Read implementation

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

Developing your query translation layer is much easier when you can preview your work and have intermediary deliverables.

Emulation comes to the rescue: all features that need to be implemented when making a translating data source can be emulated inside your Node.js, at the cost of performance.

This enables you to be up and running in minutes and then optimize your code as you go.

<?php

use ForestAdmin\AgentPHP\DatasourceToolkit\Collection;
use ForestAdmin\AgentPHP\DatasourceToolkit\Components\Caller;
use ForestAdmin\AgentPHP\DatasourceToolkit\Components\Query\Aggregation;
use ForestAdmin\AgentPHP\DatasourceToolkit\Components\Query\Filters\Filter;
use ForestAdmin\AgentPHP\DatasourceToolkit\Components\Query\Projection\Projection;

/**
 * This collection will have terrible performance, but is perfect to test that the
 * structure declaration is well done.
 */
class MyCollection extends Collection
{
    // [... Declare structure and capabilities]
    //  $this->client = new \GuzzleHttp\Client([...]);

    public function list(Caller $caller, Filter $filter, Projection $projection): array
    {
        // Fetch all records on all requests (this is _very_ inefficient)
        try {
            $response = $this->client->get('https://my-api/my-collection');
            $result = json_decode($response->getBody()->getContents(), true)['items'] ?? [];

            if ($filter->getConditionTree()) {
                $result = $filter->getConditionTree()->apply($response, $this, $caller->getTimezone());
            }
            if ($filter->getSort()) {
                $result = $filter->getSort()->apply($result);
            }
            if ($filter->getPage()) {
                $result = $filter->getPage()->apply($result);
            }
            if ($filter->getSegment()) {
                throw new \RuntimeException('This collection does not implements native segments');
            }
            if ($filter->getSearch()) {
                throw new \RuntimeException('This collection is not natively searchable');
            }

            return $projection->apply($result);
        } catch (\Exception $e) {
            throw new \RuntimeException('Failed to fetch or process items: ' . $e->getMessage());
        }
    }

    public function aggregate(Caller $caller, Filter $filter, Aggregation $aggregation, ?int $limit = null)
    {
        // Fetch all records which should be aggregated
        $records = $this->list($caller, $filter, $aggregation->getProjection());

        return $aggregation->apply($records, $caller->getTimezone(), $limit);
    }

Tips

Count queries

The aggregate method is used by Forest Admin both to count records and to extract the data which is needed to generate charts.

If the API/Database you are targeting has an efficient API that is made for counting records, you may want to handle this case first.

<?php

use ForestAdmin\AgentPHP\DatasourceToolkit\Collection;
use ForestAdmin\AgentPHP\DatasourceToolkit\Components\Caller;
use ForestAdmin\AgentPHP\DatasourceToolkit\Components\Query\Aggregation;
use ForestAdmin\AgentPHP\DatasourceToolkit\Components\Query\Filters\Filter;
use ForestAdmin\AgentPHP\DatasourceToolkit\Components\Query\Projection\Projection;

class MyCollection extends Collection
{
    // [... Declare structure, capabilities and list method]
    //  $this->client = new \GuzzleHttp\Client([...]);

    public function aggregate(Caller $caller, Filter $filter, Aggregation $aggregation, ?int $limit = null)
    {
        if ($aggregation->getOperation() === 'Count' && empty($aggregation->getGroups()) && ! $aggregation->getField()) {
            return [
                ['value' => $this->count($caller, $filter)],
            ];
        }

        // [... handle the general case]
    }

    public function count(Caller $caller, Filter $filter)
    {
        $response = $this->client->get('https://my-api/my-collection/count', [
            'query' => ['filter' => $this->translateFilter($caller, $filter)],
        ]);

        return json_decode($response->getBody()->getContents(), true)['count'];
    }

    private function translateFilter(Caller $caller, Filter $filter)
    {
        // [... translate filter]
    }
}