Cached Dynamic Modules Page 4

The parse_it function scans the string to see if any tag occurs, and if it does, break
down the tagname in $fun and its optional parameters into the associated array $arglist.

<?php
function parse_it ($str) {
    global $loaded;
    if (eregi ("<[Mm][Yy]-([A-Za-z0-9]*) ([^>]*)", $str, $regs)) {
        $tag = $regs[1];
        if (!$loaded[$tag]) {
            include "res/$tag/$tag.php";
            $loaded[$tag] = 1;
        }
        $fun = "handle_$tag";
        $list = explode (" ", strtolower ($regs[2]));
        $cache_file = "cache/$tag";
        for ($i = 0; $i < count ($list); $i++) {
            if ($argname = strtok ($list[$i], "=")) {
                $arglist[$argname] = strtok ("=");
                if ($argname != "cache") {
                    $cache_file .= "_" . $argname . "=" . $arglist[$argname];
                }
            }
        }
        $buf = "<!-- $tag start here //-->n";
        $buf .= $fun ($arglist);
        $buf .= "n<!-- $tag ends here //-->n";
        return $buf;
    } else {
        return $str;
    }
}
?>

This function calls the function $tag directly in the file included from res/$tag/$tag.php
and uses the output to return to the parse main loop.

As you notice, the variable $cache_file is also being built pointing to cache/$tag…
where … is a string combining all parameters to form a unique cache entry for this tag. To
actually use the cache, we must add some code between the end of the for loop and the creation of $buf:

<?php
$read_cache = 0;
$write_cache = 0;
if (!(isset ($arglist["cache"]) && ($arglist["cache"] < 10))) {
    $write_cache = 1;
    if (file_exists ($cache_file)) {
        if (!isset ($arglist["cache"])) {
            if ((filemtime ($cache_file) + $default_cache_time) > date ("U")) {
                $read_cache = 1;
                $write_cache = 0;
            }    
        } else {
            if ((filemtime ($cache_file) + $arglist["cache"]) > date ("U")) {
                $read_cache = 1;
                $write_cache = 0;
            }
        }
    }
}
?>