Intra-data source Relationships

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

We've seen that when building data sources, collections must fulfill the contract they defined when declaring their capabilities.

The same is also true for Intra-data source relationships which are declared on the structure of a collection: declared relations must be handled when processing filters, projection, and aggregations.

In practice

one-to-many and many-to-many relationships do not require additional work: Forest Admin will automatically call the destination collection with a valid filter.

On the other hand, many-to-one and one-to-one relationships require the implementer to make all fields from the target collection available on the source collection (under a prefix).

Example

If a structure declaration contains the following statement

class MyCollection extends Collection
{
    public function __construct(DatasourceContract $datasource)
    {
        parent::__construct(
            $datasource,
            'Movie'
        );

        // [...]

        $this->addField('director', new ManyToOneSchema(
            foreignKey: 'directorId',
            foreignKeyTarget: 'id',
            foreignCollection: 'People'
        ));
    }
}

Then the collection must accept references to fields from the people collection under the director prefix in all method parameters.

use ForestAdmin\AgentPHP\DatasourceToolkit\Components\Caller;
use ForestAdmin\AgentPHP\DatasourceToolkit\Components\Query\ConditionTree\Nodes\ConditionTreeBranch;
use ForestAdmin\AgentPHP\DatasourceToolkit\Components\Query\ConditionTree\Nodes\ConditionTreeLeaf;
use ForestAdmin\AgentPHP\DatasourceToolkit\Components\Query\Filters\PaginatedFilter;
use ForestAdmin\AgentPHP\DatasourceToolkit\Components\Query\Sort;

$dataSource->getCollection('Movie')->list(
    $caller,
    new PaginatedFilter(
        conditionTree: new ConditionTreeBranch(
            aggregator: 'and',
            conditions: [
                new ConditionTreeLeaf(
                    field: 'title',
                    operator: 'Equal',
                    value: 'E.T.'
                ),
                new ConditionTreeLeaf(
                    field: 'director:firstName',
                    operator: 'Equal',
                    value: 'Steven'
                ),
            ],
        ),
        sort: new Sort(
            [
               [
                  'field'     => 'director:birthDate',
                  'ascending' => true,
               ],
            ]
        )
    )
);

should return

{
  "id": 34,
  "title": "E.T",
  "director": { "firstName": "Steven", "lastName": "Spielberg" }
}