Having one and only one Collection Data provider for each resource is a must?

[mappedinn]

Hi,

I do need custom operation in my API which returns an entity for given slug. Consequently, the total number of operations for the resource Product are 6 (5 are default operations + 1 custom operation).

  api_products_get_collection             GET        ANY      ANY    /api/products.{_format}                
  api_products_post_collection            POST       ANY      ANY    /api/products.{_format}                
  api_products_get_item                   GET        ANY      ANY    /api/products/{id}.{_format}           
  api_products_put_item                   PUT        ANY      ANY    /api/products/{id}.{_format}           
  api_products_delete_item                DELETE     ANY      ANY    /api/products/{id}.{_format}           
  api_products_slug                       GET        ANY      ANY    /api/products/by-slug/{slug} 

I followed the official documentation to define the custom operation. But surprisingly, I noticed that the route api_products_get_collection is using the collection data provider of the route api_products_slug.

I thought at first it is problem of routes order. But, it was not the case since as it is shown in the command below:

$ bin/console debug:router | grep products 
  app_product_products                    ANY        ANY      ANY    /                                      
  api_products_get_collection             GET        ANY      ANY    /api/products.{_format}                
  api_products_post_collection            POST       ANY      ANY    /api/products.{_format}                
  api_products_get_item                   GET        ANY      ANY    /api/products/{id}.{_format}           
  api_products_put_item                   PUT        ANY      ANY    /api/products/{id}.{_format}           
  api_products_delete_item                DELETE     ANY      ANY    /api/products/{id}.{_format}           
  api_products_slug                       GET        ANY      ANY    /api/products/by-slug/{slug}

In addition, here is how I declared the routes:

api_platform:
    resource: .
    type: api_platform
    prefix: /api

# the routes is declared after the routes of the api_platfom to make sure having to the custom operation route after api_platfom routes
actions:
    resource: ../../src/Action/
    type: annotation

So, for sure, it is not a problem related to the order of routes.

The question is: should I have one and only one Collection Data Provider for each resource?

---

Below is how I declared the custom operation.

(1) Declaration of a provider implementing CollectionDataProviderInterface

<?php

namespace App\Provider;

use App\Entity\Product;
use ApiPlatform\Core\DataProvider\CollectionDataProviderInterface;
use ApiPlatform\Core\Exception\ResourceClassNotSupportedException;
use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;

use App\Repository\ProductRepository;
use Symfony\Component\HttpFoundation\RequestStack;
use Monolog\Logger;

final class ProductCollectionDataProvider implements CollectionDataProviderInterface
{
    /**
     * @var ProductRepository
     */
    private $repository;

    /**
     * @var RequestStack
     */
    private $requestStack;

    /**
     * @var Logger
     */
    private $logger;

    /**
     * ProductCollectionDataProviderconstructor.
     *
     * @param ProductRepository $repository
     * @param RequestStack $requestStack
     * @param Logger $logger
     */
    public function __construct(ProductRepository $repository, RequestStack $requestStack, Logger $logger)
    {
        $this->repository = $repository;
        $this->requestStack = $requestStack;
        $this->logger = $logger;
    }

    /**
     * Retrieves a collection.
     *
     * @param string      $resourceClass
     * @param string|null $operationName
     *
     * @throws ResourceClassNotSupportedException
     *
     * @return array|\Traversable
     */
    public function getCollection(string $resourceClass, string $operationName = null){

        $this->logger->info('getCollection() is called');
        $slug =  $this->requestStack->getCurrentRequest()->attributes->get('slug');
        $this->logger->info($slug);

        if (Product::class !== $resourceClass) {
            throw new ResourceClassNotSupportedException();
        }
        // if($operationName !== 'product_slug') return null;

        $product = $this->repository->findProductBySlug($this->requestStack->getCurrentRequest()->attributes->get('slug'));
        if($product===null){
            throw new NotFoundHttpException(sprintf('The Product resource \'%s\' was not found.',$slug));

        }
        return $product;

