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PHP Function to Minify HTML, CSS and JavaScript
<?php
/**
* ----------------------------------------------------------------------------------------
* Based on `https://github.com/mecha-cms/mecha-cms/blob/master/engine/plug/converter.php`
* ----------------------------------------------------------------------------------------
*/
// Helper function(s) ...
define('X', "\x1A"); // a placeholder character
$SS = '"(?:[^"\\\]++|\\\.)*+"|\'(?:[^\'\\\\]++|\\\.)*+\'';
$CC = '\/\*[\s\S]*?\*\/';
$CH = '<\!--[\s\S]*?-->';
function __minify_x($input) {
return str_replace(array("\n", "\t", ' '), array(X . '\n', X . '\t', X . '\s'), $input);
}
function __minify_v($input) {
return str_replace(array(X . '\n', X . '\t', X . '\s'), array("\n", "\t", ' '), $input);
}
/**
* =======================================================
* HTML MINIFIER
* =======================================================
* -- CODE: ----------------------------------------------
*
* echo minify_html(file_get_contents('test.html'));
*
* -------------------------------------------------------
*/
function _minify_html($input) {
return preg_replace_callback('#<\s*([^\/\s]+)\s*(?:>|(\s[^<>]+?)\s*>)#', function($m) {
if(isset($m[2])) {
// Minify inline CSS declaration(s)
if(stripos($m[2], ' style=') !== false) {
$m[2] = preg_replace_callback('#( style=)([\'"]?)(.*?)\2#i', function($m) {
return $m[1] . $m[2] . minify_css($m[3]) . $m[2];
}, $m[2]);
}
return '<' . $m[1] . preg_replace(
array(
// From `defer="defer"`, `defer='defer'`, `defer="true"`, `defer='true'`, `defer=""` and `defer=''` to `defer` [^1]
'#\s(checked|selected|async|autofocus|autoplay|controls|defer|disabled|hidden|ismap|loop|multiple|open|readonly|required|scoped)(?:=([\'"]?)(?:true|\1)?\2)#i',
// Remove extra white-space(s) between HTML attribute(s) [^2]
'#\s*([^\s=]+?)(=(?:\S+|([\'"]?).*?\3)|$)#',
// From `<img />` to `<img/>` [^3]
'#\s+\/$#'
),
array(
// [^1]
' $1',
// [^2]
' $1$2',
// [^3]
'/'
),
str_replace("\n", ' ', $m[2])) . '>';
}
return '<' . $m[1] . '>';
}, $input);
}
function minify_html($input) {
if( ! $input = trim($input)) return $input;
global $CH;
// Keep important white-space(s) after self-closing HTML tag(s)
$input = preg_replace('#(<(?:img|input)(?:\s[^<>]*?)?\s*\/?>)\s+#i', '$1' . X . '\s', $input);
// Create chunk(s) of HTML tag(s), ignored HTML group(s), HTML comment(s) and text
$input = preg_split('#(' . $CH . '|<pre(?:>|\s[^<>]*?>)[\s\S]*?<\/pre>|<code(?:>|\s[^<>]*?>)[\s\S]*?<\/code>|<script(?:>|\s[^<>]*?>)[\s\S]*?<\/script>|<style(?:>|\s[^<>]*?>)[\s\S]*?<\/style>|<textarea(?:>|\s[^<>]*?>)[\s\S]*?<\/textarea>|<[^<>]+?>)#i', $input, -1, PREG_SPLIT_NO_EMPTY | PREG_SPLIT_DELIM_CAPTURE);
$output = "";
foreach($input as $v) {
if($v !== ' ' && trim($v) === "") continue;
if($v[0] === '<' && substr($v, -1) === '>') {
if($v[1] === '!' && strpos($v, '<!--') === 0) { // HTML comment ...
