatefile);
$linksurl = $template->get_template_vars('linksurls');
$template->assign('shrinktheweb',get_stw_image($linkurl,"MYACCESSKEY","MYSECRETKEY","sm"));

 

While my image is downloaded correctly, this doesn't allow me use the 'shrinktheweb' template assignment because it's after the template execution. 

My image just comes out as <img src="" />