Compress HTML output with CodeIgniter

What it does

removes useless whitespace from HTML generated by CodeIgniter
works perfectly with CodeIgniter caching

How

check hooks are enabled

system/application/config/config.php

$config['enable_hooks'] = TRUE;

declare a new hook

system/application/config/hooks.php

// compress output
$hook['display_override'][] = array(
	'class' => '',
	'function' => 'compress',
	'filename' => 'compress.php',
	'filepath' => 'hooks'
	);

add the hook

system/application/hooks/compress.php

<?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');
 
function compress()
{
	$CI =& get_instance();
	$buffer = $CI->output->get_output();
 
	 $search = array(
		'/\n/',			// replace end of line by a space
		'/\>[^\S ]+/s',		// strip whitespaces after tags, except space
		'/[^\S ]+\</s',		// strip whitespaces before tags, except space
	 	'/(\s)+/s'		// shorten multiple whitespace sequences
	  );
 
	 $replace = array(
		' ',
		'>',
	 	'<',
	 	'\\1'
	  );
 
	$buffer = preg_replace($search, $replace, $buffer);
 
	$CI->output->set_output($buffer);
	$CI->output->_display();
}
 
/* End of file compress.php */
/* Location: ./system/application/hools/compress.php */

Notes

“cleaning code” from Tobias Goldkamp (with a minor addition to replace ends of lines by spaces). If you have problems with inline Javascript, try the code from Fatih Bazman below (#2).
possible to use HTML Tidy instead:

$options = array(
	'clean' => true,
	'hide-comments' => true,
	'indent' => true
	);
 
$buffer = tidy_parse_string($buffer, $options, 'utf8');
tidy_clean_repair($buffer);
 
// warning: if you generate XML, HTML Tidy will break it (by adding some HTML: doctype, head, body..) if not configured properly

Feedback

i got the CIOrgasm with this function. this is what i looking for for this last year.thx

believeMeYouDontWannaKnow
August 18, 2009
#1

Hello Jerome,

Thanks for coding. But I have noticed that Javascript codes doesn't works in codes, if codes are in "//" signs. Therefore, I revised your codes (actually Tobias Goldkamp side) like as below:

function compress()
{
 $CI =& get_instance();
 $buffer = $CI->output->get_output();
 
 $search = array(
    '/\>[^\S ]+/s', 
    '/[^\S ]+\</s', 
     '/(\s)+/s', // shorten multiple whitespace sequences
  '#(?://)?<!\[CDATA\[(.*?)(?://)?\]\]>#s' //leave CDATA alone
  );
 $replace = array(
     '>',
     '<',
     '\\1',
  "//&lt;![CDATA[\n".'\1'."\n//]]>"
  );

 $buffer = preg_replace($search, $replace, $buffer);

 $CI->output->set_output($buffer);
 $CI->output->_display();
}

Regards

Fatih Bazman
September 18, 2009
#2

are there any benchmarks to show how effective this step is? or does this exist more for code obfuscation?

matt
November 5, 2009
#3

Matt, it's mainly to show how easy it is to alter CodeIgniter output. However, with HTMLTidy, it can be used to remove comments, make sure the HTML is always correct, etc

Jérôme Jaglale
February 1, 2010
#4

<?php
if ( ! defined('BASEPATH')) exit('No direct script access allowed');

function compress()
{
$CI =& get_instance();
$buffer = $CI->output->get_output();

$search = array(
'/\>[^\S ]+/s', //strip whitespaces after tags, except space
'/[^\S ]+\</s', //strip whitespaces before tags, except space
'/(\s)+/s', // shorten multiple whitespace sequences
'//' //strip HTML comments
);
$replace = array(
'>',
'<',
'\\1',
''
);
$buffer = preg_replace($search, $replace, $buffer);

$CI->output->set_output($buffer);
$CI->output->_display();
}
?>

;)

Igor Ferreira Cemim
February 9, 2010
#5

Thank you very much. It helped me a lot.

Luka
July 30, 2010
#6