class SearchPluginBase

abstract class SearchPluginBase extends PluginBase implements ContainerFactoryPluginInterface, SearchInterface, RefinableCacheableDependencyInterface {
    use RefinableCacheableDependencyTrait;
    
    /**
     * The keywords to use in a search.
     *
     * @var string
     */
    protected $keywords;
    
    /**
     * Array of parameters from the query string from the request.
     *
     * @var array
     */
    protected $searchParameters;
    
    /**
     * Array of attributes - usually from the request object.
     *
     * @var array
     */
    protected $searchAttributes;
    
    /**
     * {@inheritdoc}
     */
    public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
        return new static($configuration, $plugin_id, $plugin_definition);
    }
    
    /**
     * {@inheritdoc}
     */
    public function setSearch($keywords, array $parameters, array $attributes) {
        $this->keywords = (string) $keywords;
        $this->searchParameters = $parameters;
        $this->searchAttributes = $attributes;
        return $this;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getKeywords() {
        return $this->keywords;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getParameters() {
        return $this->searchParameters;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getAttributes() {
        return $this->searchAttributes;
    }
    
    /**
     * {@inheritdoc}
     */
    public function isSearchExecutable() {
        // Default implementation suitable for plugins that only use keywords.
        return !empty($this->keywords);
    }
    
    /**
     * {@inheritdoc}
     */
    public function getType() {
        return NULL;
    }
    
    /**
     * {@inheritdoc}
     */
    public function buildResults() {
        $results = $this->execute();
        $built = [];
        foreach ($results as $result) {
            $built[] = [
                '#theme' => 'search_result',
                '#result' => $result,
                '#plugin_id' => $this->getPluginId(),
            ];
        }
        return $built;
    }
    
    /**
     * {@inheritdoc}
     */
    public function searchFormAlter(array &$form, FormStateInterface $form_state) {
        // Empty default implementation.
    }
    
    /**
     * {@inheritdoc}
     */
    public function suggestedTitle() {
        // If the user entered a search string, truncate it and append it to the
        // title.
        if (!empty($this->keywords)) {
            return $this->t('Search for @keywords', [
                '@keywords' => Unicode::truncate($this->keywords, 60, TRUE, TRUE),
            ]);
        }
        // Use the default 'Search' title.
        return $this->t('Search');
    }
    
    /**
     * {@inheritdoc}
     */
    public function buildSearchUrlQuery(FormStateInterface $form_state) {
        // Grab the keywords entered in the form and put them as 'keys' in the GET.
        $keys = trim($form_state->getValue('keys'));
        $query = [
            'keys' => $keys,
        ];
        return $query;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getHelp() {
        // This default search help is appropriate for plugins like NodeSearch
        // that use the SearchQuery class.
        $help = [
            'list' => [
                '#theme' => 'item_list',
                '#items' => [
                    $this->t('Search looks for exact, case-insensitive keywords; keywords shorter than a minimum length are ignored.'),
                    $this->t('Use upper-case OR to get more results. Example: cat OR dog (content contains either "cat" or "dog").'),
                    $this->t('You can use upper-case AND to require all words, but this is the same as the default behavior. Example: cat AND dog (same as cat dog, content must contain both "cat" and "dog").'),
                    $this->t('Use quotes to search for a phrase. Example: "the cat eats mice".'),
                    $this->t('You can precede keywords by - to exclude them; you must still have at least one "positive" keyword. Example: cat -dog (content must contain cat and cannot contain dog).'),
                ],
            ],
        ];
        return $help;
    }
    
    /**
     * {@inheritdoc}
     */
    public function usesAdminTheme() {
        return $this->pluginDefinition['use_admin_theme'];
    }

}