    }

}

(2) Definition of an action

<?php

namespace App\Action;

use App\Entity\Product;
use App\Provider\ProductCollectionDataProvider;
use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
use Sensio\Bundle\FrameworkExtraBundle\Configuration\Method;
use Symfony\Component\Routing\Annotation\Route;

class ProductSlug
{
    private $productCollectionDataProvider;

    public function __construct(ProductCollectionDataProvider $productCollectionDataProvider)
    {
        $this->productCollectionDataProvider = $productCollectionDataProvider;
    }

    /**
     * @Route(
     *     name="api_products_slug",
     *     path="/api/products/by-slug/{slug}",
     *     defaults={"_api_resource_class"=Product::class, "_api_collection_operation_name"="product_slug"}
     * )
     * @Method("GET")
     */
    public function __invoke()
    {
        return  $this->productCollectionDataProvider->getCollection(Product::class);
    }
}

(3) declaration of the custom action as an service

services:
    # ...
    App\Action\:
        resource: '../src/Action'
        tags: ['controller.service_arguments']

(4) declaration of the route of the custom action

api_platform:
    resource: .
    type: api_platform
    prefix: /api

# the routes is declared after the routes of the api_platfom to make sure having to the custom operation route after api_platfom routes
actions:
    resource: ../../src/Action/
    type: annotation

environment

$ composer info | grep api
api-platform/api-pack             v1.0.1             A pack for API Platform
api-platform/core                 v2.1.5             The ultimate solution to create web APIs.
$ composer info | grep symfony/framework
symfony/framework-bundle          v4.0.4             Symfony FrameworkBundle

[mappedinn]

@dunglas @theofidry @soyuka I need just to my understanding by yes or no.

Thanks...

[soyuka]

@dunglas @theofidry @soyuka I need just to my understanding by yes or no.
Thanks...

Reading this post for the first time and this makes I don't really want to answer now... Just a reminder this is an open source project and everyone is there on his own free time.

should I have one and only one Collection Data Provider for each resource?

You don't have to but you can. Your implementation looks correct. If you want to use a by-slug operation on many resources you may just use the same data provider. I'd implement an interface (eg SluggedEntityInterface) and you could test is_subclass_of($request->attributes->get('_api_resource_class'), SluggedEntityInterface::class).

[mappedinn]

Reading this post for the first time and this makes I don't really want to answer now... Just a reminder this is an open source project and everyone is there on his own free time.

Thank you so much for your time. I appreciate.

You don't have to but you can. Your implementation looks correct. If you want to use a by-slug operation on many resources you may just use the same data provider. I'd implement an interface (eg SluggedEntityInterface) and you could test is_subclass_of($request->attributes->get('_api_resource_class'), SluggedEntityInterface::class).

I will implement your test & I will give my feedback.

Thanks again

[mappedinn]

I am back again with my feed back @soyuka

You don't have to but you can. Your implementation looks correct. If you want to use a by-slug operation on many resources you may just use the same data provider. I'd implement an interface (eg SluggedEntityInterface) and you could test is_subclass_of($request->attributes->get('_api_resource_class'), SluggedEntityInterface::class).

The test is_subclass_of($request->attributes->get('_api_resource_class') is same as testing Product::class !== $resourceClass

---

To make sure that collection data provider ProductCollectionDataProvider is only called for the operation product_slug (my custom operation), I just added a simple test $operationName === 'product_slug'

The code became then:

final class ProductCollectionDataProvider implements CollectionDataProviderInterface {

  // ...
    /**
     * Retrieves a collection.
     *
     * @param string      $resourceClass
     * @param string|null $operationName
     *
     * @throws ResourceClassNotSupportedException
     *
     * @return array|\Traversable
     */
    public function getCollection(string $resourceClass, string $operationName = null) {

        if (Product::class !== $resourceClass) {
            throw new ResourceClassNotSupportedException();
        }

        $slug = $this->requestStack->getCurrentRequest()->attributes->get('slug');
        $this->logger->info("*****************getCollection() is called******************");
        $this->logger->info("(*) operationName='$operationName', resourceClass='$resourceClass', slug='$slug'");


        if ($operationName === 'product_slug') {
             $this->logger->info("(IF) operationName=$operationName");
            $product = $this->repository->findProductBySlug($slug);
            if ($product === null) {
                throw new NotFoundHttpException(sprintf('The Product resource \'%s\' was not found.', $slug));
            }
            return $product;
        } else {
            $this->logger->info("(ELSE) operationName=$operationName");
            return $this->repository->findAll();
        };
    }

}

The result surprised me. For just one call to the custom operation, the method getCollection() got called twice.

