To multiple records

This is the official documentation of the forestadmin/laravel-forestadmin v2+ and forestadmin/symfony-forestadmin PHP agents.

Relationships that point to multiple records are displayed in the frontend in the "Related Data" and "Explorer" Tab.

Explorer Tab

One-to-Many relations

In a one-to-many relationship, one record from a Collection is attached to multiple records of another Collection.

Think about countries and towns: a country has multiple towns, and each town belongs to a country.

use ForestAdmin\AgentPHP\DatasourceCustomizer\CollectionCustomizer;
use ForestAdmin\SymfonyForestAdmin\Service\ForestAgent;

// Link 'Country' to 'Town'
$forestAgent->customizeCollection(
    'Country',
    function (CollectionCustomizer $builder) {
        $builder->addOneToManyRelation(
            name: 'myTowns',
            foreignCollection: 'Town',
            originKey: 'country_id',
            originKeyTarget: 'id' // Optional (uses `Country` primary key by default)
        );
    }
);

Many-to-Many relations

In a many-to-many relation, 3 Collections are used instead of 2 to build the relation.

This allows multiple records from one Collection to be attached to multiple records from another Collection.

For instance, on a movie recommendation website, each user can rate many movies, and each movie can be rated by many users. The 3 Collections that are used are users (the "origin" Collection), ratings (the "through" Collection), and movies (the "foreign" Collection).

use ForestAdmin\AgentPHP\DatasourceCustomizer\CollectionCustomizer;
use ForestAdmin\SymfonyForestAdmin\Service\ForestAgent;

// Create one side of the relation ...
$forestAgent->customizeCollection(
    'User',
    function (CollectionCustomizer $builder) {
        $builder->addManyToManyRelation(
            name: 'ratedMovies',
            foreignCollection: 'Movie',
            throughCollection: 'Rating'
            originKey: 'user_id',
            originKeyTarget: 'id', // Optional (uses primary key of User by default)
            foreignKey: 'movie_id',
            foreignKeyTarget: 'id' // Optional (uses primary key of Movie by default)
        );
    }
)
    // ... and the other one.
    ->customizeCollection(
        'Movie',
        function (CollectionCustomizer $builder) {
            // ⚠️ Not 'OneToOne'
            $builder->addManyToOneRelation(
                name: 'whoRatedThisMovie',
                foreignCollection: 'User',
                throughCollection: 'Rating'
                originKey: 'movie_id',
                originKeyTarget: 'id', // Optional (uses primary key of Movie by default)
                foreignKey: 'user_id',
                foreignKeyTarget: 'id' // Optional (uses primary key of User by default)
            );
        }
    );

External relations

External relations allow to define Collections which will only be available through the "Related Data" section or a given model.

Note that external relations do not support pagination.

<?php

use ForestAdmin\AgentPHP\Agent\Utils\Env;
use ForestAdmin\AgentPHP\DatasourceCustomizer\CollectionCustomizer;
use ForestAdmin\AgentPHP\DatasourceDoctrine\DoctrineDatasource;
use ForestAdmin\SymfonyForestAdmin\Service\ForestAgent;

return static function (ForestAgent $forestAgent) {
    $forestAgent->agent->addDatasource(
        new DoctrineDatasource($forestAgent->getEntityManager(), [
            'url'      => Env::get('DATABASE_URL'),
        ])
    )->customizeCollection('address', function (CollectionCustomizer $builder) {
            $states = [
                [ 'code' => 'AK', 'name' => 'Alaska', 'zipMin' => 99501, 'zipMax' => 99950, 'closeTo' => [] ],
                [ 'code' => 'AL', 'name' => 'Alabama', 'zipMin' => 35004, 'zipMax' => 36925, 'closeTo' => ['TE', 'MI', 'GE', 'FL'] ],
                [ 'code' => 'AR', 'name' => 'Arkansas', 'zipMin' => 71601, 'zipMax' => 72959, 'closeTo' => ['OK', 'TX', 'LO', 'MI'] ],
                [ 'code' => 'AZ', 'name' => 'Arizona', 'zipMin' => 85001, 'zipMax' => 86556, 'closeTo' => ['NM', 'CO', 'UT', 'NE'] ],
                [ 'code' => 'CA', 'name' => 'California', 'zipMin' => 90001, 'zipMax' => 96162, 'closeTo' => ['OR', 'NE', 'AZ'] ],
                // ....
            ];

            $builder->addExternalRelation(
                'nearStates',
                [
                    // Define schema of the records in the relation.
                    'schema' => ['code' => 'String', 'name' => 'String'],

                    // Which fields are needed from the parent record to run the handler?
                    // Dependencies are optional: by default only the primary key of address would be provided
                    'dependencies' => ['country', 'zipCode'],

                    'listRecords' => function ($record) use ($states) {
                        if ($record['country'] === 'USA') {
                            $state = array_filter($states, fn ($s) => $s['zipMin'] < $record['zipCode'] && $record['zipCode'] < $s['zipMax']);
                            $state = array_shift($state);

                            return array_filter($states, fn ($s) => (in_array($s['code'], $state['closeTo'])));
                        }

                        return [];
                    },
                ]
            );
        }
    );
};