Fix for issue with Fluent search in SilverStripe 4 (thanks @hubertusanton)

fluentsearchfix.yml

---
Name: fluentsearchfix
---
SilverStripe\Core\Injector\Injector:
  SilverStripe\CMS\Search\SearchForm:
    class: Hamaka\Extensions\SearchFormFluentFixExt

SearchFormFluentFixExt.php

<?php
    
    namespace Hamaka\Extensions;
    
    use SilverStripe\CMS\Model\SiteTree;
    use SilverStripe\CMS\Search\SearchForm;
    use SilverStripe\ORM\ArrayList;
    use SilverStripe\ORM\DB;
    use SilverStripe\ORM\SS_List;
    use TractorCow\Fluent\State\FluentState;
    
    class SearchFormFluentFixExt extends SearchForm
    {
        
        /**
         * Return dataObjectSet of the results using current request to get info from form.
         * Wraps around {@link searchEngine()}.
         *
         * @return SS_List
         */
        public function getResults()
        {
            
            // Get request data from request handler
            $request = $this->getRequestHandler()->getRequest();
            
            $keywords = $request->requestVar('Search');
            
            $andProcessor = function ($matches) {
                return ' +' . $matches[2] . ' +' . $matches[4] . ' ';
            };
            $notProcessor = function ($matches) {
                return ' -' . $matches[3];
            };
            
            $keywords = preg_replace_callback('/()("[^()"]+")( and )("[^"()]+")()/i', $andProcessor, $keywords);
            $keywords = preg_replace_callback('/(^| )([^() ]+)( and )([^ ()]+)( |$)/i', $andProcessor, $keywords);
            $keywords = preg_replace_callback('/(^| )(not )("[^"()]+")/i', $notProcessor, $keywords);
            $keywords = preg_replace_callback('/(^| )(not )([^() ]+)( |$)/i', $notProcessor, $keywords);
            
            $keywords = $this->addStarsToKeywords($keywords);
                        
            // $results = DB::get_conn()->searchEngine($this->classesToSearch, $keywords, $start, $pageLength, "\"Relevance\" DESC", "", $booleanSearch);
            // replace with hard query (todo: pagination)
               
            $keywords = DB::get_conn()->escapeString($keywords);
            $htmlEntityKeywords = htmlentities($keywords, ENT_NOQUOTES, 'UTF-8');            
            
            $current_locale           = FluentState::singleton()->getLocale();
            $sitetree_table_localised = 'SiteTree_Localised_' . $current_locale;
            $sitetreetables           = 'SiteTree_Live.Title, SiteTree_Live.MenuTitle, SiteTree_Live.Content, SiteTree_Live.MetaDescription';
            
            $customResults = DB::query('SELECT DISTINCT SiteTree_Live.ID, SiteTree_Live.Title,
            MATCH ('.$sitetreetables.') AGAINST (\'' . str_replace(array('*', '+', '-'), '', $keywords) . '\') AS Relevance
            FROM SiteTree_Live
            LEFT JOIN SiteTree_Localised AS ' . $sitetree_table_localised . '
            ON SiteTree_Live.ID = ' . $sitetree_table_localised . '.RecordID AND ' . $sitetree_table_localised . '.Locale = \'' . $current_locale . '\' AND ((' . $sitetree_table_localised . '.ID IS NOT NULL))
            WHERE (
                MATCH ('.$sitetreetables.') AGAINST (\'' . $keywords . '\' IN BOOLEAN MODE)
                + MATCH ('.$sitetreetables.') AGAINST (\'' . $htmlEntityKeywords . '\' IN BOOLEAN MODE)
                AND SiteTree_Live.ShowInSearch <> 0
              )
             ORDER BY Relevance DESC
            LIMIT 20;');
                       
            $results = new ArrayList();
                       
            foreach ($customResults as $record) {
                $st = SiteTree::get_by_id($record['ID']);
                if ( ! empty($st) && $st->canView()) {
                    $results->push($st);
                }
            }
            
            return $results;
        }
        
    }

Thanks for this... However, when testing this with SS4.7.1 and fluent 5.0.0, my searchbar has a few odd characters. (screenshot). Is there a way to fix this?

Hmm... that's odd.
Seems not quite related to the fix mentioned above.

Maybe paste the code building this search-form, so more context is given on your specific problem. Or maybe try the https://forum.silverstripe.org/, more people can look at it there...

It's the default that comes with silverstripe. Namely: SilverStripe\CMS\Search\SearchForm.php

can i add dataobjects to the search too?