// Remove if not detected as IE comment(s) ...
if(substr($v, -12) !== '<![endif]-->') continue;
$output .= $v;
} else {
$output .= __minify_x(_minify_html($v));
}
} else {
// Force line-break with `&#10;` or `&#xa;`
$v = str_replace(array('&#10;', '&#xA;', '&#xa;'), X . '\n', $v);
// Force white-space with `&#32;` or `&#x20;`
$v = str_replace(array('&#32;', '&#x20;'), X . '\s', $v);
// Replace multiple white-space(s) with a space
$output .= preg_replace('#\s+#', ' ', $v);
}
}
// Clean up ...
$output = preg_replace(
array(
// Remove two or more white-space(s) between tag [^1]
'#>([\n\r\t]\s*|\s{2,})<#',
// Remove white-space(s) before tag-close [^2]
'#\s+(<\/[^\s]+?>)#'
),
array(
// [^1]
'><',
// [^2]
'$1'
),
$output);
$output = __minify_v($output);
// Remove white-space(s) after ignored tag-open and before ignored tag-close (except `<textarea>`)
return preg_replace('#<(code|pre|script|style)(>|\s[^<>]*?>)\s*([\s\S]*?)\s*<\/\1>#i', '<$1$2$3</$1>', $output);
}
/**
* =======================================================
* CSS MINIFIER
* =======================================================
* -- CODE: ----------------------------------------------
*
* echo minify_css(file_get_contents('test.css'));
*
* -------------------------------------------------------
*/
function _minify_css($input) {
// Keep important white-space(s) in `calc()`
if(stripos($input, 'calc(') !== false) {
$input = preg_replace_callback('#\b(calc\()\s*(.*?)\s*\)#i', function($m) {
return $m[1] . preg_replace('#\s+#', X . '\s', $m[2]) . ')';
}, $input);
}
// Minify ...
return preg_replace(
array(
// Fix case for `#foo [bar="baz"]` and `#foo :first-child` [^1]
'#(?<![,\{\}])\s+(\[|:\w)#',
// Fix case for `[bar="baz"] .foo` and `@media (foo: bar) and (baz: qux)` [^2]
'#\]\s+#', '#\b\s+\(#', '#\)\s+\b#',
// Minify HEX color code ... [^3]
'#\#([\da-f])\1([\da-f])\2([\da-f])\3\b#i',
// Remove white-space(s) around punctuation(s) [^4]
'#\s*([~!@*\(\)+=\{\}\[\]:;,>\/])\s*#',
// Replace zero unit(s) with `0` [^5]
'#\b(?:0\.)?0([a-z]+\b|%)#i',
// Replace `0.6` with `.6` [^6]
'#\b0+\.(\d+)#',
// Replace `:0 0`, `:0 0 0` and `:0 0 0 0` with `:0` [^7]
'#:(0\s+){0,3}0(?=[!,;\)\}]|$)#',
// Replace `background(?:-position)?:(0|none)` with `background$1:0 0` [^8]
'#\b(background(?:-position)?):(0|none)\b#i',
// Replace `(border(?:-radius)?|outline):none` with `$1:0` [^9]
'#\b(border(?:-radius)?|outline):none\b#i',
// Remove empty selector(s) [^10]
'#(^|[\{\}])(?:[^\{\}]+)\{\}#',
// Remove the last semi-colon and replace multiple semi-colon(s) with a semi-colon [^11]
'#;+([;\}])#',
// Replace multiple white-space(s) with a space [^12]
'#\s+#'
),
array(
// [^1]
X . '\s$1',
// [^2]
']' . X . '\s', X . '\s(', ')' . X . '\s',
// [^3]
'#$1$2$3',
// [^4]
'$1',
// [^5]
'0',
// [^6]
'.$1',
// [^7]
':0',
// [^8]
'$1:0 0',
// [^9]
'$1:0',
// [^10]
'$1',
// [^11]
'$1',
// [^12]
' '
),
$input);
}
function minify_css($input) {
if( ! $input = trim($input)) return $input;
global $SS, $CC;
// Keep important white-space(s) between comment(s)
$input = preg_replace('#(' . $CC . ')\s+(' . $CC . ')#', '$1' . X . '\s$2', $input);
// Create chunk(s) of string(s), comment(s) and text
$input = preg_split('#(' . $SS . '|' . $CC . ')#', $input, -1, PREG_SPLIT_NO_EMPTY | PREG_SPLIT_DELIM_CAPTURE);
$output = "";
foreach($input as $v) {
if(trim($v) === "") continue;
if(
($v[0] === '"' && substr($v, -1) === '"') ||
($v[0] === "'" && substr($v, -1) === "'") ||
(strpos($v, '/*') === 0 && substr($v, -2) === '*/')
) {
// Remove if not detected as important comment ...
