materio-d8/web/modules/custom/materio_sapi/src/Controller/Base.php

<?php
// https://www.drupal.org/docs/8/modules/search-api/developer-documentation/executing-a-search-in-code

namespace Drupal\materio_sapi\Controller;

use Drupal\Core\Controller\ControllerBase;
use Symfony\Component\HttpFoundation\JsonResponse;
use Symfony\Component\HttpFoundation\Request;
use Drupal\Component\Utility\Tags;
use Drupal\Component\Utility\Unicode;
use Drupal\search_api\Entity\Index;

// https://drupal.stackexchange.com/questions/225008/programatically-use-search-api

/**
 * Defines a route controller for materio sapi search (regular and ajax).
 */
class Base extends ControllerBase {

  private $limit = 15;
  private $offset = 0;

  private function sapiQuery(){
    $this->index = Index::load('database');
    $this->query = $this->index->query();

    // Change the parse mode for the search.
    $parse_mode = \Drupal::service('plugin.manager.search_api.parse_mode')
      ->createInstance('direct');
    $parse_mode->setConjunction('OR');
    $this->query->setParseMode($parse_mode);

    // Set fulltext search keywords and fields.
    $this->query->keys($this->keys);
    // $this->query->setFulltextFields(['name']);

    // Set additional conditions.
    // $this->query->addCondition('status', 1)
    //   ->addCondition('author', 1, '<>');

    // Restrict the search to specific languages.
    // $this->query->setLanguages(['de', 'it']);

    // Do paging.
    $this->query->range($this->offset, $this->limit);

    // Add sorting.
    $this->query->sort('search_api_relevance', 'DESC');

    // Set one or more tags for the query.
    // @see hook_search_api_query_TAG_alter()
    // @see hook_search_api_results_TAG_alter()
    $this->query->addTag('materio_sapi_search');

    $this->results = $this->query->execute();

  }

  /**
   * get params from request
   */
  private function parseRequest(Request $request){
    // Get the typed string from the URL, if it exists.
    $this->keys = $request->query->get('keys');
    if($this->keys){
      $this->keys = Unicode::strtolower($this->keys);
      // $this->keys = Tags::explode($this->keys);
      \Drupal::logger('materio_sapi')->notice($this->keys);
    }
    $this->term = $request->query->get('term');
    $this->offset = $request->query->get('offset') ?? $this->offset;
    $this->limit = $request->query->get('limit') ?? $this->limit;
  }

  /**
   * Handler for ajax search.
   */
  public function getResults(Request $request) {
    $this->parseRequest($request);

    $resp = [
      'keys' => $this->keys,
      'term' => $this->term,
      'range' => array(
        'offset' => $this->offset,
        'limit' => $this->limit
      ),
    ];

    if ($this->keys) {
      $this->sapiQuery();

      $resp['count'] = $this->results->getResultCount();
      $resp['infos'] = t('The search found @count result(s) with keywords @keys.', array(
        "@count" => $resp['count'],
        "@keys" => $this->keys
      ));


      $resp['options'] = $this->query->getOptions();

      // $items = [];
      $uuids = [];
      foreach ($this->results as $result) {
        // $nid = $result->getField('nid')->getValues()[0];
        // $uuid = $result->getField('uuid')->getValues()[0];
        // $title = $result->getField('title')->getValues()[0]->getText();
        // $items[] = [
        //   'nid' => $nid,
        //   'uuid' => $uuid,
        //   'title' => $title,
        // ];
        $uuids[] = $result->getField('uuid')->getValues()[0];
      }
      // $resp['items'] = $items;
      $resp['uuids'] = $uuids;
    }

    return new JsonResponse($resp);
  }


  /**
   * Handler for regular page search.
   */
  function pageHandler(Request $request){
    // \Drupal::logger('materio_sapi')->notice(print_r($request, true));

    $this->parseRequest($request);

    $resp = [
      "#title" => 'Base'
    ];

    if ($this->keys) {
      $resp['#title'] = $this->keys;

      $this->sapiQuery();

      $node_view_builder = \Drupal::entityTypeManager()->getViewBuilder('node');

      $items = $this->results->getResultItems();
      $this->items = [];
      foreach ($items as $item) {
        // \Drupal::logger('materio_sapi')->notice(print_r($item, true));
        try {
          /** @var \Drupal\Core\Entity\EntityInterface $entity */
          $entity = $item->getOriginalObject()->getValue();
        }
        catch (SearchApiException $e) {
          continue;
        }
        if (!$entity) {
          continue;
        }
        // TODO: define dynamicly viewmode
        $this->items[] = $node_view_builder->view($entity, 'teaser');

      }

      $resp['items'] = $this->items;
    }else{
      $resp['#markup'] = "no keys to search for";
    }

    return $resp;
  }
}