Hashtag to link in humhub

part_of_RichText.php

    public static function convertHashtags($text)
    {
        return preg_replace_callback(
            '/#(?!039)([\w]+)/',  // all "word" characters, all digits, and underscore
            // brackets around the string AFTER the hashtag
            function ($hit) {
                // $matches[0] is the complete match (including the hashtag)
                // $matches[1] is the match for the subpattern enclosed in brackets
                return '[' . $hit[0] . '](' . 'http://localhost:8080/index.php?r=' . Html::encode('search/search/index') .
                    '&' . Html::encode('SearchForm[keyword]') . '=' . strtolower($hit[1]) . ')';
            }, $text);
    }

    public function run()
    {
        $this->originalText = $this->text;

        if ($this->encode) {
            $this->text = Html::encode($this->text);
        }


        if (!$this->minimal && !$this->edit) {
            $this->translateOmbed();

            // mark emails
            $this->text = preg_replace_callback('/[_a-zA-Z0-9-]+(\.[_a-zA-Z0-9-]+)*@[a-zA-Z0-9-]+(\.[a-zA-Z0-9-]+)*(\.[a-zA-Z]{2,3})/', function ($match) {
                return Html::mailto($match[0]);
            }, $this->text);
        }

        $this->text = self::convertHashtags($this->text);
        // get user and space details from guids
....