silverstripe-docsviewer/code/extensions/DocumentationSearchExtension.php

<?php

class DocumentationSearchExtension extends Extension
{
    /**
     * Return an array of folders and titles
     *
     * @return array
     */
    public function getSearchedEntities()
    {
        $entities = array();

        if (!empty($_REQUEST['Entities'])) {
            if (is_array($_REQUEST['Entities'])) {
                $entities = Convert::raw2att($_REQUEST['Entities']);
            } else {
                $entities = explode(',', Convert::raw2att($_REQUEST['Entities']));
                $entities = array_combine($entities, $entities);
            }
        }
        
        return $entities;
    }
    
    /**
     * Return an array of versions that we're allowed to return
     *
     * @return array
     */
    public function getSearchedVersions()
    {
        $versions = array();
        
        if (!empty($_REQUEST['Versions'])) {
            if (is_array($_REQUEST['Versions'])) {
                $versions = Convert::raw2att($_REQUEST['Versions']);
                $versions = array_combine($versions, $versions);
            } else {
                $version = Convert::raw2att($_REQUEST['Versions']);
                $versions[$version] = $version;
            }
        }

        return $versions;
    }
    
    /**
     * Return the current search query.
     *
     * @return HTMLText|null
     */
    public function getSearchQuery()
    {
        if (isset($_REQUEST['Search'])) {
            return DBField::create_field('HTMLText', $_REQUEST['Search']);
        } elseif (isset($_REQUEST['q'])) {
            return DBField::create_field('HTMLText', $_REQUEST['q']);
        }
    }

    /**
     * Past straight to results, display and encode the query.
     */
    public function getSearchResults()
    {
        $query = $this->getSearchQuery();

        $search = new DocumentationSearch();
        $search->setQuery($query);
        $search->setVersions($this->getSearchedVersions());
        $search->setModules($this->getSearchedEntities());
        $search->setOutputController($this->owner);
        
        return $search->renderResults();
    }
    
    /**
     * Returns an search form which allows people to express more complex rules
     * and options than the plain search form.
     *
     * @return Form
     */
    public function AdvancedSearchForm()
    {
        return new DocumentationAdvancedSearchForm($this->owner);
    }

    /**
     * @return bool
     */
    public function getAdvancedSearchEnabled()
    {
        return Config::inst()->get("DocumentationSearch", 'advanced_search_enabled');
    }
}