usage.md

FOSElasticaBundle Usage

Basic Searching with a Finder

The most useful searching method is to use a finder defined by the index configuration. A finder will return results that have been hydrated by the configured persistence backend, allowing you to use relationships of returned entities. For more information about configuration options for this kind of searching, please see the indexes documentation.

This example assumes you have defined an index user in your config.yml.

# config/services.yaml
services:
    # ...

    App\Controller\UserController:
        tags: ['controller.service_arguments']
        public: true
        arguments:
            - '@fos_elastica.finder.user'

namespace App\Controller;

use FOS\ElasticaBundle\Finder\PaginatedFinderInterface;

class UserController
{
    private $finder;

    public function __construct(PaginatedFinderInterface $finder)
    {
        $this->finder = $finder;
    }

    public function userAction()
    {
        // Option 1. Returns all users who have example.net in any of their mapped fields
        $results = $this->finder->find('example.net');

        // Option 2. Returns a set of hybrid results that contain all Elasticsearch results
        // and their transformed counterparts. Each result is an instance of a HybridResult
        $results = $this->finder->findHybrid('example.net');

        // Option 3a. Pagerfanta'd resultset
        /** var Pagerfanta\Pagerfanta */
        $userPaginator = $this->finder->findPaginated('bob');
        $countOfResults = $userPaginator->getNbResults();

        // Option 3b. KnpPaginator resultset
        $paginator = $this->get('knp_paginator');
        $results = $this->finder->createPaginatorAdapter('bob');
        $pagination = $paginator->paginate($results, $page, 10);

        // You can specify additional options as the fourth parameter of Knp Paginator
        // paginate method to nested_filter and nested_sort

        $options = [
            'sortNestedPath' => 'owner',
            'sortNestedFilter' => new Query\Term(['enabled' => ['value' => true]]),
        ];

        // sortNestedPath and sortNestedFilter also accepts a callable
        // which takes the current sort field to get the correct sort path/filter

        $pagination = $paginator->paginate($results, $page, 10, $options);
    }
}

When searching with a finder, parameters can be passed which influence the Elasticsearch query in general.

For example, the search_type parameter (see the Elasticsearch documentation) can be set as follows:

$results = $this->finder->findHybrid('example.net', null, ['search_type' => 'dfs_query_then_fetch']);

Aggregations

When searching with aggregations, they can be retrieved when using the paginated methods on the finder.

$query = new \Elastica\Query();
$agg = new \Elastica\Aggregation\Terms('tags');
$agg->setField('companyGroup');
$query->addAggregation($agg);

$companies = $this->finder->findPaginated($query);
$companies->setMaxPerPage($params['limit']);
$companies->setCurrentPage($params['page']);

$aggs = $companies->getAdapter()->getAggregations();

Searching the entire index

You can also define a finder that will work on the entire index. Adjust your index configuration as per below:

fos_elastica:
    indexes:
        app:
            finder: ~

You can now use the index wide finder service fos_elastica.finder.app:

/** var FOS\ElasticaBundle\Finder\MappedFinder */
$finder = $this->container->get('fos_elastica.finder.app');

// Returns a mixed array of any objects mapped
$results = $finder->find('bob');

Index Repositories

In the case where you need many different methods for different searching terms, it may be better to separate methods for each index into their own dedicated repository classes, just like Doctrine ORM's EntityRepository classes.

The manager class that handles repositories has a service key of fos_elastica.manager. The manager will default to handling ORM entities, and the configuration must be changed for MongoDB users.

fos_elastica:
    default_manager: mongodb

An example for using a repository:

# config/services.yaml
services:
    # ...

    App\Controller\UserController:
        tags: ['controller.service_arguments']
        public: true
        arguments:
            - '@fos_elastica.manager'

namespace App\Controller;

use FOS\ElasticaBundle\Manager\RepositoryManagerInterface;

class UserController extends Controller
{
    /** @var RepositoryManagerInterface */
    private $repositoryManager;

    public function __construct(RepositoryManagerInterface $repositoryManager)
    {
        $this->repositoryManager = $repositoryManager;
    }

    public function userAction()
    {
        $repository = $this->repositoryManager->getRepository('UserBundle:User');

        /** var array of App\UserBundle\Entity\User */
        $users = $repository->find('bob');
    }
}

For more information about customising repositories, see the cookbook entry Custom Repositories.

Using a custom query builder method for transforming results

When returning results from Elasticsearch to be transformed by the bundle, the default createQueryBuilder method on each objects Repository class will be called. In many circumstances this is not ideal and you'd prefer to use a different method to join in any entity relations that are required on the page that will be displaying the results.

fos_elastica:
    indexes:
        user:
            persistence:
                elastica_to_model_transformer:
                    query_builder_method: createSearchQueryBuilder

An example for using a custom query builder method:

class UserRepository extends EntityRepository
{
    /**
     * Used by Elastica to transform results to model
     * 
     * @param string $entityAlias
     * @return  Doctrine\ORM\QueryBuilder
     */
    public function createSearchQueryBuilder($entityAlias)
    {
        $qb = $this->createQueryBuilder($entityAlias);

        $qb->select($entityAlias, 'g')
            ->innerJoin($entityAlias.'.groups', 'g');

        return $qb;
    }
}

Advanced Searching Example

If you would like to perform more advanced queries, here is one example using the snowball stemming algorithm.

It searches for Article entities using title, tags, and categoryIds. Results must match at least one specified categoryIds, and should match the title or tags criteria. Additionally, we define a snowball analyzer to apply to queries against the title field.

Assuming an index is configured as follows:

fos_elastica:
    indexes:
        article:
            settings:
                index:
                    analysis:
                        analyzer:
                            my_analyzer:
                                type: snowball
                                language: English
            persistence:
                driver: orm
                model: Acme\DemoBundle\Entity\Article
                provider: ~
                finder: ~
            properties:
                title: { boost: 10, analyzer: my_analyzer }
                tags:
                categoryIds:

The following code will execute a search against the Elasticsearch server:

$finder = $this->container->get('fos_elastica.finder.app.article');
$boolQuery = new \Elastica\Query\BoolQuery();

$fieldQuery = new \Elastica\Query\MatchQuery();
$fieldQuery->setFieldQuery('title', 'I am a title string');
$fieldQuery->setFieldParam('title', 'analyzer', 'my_analyzer');
$boolQuery->addShould($fieldQuery);

$tagsQuery = new \Elastica\Query\Terms('tags', ['tag1', 'tag2']);
$boolQuery->addShould($tagsQuery);

$categoryQuery = new \Elastica\Query\Terms('categoryIds', ['1', '2', '3']);
$boolQuery->addMust($categoryQuery);

$data = $finder->find($boolQuery);

Note: While passing an array of queries like this

$boolQuery->addShould([$fieldQuery, $tagsQuery]);

works fine with Elasticsearch up to version 7.6, it will result in an error like

[bool] failed to parse field [should]

with version 7.7 and above.