minify html
<?php
define('SAFE', 1);
define('EXTREME', 2);
define('EXTREME_SAVE_COMMENTS', 4);
define('EXTREME_SAVE_PRE', 3);
function minify($html, $level=2)
{
switch((int)$level)
{
case 0:
//Don't minify
break;
case 1: //Safe Minify
// Replace all whitespace characters between tags with a single space
$html = preg_replace("`>\s+<`", "> <", $html);
break;
case 2: //Extreme Minify
// Placeholder to save conditional comment hack, <pre> and <code> tags
$place_holders = array(
'<!-->' => '_!--_',
);
//Set placeholders
$html = strtr($html, $place_holders);
// Remove all normal comments - save conditionals
$html = preg_replace('/<!--[^(\[|(<!))](.*)-->/Uis', '', $html);
// Replace all whitespace characters with a single space
$html = preg_replace("`\s+`", " ", $html);
// Remove the spaces between adjacent html tags
$html = preg_replace("`> <`", "><", $html);
// Replace space between adjacent a tags for readability
$html = str_replace("</a><a", "</a> <a", $html);
// Restore placeholders
$html = strtr($html, array_flip($place_holders));
break;
case 3: //Extreme, save pre and code tags
// Placeholder to save conditional comment hack, <pre> and <code> tags
$place_holders = array(
'<!-->' => '_!--_',
'<pre>' => '_pre_',
'</pre>' => '_/pre_',
'<code>' => '_code_',
'</code>' => '_/code_'
);
//Set placeholders
$html = strtr($html, $place_holders);
// Remove all normal comments - save conditionals
$html = preg_replace('/<!--[^(\[|(<!))](.*)-->/Uis', '', $html);
// Replace all whitespace characters with a single space
$html = preg_replace(">`\s+`<", "> <", $html);
// Remove the spaces between adjacent html tags
$html = preg_replace("`> <`", "><", $html);
// Replace space between adjacent a tags for readability
$html = str_replace("</a><a", "</a> <a", $html);
// Restore placeholders
$html = strtr($html, array_flip($place_holders));
break;
case 4: //Extreme minify, save comments
// Replace all whitespace characters with a single space
$html = preg_replace("`\s+`", " ", $html);
// Remove spaces between adjacent html tags
$html = preg_replace("`> <`", "><", $html);
// Restore space between ajacent a tags
$html = str_replace("</a><a", "</a> <a", $html);
break;
}
//Normalize ampersands
$html = str_replace("&", "&", $html);
$html = str_replace("&", "&", $html);
//Replace common entities with more compatible versions
$replace = array(
' ' => ' ',
'©' => '©',
'â' => 'â',
'¢' => '¢',
'»' => '»',
'«' => '«'
);
$html = strtr($html, $replace);
//Return minified html
return $html;
}