abranhe/minifier.php

## minifier.php
<?php

/**
 * W3C Fix and HTML minifier
 * Nobody knows how this work, so don't touch it!!!
 *
 * https://wordpress.stackexchange.com/a/227896/129134
 * https://stackoverflow.com/a/41148695
 */

add_action('wp_loaded', 'outputBufferStart');
add_action('shutdown', 'outputBufferEnd');

function outputBufferStart()
{
    ob_start("minify");
}

function outputBufferEnd()
{
    ob_get_clean();
}

/**
 * Minify HTML output.
 */
function minify($buffer)
{
    if (!is_admin() && !(defined('DOING_AJAX') && DOING_AJAX)) {

        // Remove type from Javascript and CSS.
        $buffer = preg_replace("%[ ]type=[\'\"]text\/(javascript|css)[\'\"]%", '', $buffer);

        // Add alt attribute to images where not exists.
        $buffer = preg_replace('%(<img(?!.*?alt=([\'"]).*?\2)[^>]*?)(/?>)%', '$1 alt="" $3', $buffer);
        $buffer = preg_replace('%\s+alt="%', ' alt="', $buffer);

        // Clear <head> tag.
        $buffer = preg_replace_callback('/(?=<head(.*?)>)(.*?)(?<=<\/head>)/s', 'cleanHTML', $buffer);

        // Clear <body>.
        $buffer = preg_replace_callback('/(?=<body(.*?)>)(.*?)(?<=<\/body>)/s', 'cleanHTML', $buffer);

        // Clear <scripts>
        $buffer = preg_replace_callback('/(?=<script(.*?)>)(.*?)(?<=<\/script>)/s', 'cleanJavascript', $buffer);

        // Clear <styles>
        $buffer = preg_replace_callback('/(?=<style(.*?)>)(.*?)(?<=<\/style>)/s', 'cleanCSS', $buffer);

        // Clean between <head> and <body> tags.
        $buffer = preg_replace("%</head>([\s\t\n\r]+)<body%", '</head><body', $buffer);

        // Clean between body and <html> tags.
        $buffer = preg_replace("%</body>([\s\t\n\r]+)</html>%", '</body></html>', $buffer);

        // Clean between <html> and <head>
        $buffer = preg_replace("%<html(.*?)>([\s\t\n\r]+)<head%", '<html$1><head', $buffer);
    }

    return $buffer;
}

/**
 * Clean HTML.
 */
function cleanHTML($matches)
{
    return preg_replace([
        '/<!--(?!\s*(?:\[if [^\]]+]|<!|>))(?:(?!-->).)*-->/s',
        '/\>[^\S ]+/s',
        '/[^\S ]+\</s',
        '/\>\s+\</',
    ], ['', '>', '<', '><'], $matches[2]);
}

/**
 * Clean scripts.
 */
function cleanJavascript($matches)
{
    return preg_replace([
        '@\/\*(.*?)\*\/@s',
        '@((^|\t|\s|\r)\/{2,}.+?(\n|$))@s',
        '@(\}(\n|\s+)else(\n|\s+)\{)@s',
        '@((\)\{)|(\)(\n|\s+)\{))@s',
        '@(\}(\n+|\t+|\s+)else\sif(\s+|)\()@s',
        '@(if|for|while|switch|function)\(@s',
        '@\s+(\={1,3}|\:)\s+@s',
        '@\$\((.*?)\)@s',
        '@(if|while)\s\((.*?)\)\s\{@s',
        '@function\s\(\s+\)\s{@s',
        '@(\n{2,})@s',
        '@([\r\n\s\t]+)(,)@s',
        '@([\r\n\s\t]+)?([;,{}()]+)([\r\n\s\t]+)?@',
    ], [
        "\n",
        "\n",
        '}else{',
        '){',
        '}else if(',
        "$1(",
        " $1 ",
        '$' . "($1)",
        "$1 ($2) {",
        'function(){',
        "\n",
        ',',
        "$2",
    ], $matches[2]);
}

/**
 * Clean styles.
 */
function cleanCSS($matches)
{
    return preg_replace([
        '/([.#]?)([a-zA-Z0-9,_-]|\)|\])([\s|\t|\n|\r]+)?{([\s|\t|\n|\r]+)(.*?)([\s|\t|\n|\r]+)}([\s|\t|\n|\r]+)/s',
        '/([0-9a-zA-Z]+)([;,])([\s|\t|\n|\r]+)?/s',
        '@([\r\n\s\t]+)?([;:,{}()]+)([\r\n\s\t]+)?@',
    ], [
        '$1$2{$5} ',
        '$1$2',
        "$2",
    ], $matches[2]);
}
	<?php