if($v[0] === '/' && strpos($v, '/*!') !== 0) continue;
$output .= $v; // String or comment ...
} else {
$output .= _minify_css($v);
}
}
// Remove quote(s) where possible ...
$output = preg_replace(
array(
// '#(' . $CC . ')|(?<!\bcontent\:|[\s\(])([\'"])([a-z_][-\w]*?)\2#i',
'#(' . $CC . ')|\b(url\()([\'"])([^\s]+?)\3(\))#i'
),
array(
// '$1$3',
'$1$2$4$5'
),
$output);
return __minify_v($output);
}
/**
* =======================================================
* JAVASCRIPT MINIFIER
* =======================================================
* -- CODE: ----------------------------------------------
*
* echo minify_js(file_get_contents('test.js'));
*
* -------------------------------------------------------
*/
function _minify_js($input) {
return preg_replace(
array(
// Remove inline comment(s) [^1]
'#\s*\/\/.*$#m',
// Remove white-space(s) around punctuation(s) [^2]
'#\s*([!%&*\(\)\-=+\[\]\{\}|;:,.<>?\/])\s*#',
// Remove the last semi-colon and comma [^3]
'#[;,]([\]\}])#',
// Replace `true` with `!0` and `false` with `!1` [^4]
'#\btrue\b#', '#\bfalse\b#', '#\breturn\s+#'
),
array(
// [^1]
"",
// [^2]
'$1',
// [^3]
'$1',
// [^4]
'!0', '!1', 'return '
),
$input);
}
function minify_js($input) {
if( ! $input = trim($input)) return $input;
// Create chunk(s) of string(s), comment(s), regex(es) and text
global $SS, $CC;
$input = preg_split('#(' . $SS . '|' . $CC . '|\/[^\n]+?\/(?=[.,;]|[gimuy]|$))#', $input, -1, PREG_SPLIT_NO_EMPTY | PREG_SPLIT_DELIM_CAPTURE);
$output = "";
foreach($input as $v) {
if(trim($v) === "") continue;
if(
($v[0] === '"' && substr($v, -1) === '"') ||
($v[0] === "'" && substr($v, -1) === "'") ||
($v[0] === '/' && substr($v, -1) === '/')
) {
// Remove if not detected as important comment ...
if(strpos($v, '//') === 0 || (strpos($v, '/*') === 0 && strpos($v, '/*!') !== 0 && strpos($v, '/*@cc_on') !== 0)) continue;
$output .= $v; // String, comment or regex ...
} else {
$output .= _minify_js($v);
}
}
return preg_replace(
array(
// Minify object attribute(s) except JSON attribute(s). From `{'foo':'bar'}` to `{foo:'bar'}` [^1]
'#(' . $CC . ')|([\{,])([\'])(\d+|[a-z_]\w*)\3(?=:)#i',
// From `foo['bar']` to `foo.bar` [^2]
'#([\w\)\]])\[([\'"])([a-z_]\w*)\2\]#i'
),
array(
// [^1]
'$1$2$4',
// [^2]
'$1.$3'
),
$output);
}
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