Minify HTML wordpress

wp-minify.php

class HTML_Compression {
	protected $compress_css = true;
	protected $compress_js = true;
	protected $info_comment = true;
	protected $remove_comments = true;
	protected $html;
	
    public function __construct($html) {
    	if (!empty($html)) {
    		$this->parseHTML($html);
    	}
    }
    	
    public function __toString() {
    	return $this->html;
    }
    	
    protected function bottomComment($raw, $compressed) {
    	$raw = strlen($raw);
    	$compressed = strlen($compressed);
    	$savings = ($raw-$compressed) / $raw * 100;
    	$savings = round($savings, 2);
    	return;
    }
    	
    protected function minifyHTML($html) {
    	$pattern = '/<(?<script>script).*?<\/script\s*>|<(?<style>style).*?<\/style\s*>|<!(?<comment>--).*?-->|<(?<tag>[\/\w.:-]*)(?:".*?"|\'.*?\'|[^\'">]+)*>|(?<text>((<[^!\/\w.:-])?[^<]*)+)|/si';
    	preg_match_all($pattern, $html, $matches, PREG_SET_ORDER);
    	$overriding = false;
    	$raw_tag = false;
    	$html = '';
    	
    	foreach($matches as $token) {
    		$tag = (isset($token['tag'])) ? strtolower($token['tag']) : null;
    		$content = $token[0];
    		
    		if (is_null($tag)) {
    			if ( !empty($token['script']) ) {
    				$strip = $this->compress_js;
    			} else if (!empty($token['style'])) {
    				$strip = $this->compress_css;
    			} else if ($content == '<!--wp-html-compression no compression-->') {
    				$overriding = !$overriding; 
    				continue;
    			} else if ($this->remove_comments) {
    				if(!$overriding && $raw_tag != 'textarea') {
    					$content = preg_replace('/<!--(?!\s*(?:\[if [^\]]+]|<!|>))(?:(?!-->).)*-->/s', '', $content);
                    }
                }
            } else {
                if ($tag == 'pre' || $tag == 'textarea') {
                    $raw_tag = $tag;
                } else if ($tag == '/pre' || $tag == '/textarea') {
                    $raw_tag = false;
                } else {
                    if ($raw_tag || $overriding) {
                        $strip = false;
                    } else {
                        $strip = true; 
                        $content = preg_replace('/(\s+)(\w++(?<!\baction|\balt|\bcontent|\bsrc)="")/', '$1', $content); 
                        $content = str_replace(' />', '/>', $content);
                    }
                }
            }
            if($strip) {
                $content = $this->removeWhiteSpace($content);
            }
            $html .= $content;
        }
    
        return $html;
    }
    
    public function parseHTML($html) {
        $this->html = $this->minifyHTML($html);
        if($this->info_comment) {
            $this->html .= "\n" . $this->bottomComment($html, $this->html);
        }
    }
    
    protected function removeWhiteSpace($str) {
        $str = str_replace("\t", ' ', $str);
        $str = str_replace("\n",  '', $str);
        $str = str_replace("\r",  '', $str);
    
        while (stristr($str, '  ')) {
            $str = str_replace('  ', ' ', $str);
        }
        return $str;
    }
}

function wp_html_compression_finish($html) {
    return new HTML_Compression($html);
}

function wp_html_compression_start() {
    ob_start('wp_html_compression_finish');
}

add_action('get_header', 'wp_html_compression_start');