yf_text_highlight class

    public function _regex_html_tag($html = '')
    {
        if (empty($html)) {
            return false;
        }
        // Too many embedded code/quote/html/sql tags can crash Opera and Moz
        if (preg_match("/\[(quote|code|html|sql)\].+?\[(quote|code|html|sql)\].+?\[(quote|code|html|sql)\].+?\[(quote|code|html|sql)\].+?\[(quote|code|html|sql)\]/i", $html)) {
            return $html;
        }
        // Take a stab at removing most of the common
        // smilie characters.
        $html = preg_replace('#:#', ':', $html);
        $html = preg_replace("#\[#", '[', $html);
        $html = preg_replace("#\]#", ']', $html);
        $html = preg_replace("#\)#", ')', $html);
        $html = preg_replace("#\(#", '(', $html);

        $html = preg_replace('/^<br>/', '', $html);
        $html = preg_replace('#^<br />#', '', $html);
        $html = preg_replace("/^\s+/", '', $html);

        $html = preg_replace('#<([^&<>]+)>#', "<<span style='color:blue'>\\1</span>>", $html); // Matches <tag>
        $html = preg_replace('#<([^&<>]+)=#', "<<span style='color:blue'>\\1</span>=", $html); // Matches <tag
        $html = preg_replace('#</([^&]+)>#', "</<span style='color:blue'>\\1</span>>", $html); // Matches </tag>
        $html = preg_replace("!=("|')(.+?)?("|')(\s|>)!", "=\\1<span style='color:orange'>\\2</span>\\3\\4", $html); // Matches ='this'
        $html = preg_replace('!<!--(.+?)-->!', "<!<span style='color:red'>--\\1--</span>>", $html);

        $wrap = $this->_wrap_style('html');

        return $wrap['START'] . $html . $wrap['END'];
    }

    public function _regex_sql_tag($sql = '')
    {
        if (empty($sql)) {
            return false;
        }
        // Too many embedded code/quote/html/sql tags can crash Opera and Moz
        if (preg_match("/\[(quote|code|html|sql)\].+?\[(quote|code|html|sql)\].+?\[(quote|code|html|sql)\].+?\[(quote|code|html|sql)\].+?\[(quote|code|html|sql)\].+?\[(quote|code|html|sql)\].+?\[(quote|code|html|sql)\].+?\[(quote|code|html|sql)\].+?\[(quote|code|html|sql)\]/i", $sql)) {
            return $sql;
        }
        // Knock off any preceeding newlines (which have
        // since been converted into <br>)
        $sql = preg_replace('/^<br>/', '', $sql);
        $sql = preg_replace('#^<br />#', '', $sql);
        $sql = preg_replace("/^\s+/", '', $sql);
        // Make certain regex work..
        if ( ! preg_match("/\s+$/", $sql)) {
            $sql = $sql . ' ';
        }

        $sql = preg_replace("#(=|\+|\-|>|<|~|==|\!=|LIKE|NOT LIKE|REGEXP)#i", "<span style='color:orange'>\\1</span>", $sql);
        $sql = preg_replace("#(MAX|AVG|SUM|COUNT|MIN)\(#i", "<span style='color:blue'>\\1</span>(", $sql);
        $sql = preg_replace('!("|'|')(.+?)("|'|')!i', "<span style='color:red'>\\1\\2\\3</span>", $sql);
        $sql = preg_replace("#\s{1,}(AND|OR)\s{1,}#i", " <span style='color:blue'>\\1</span> ", $sql);
        $sql = preg_replace("#(LEFT|JOIN|WHERE|MODIFY|CHANGE|AS|DISTINCT|IN|ASC|DESC|ORDER BY)\s{1,}#i", "<span style='color:green'>\\1</span> ", $sql);
        $sql = preg_replace("#LIMIT\s*(\d+)\s*,\s*(\d+)#i", "<span style='color:green'>LIMIT</span> <span style='color:orange'>\\1, \\2</span>", $sql);
        $sql = preg_replace("#(FROM|INTO)\s{1,}(\S+?)\s{1,}#i", "<span style='color:green'>\\1</span> <span style='color:orange'>\\2</span> ", $sql);
        $sql = preg_replace('#(SELECT|INSERT|UPDATE|DELETE|ALTER TABLE|DROP)#i', "<span style='color:blue;font-weight:bold'>\\1</span>", $sql);

        $html = $this->_wrap_style('sql');

        return $html['START'] . $sql . $html['END'];
    }

    public function _wrap_style($type = 'quote', $extra = '')
    {
        $used = [
           'quote' => [
                'title' => 'QUOTE',
                'css_top' => 'quotetop',
                'css_main' => 'quotemain',
            ],
           'code' => [
                'title' => 'CODE',
                'css_top' => 'codetop',
                'css_main' => 'codemain',
            ],
           'sql' => [
                'title' => 'SQL',
                'css_top' => 'sqltop',
                'css_main' => 'sqlmain',
            ],
           'html' => [
                'title' => 'HTML',
                'css_top' => 'htmltop',
                'css_main' => 'htmlmain',
            ],
        ];
        return [
            'START' => "<div class='" . $used[$type]['css_top'] . "'>" . $used[$type]['title'] . $extra . "</div><div class='" . $used[$type]['css_main'] . "'>",
            'END' => '</div>',
        ];
    }