How to Gzip components?

Hi, I too had the same issue and solved it with JSmart.
It's a great tool, but has to be tweaked a little to fix our (mine?) needs.

To have it working, your server MUST be running mod_rewrite. There are some host that disabled mod_rewrite also. In that case, you're out of luck. Sorry.

You have to change the .htaccess file to redirect every single *.js or *.css request to the JSmart script. Add the following:

<IfModule mod_rewrite.c>
  RewriteEngine on

  #JSmart Condition
  RewriteRule ^(.*\.((js)|(css)))$ /jsmart/load.php?file=$1
</IfModule>

Notice that (probably) you already have everything in place but the RewriteRule. The jsmart directory is where you are uploading JSmart's load.php file.

Next, I found that minification/optimization on JSmart is very buggy, so I removed it. Use YUI Compressor, Packer or your tool of choice.

Because my server is running php inside CGI, the php getallheaders() function isn't available.
I substituted it with an equivalent php loop (see code).

I also added an Expire header to 60 days in the future (just to satisfy YSlow).

I'm posting the stripped down version of load.php I'm using.

/jsmart/load.php file:

<?php
/* JSmart v1.0 Final Release
 * Copyright (c) 2006 by Ali Farhadi.
 * Released under the terms of the GNU Public License.
 * See the GPL for details.
 *
 * Email: ali@farhadi.ir
 * Website: http://farhadi.ir/
 */
/*
 * ACA: Edited to disable minification and support PHP as CGI
 */

//Encoding of your js and css files. (utf-8 or iso-8859-1) 
define('JSMART_CHARSET', 'utf-8');

function header_exit($status) {
	header("HTTP/1.0 $status");
	exit();
}

function header_nocache() {
	// already expired
	header("Expires: Mon, 26 Jul 1997 05:00:00 GMT");
	// always modified
	header("Last-Modified: " . gmdate("D, d M Y H:i:s") . " GMT");
	// HTTP/1.1
	header("Cache-Control: no-store, no-cache, must-revalidate");
	header("Cache-Control: post-check=0, pre-check=0", false);
	header("Cache-Control: max-age=0", false);
	// HTTP/1.0
	header("Pragma: no-cache");
	//generate a unique Etag each time
	header('Etag: '.time());
}

function debug_exit($msg){
	//Show error messages if any error occurs (true or false)
	define('JSMART_DEBUG_ENABLED', true);
	if (!JSMART_DEBUG_ENABLED) {
		header_exit('404 Not Found');
	}
	header_nocache();
	header('Content-Type: text/html; charset='.JSMART_CHARSET);
	header("Content-Encoding: none");
	echo "//<script>\n";
	echo "alert('JSmart Error: ".($msg)."');\n";
	echo "//</script>\n";
	exit();
}

$current_path = addslashes(realpath(getcwd()));

$file = @$_GET['file'] or debug_exit('missing file parameter');
if (!preg_match('/\.((js)|(css))$/i', $file, $file_type)) debug_exit($file." is not a javascript or css file.");
$file_type = strtolower($file_type[1]);

$file = constant('JSMART_'.strtoupper($file_type).'_DIR') . $file;

if (!file_exists($file)) debug_exit($file." not found.\\n(the path is relative to $current_path)");

$mtime = filemtime($file);

if ($mtime < filemtime('load.php')) $mtime = filemtime('load.php');
$mtimestr = gmdate("D, d M Y H:i:s", $mtime) . " GMT";

// ACA: getallheaders not supported via CGI
//$headers = getallheaders();

// ACA: inlined function for getallheaders
foreach($_SERVER as $name => $value)
    if(substr($name, 0, 5) == 'HTTP_')
        $headers[str_replace(' ', '-', ucwords(strtolower(str_replace('_', ' ', substr($name, 5)))))] = $value;

header('Content-Type: '.($file_type=='js'?'application/x-javascript':'text/css').'; charset='.JSMART_CHARSET);

if (isset($headers['If-Modified-Since']) && $headers['If-Modified-Since'] == $mtimestr) 
	header_exit('304 Not Modified');

// ACA: add expires header
$offset = 1296000; // 60 * 24 * 60 * 60 seconds = 60 days
header("Expires: " . gmdate("D, d M Y H:i:s", time() + $offset) . " GMT");

header("Last-Modified: " . $mtimestr);
header("Cache-Control: must-revalidate", false);

$gzip_supported = 
	(isset($headers['Accept-Encoding']) &&
	array_search('gzip', array_map('trim', explode(',' , $headers['Accept-Encoding']))) !== false &&
	function_exists('gzencode'));

$cached_file = 'cache/'.md5($file).'.'.$file_type;

if ($gzip_supported) {
	header("Content-Encoding: gzip");
	$cached_file .= '.gz';
}

if (file_exists($cached_file) && $mtime < filemtime($cached_file)) {
	@readfile($cached_file) or debug_exit("Cannot read file ($cached_file)\\n(the path is relative to $current_path)");
} else {
	$file_contents = @file_get_contents($file) or debug_exit("Cannot read file ($file)\\n(the path is relative to $current_path)");
	
	if ($gzip_supported) $file_contents = @gzencode($file_contents, 8) or debug_exit("Gzipping failed");
	
	$handle = @fopen($cached_file, 'w') or debug_exit("Cache dir is not writable or doesn't exist (cache/)\\n(the path is relative to $current_path)");
	fwrite($handle, $file_contents);
	fclose($handle);

	echo $file_contents;
}
?>

Note: I have no relation to the original author of JSmart. I just modified his source and have no rights on it, but the project got discontinued 2 years ago, so there shouldn't be problem.

Comments marked as "// ACA" are mine. Put this into jsmart directory on your site root and have fun! You don't need the original config.php (I included what was there into load.php). On my host (Register.it), it works like a charm.

You just have to put load.php in jsmart dir and create a cache dir inside it (/jsmart/cache/). Give them proper access rights (check write permissions).

Bye!

SmartOptimizer is working well for me. Very easy to install... my YSlow score jumped 12 points.

I ran Yslow and am now trying to figure out how to effectively gzip items

I ran Yslow and am now trying to figure out how to effectively gzip items

Mod_deflate in apache2 is pretty much the same as mod_gzip in apache1.3, and mod_deflate is included with the apache2 source package. Both modules allow compressing of the apache server on the fly

http://railsgeek.com/2008/12/16/apache2-httpd-improving-performance-mod_...