	/**
	* W3C Fix and HTML minifier
	* Nobody knows how this work, so don't touch it!!!
	*
	* https://wordpress.stackexchange.com/a/227896/129134
	* https://stackoverflow.com/a/41148695
	*/

	add_action('wp_loaded', 'outputBufferStart');
	add_action('shutdown', 'outputBufferEnd');

	function outputBufferStart()
	{
	ob_start("minify");
	}

	function outputBufferEnd()
	{
	ob_get_clean();
	}

	/**
	* Minify HTML output.
	*/
	function minify($buffer)
	{
	if (!is_admin() && !(defined('DOING_AJAX') && DOING_AJAX)) {

	// Remove type from Javascript and CSS.
	$buffer = preg_replace("%[ ]type=[\'\"]text\/(javascript\|css)[\'\"]%", '', $buffer);

	// Add alt attribute to images where not exists.
	$buffer = preg_replace('%(<img(?!.?alt=([\'"]).?\2)[^>]*?)(/?>)%', '$1 alt="" $3', $buffer);
	$buffer = preg_replace('%\s+alt="%', ' alt="', $buffer);

	// Clear <head> tag.
	$buffer = preg_replace_callback('/(?=<head(.?)>)(.?)(?<=<\/head>)/s', 'cleanHTML', $buffer);

	// Clear <body>.
	$buffer = preg_replace_callback('/(?=<body(.?)>)(.?)(?<=<\/body>)/s', 'cleanHTML', $buffer);

	// Clear <scripts>
	$buffer = preg_replace_callback('/(?=<script(.?)>)(.?)(?<=<\/script>)/s', 'cleanJavascript', $buffer);

	// Clear <styles>
	$buffer = preg_replace_callback('/(?=<style(.?)>)(.?)(?<=<\/style>)/s', 'cleanCSS', $buffer);

	// Clean between <head> and <body> tags.
	$buffer = preg_replace("%</head>([\s\t\n\r]+)<body%", '</head><body', $buffer);

	// Clean between body and <html> tags.
	$buffer = preg_replace("%</body>([\s\t\n\r]+)</html>%", '</body></html>', $buffer);

	// Clean between <html> and <head>
	$buffer = preg_replace("%<html(.*?)>([\s\t\n\r]+)<head%", '<html$1><head', $buffer);
	}

	return $buffer;
	}

	/**
	* Clean HTML.
	*/
	function cleanHTML($matches)
	{
	return preg_replace([
	'/<!--(?!\s(?:\[if [^\]]+]\|<!\|>))(?:(?!-->).)-->/s',
	'/\>[^\S ]+/s',
	'/[^\S ]+\</s',
	'/\>\s+\</',
	], ['', '>', '<', '><'], $matches[2]);
	}

	/**
	* Clean scripts.
	*/
	function cleanJavascript($matches)
	{
	return preg_replace([
	'@\/\(.?)\*\/@s',
	'@((^\|\t\|\s\|\r)\/{2,}.+?(\n\|$))@s',
	'@(\}(\n\|\s+)else(\n\|\s+)\{)@s',
	'@((\)\{)\|(\)(\n\|\s+)\{))@s',
	'@(\}(\n+\|\t+\|\s+)else\sif(\s+\|)\()@s',
	'@(if\|for\|while\|switch\|function)\(@s',
	'@\s+(\={1,3}\|\:)\s+@s',
	'@\$\((.*?)\)@s',
	'@(if\|while)\s\((.*?)\)\s\{@s',
	'@function\s\(\s+\)\s{@s',
	'@(\n{2,})@s',
	'@([\r\n\s\t]+)(,)@s',
	'@([\r\n\s\t]+)?([;,{}()]+)([\r\n\s\t]+)?@',
	], [
	"\n",
	"\n",
	'}else{',
	'){',
	'}else if(',
	"$1(",
	" $1 ",
	'$' . "($1)",
	"$1 ($2) {",
	'function(){',
	"\n",
	',',
	"$2",
	], $matches[2]);
	}

	/**
	* Clean styles.
	*/
	function cleanCSS($matches)
	{
	return preg_replace([
	'/([.#]?)([a-zA-Z0-9,_-]\|\)\|\])([\s\|\t\|\n\|\r]+)?{([\s\|\t\|\n\|\r]+)(.*?)([\s\|\t\|\n\|\r]+)}([\s\|\t\|\n\|\r]+)/s',
	'/([0-9a-zA-Z]+)([;,])([\s\|\t\|\n\|\r]+)?/s',
	'@([\r\n\s\t]+)?([;:,{}()]+)([\r\n\s\t]+)?@',
	], [
	'$1$2{$5} ',
	'$1$2',
	"$2",
	], $matches[2]);
	}