Adding this code to your Drupal site can improve two sections of a YSlow report, "Make fewer HTTP requests" and "Minify JS". This function minifies and aggregates your javascript into a single file. It requires the Google code library jsmin-php (http://code.google.com/p/jsmin-php/).
Stick this function in your template.php file in your theme directory:
<?php
function minify_scripts($scripts) {
// define paths
$jsMinFileName = 'jsmin_minified.js';
$jsMinAbsolutePathDir = getcwd() . '/' . file_directory_path();
$jsMinAbsolutePath = $jsMinAbsolutePathDir . '/' . $jsMinFileName;
$jsMinRelativePath = base_path() . file_create_path($jsMinFileName);
// check to see if file is writable
if (
(!file_exists($jsMinAbsolutePath) && !is_writable($jsMinAbsolutePathDir))
||
(file_exists($jsMinAbsolutePath) && !is_writable($jsMinAbsolutePath))
) {
return $scripts;
}
// include js minify library
require_once('jsmin-1.1.1.php');
// split $scripts on new line
$exploded = explode("\n", trim($scripts));
$minifiedJS = "";
foreach ($exploded as $k => $v) {
// ensure this line is javascript
if (!(substr($v,0,7)=='<script' && substr($v,-9)=='</script>')) continue;
// convert <script> to xml
$xml = simplexml_load_string($v);
if ($xml['type']=='text/javascript' && strlen($xml['src'])) {
// define path to old file
$oldFile = getcwd() . $xml['src'];
// minify javascript
$minifiedJS .= JSMin::minify(file_get_contents($oldFile));
// unset exploded array entry
unset($exploded[$k]);
}
}
// check to see if javascript has not been minified
if (strlen($minifiedJS)==0) return $scripts;
// write file
file_put_contents($jsMinAbsolutePath, $minifiedJS);
// re-index array
sort($exploded);
// add entry
$exploded[] = "<script type='text/javascript' src='$jsMinRelativePath'></script>";
return implode("\n", $exploded);
}
?>In your page.tpl.php theme file, replace this line...
<?php
print $scripts
?>with
<?php
print minify_scripts($scripts);
?>You can also improve your score in the "Put JS at the bottom" section by ensuring this line of code resides at the bottom of your page.tpl.php file. I insert it just before this line:
<?php
print $closure;
?>