For the first call, the parameters are correct:

• operationName='product_slug'
• resourceClass='App\Entity\Product'
• slug='iphone-x'

But, for the second call, not all the parameters are correct:

• operationName=''
• resourceClass='App\Entity\Product'
• slug='iphone-x'

Below is what the @logger showed.

INFO05:35:57 | app | *****************getCollection() is called******************
INFO05:35:57 | app | (*) operationName='product_slug', resourceClass='App\Entity\Product', slug='iphone-x'
INFO05:35:57 | app | (IF) operationName=product_slug
INFO05:35:57 | app | *****************getCollection() is called******************
INFO05:35:57 | app | (*) operationName='', resourceClass='App\Entity\Product', slug='iphone-x'
INFO05:35:57 | app | (ELSE) operationName=

CRITICAL05:18:19 | request | Uncaught PHP Exception ApiPlatform\Core\Exception\InvalidArgumentException: "Unable to generate an IRI for "App\Entity\Product"." at /home/amine/docker-projects/sf-flex-40/vendor/api-platform/core/src/Bridge/Symfony/Routing/IriConverter.php line 116
-- | -- | --

The question is: Is it normal to get for just one API call two calls to the collection data provider? Is it a bug?

Merci beaucoup @soyuka for your feedback

[mappedinn]

I just wanted to to notice that avoiding testing against the operation name $operationName === 'product_slug' will allow me to get the expected result for the custom operation product_slug .

Nevertheless, the collection data provider will be even used for the collection operation GET which is not expected.

final class ProductCollectionDataProvider implements CollectionDataProviderInterface {
   //  ....
    public function getCollection(string $resourceClass, string $operationName = null) {

        if (Product::class !== $resourceClass) {
            throw new ResourceClassNotSupportedException();
        }

        $slug = $this->requestStack->getCurrentRequest()->attributes->get('slug');
        $this->logger->info("*****************getCollection() is called******************");
        $this->logger->info("(*) operationName='$operationName', resourceClass='$resourceClass', slug='$slug'");

        $product = $this->repository->findProductBySlug($slug);
        if ($product === null) {
            throw new NotFoundHttpException(sprintf('The Product resource \'%s\' was not found.', $slug));
        }
        return $product;
    }

}

And as I noticed in my previous post, a single call to the custom operation will make the collection data provider called twice.

INFO07:34:02 | security | Populated the TokenStorage with an anonymous Token.
-- | -- | --
INFO07:34:02 | app | *****************getCollection() is called******************
INFO07:34:02 | app | (*) operationName='product_slug', resourceClass='App\Entity\Product', slug='iphone-x'
INFO07:34:02 | app | *****************getCollection() is called******************
INFO07:34:02 | app | (*) operationName='', resourceClass='App\Entity\Product', slug='iphone-x'

Encore un grand merci...

[soyuka]

1. Do you have access to the RestrictedDataProviderInterface? It's better to implement this if you can.

Is it normal to get for just one API call two calls to the collection data provider? Is it a bug?

It is if the DataProvider gets called by our ReadListener and by your custom Action.
You can either:

• avoid using an action
• use receive = 0 in the resources attributes to pass this condition

3. You need to use the operationName as a condition for your data provider.

[mappedinn]

Thank @soyuka

Do you have access to the RestrictedDataProviderInterface? It's better to implement this if you can.

I will make a trial

avoid using an action

This means, controllers have to be used. But, I will have to declare the routes of the custom operations in the same file of the routes for api_platform (which is not very clean way for declaring a big list of routes)

use receive = 0 in the resources attributes to pass this condition

Any example available or a link?

You need to use the operationName as a condition for your data provider.

For sure.

[soyuka]

This means, controllers have to be used. But, I will have to declare the routes of the custom operations in the same file of the routes for api_platform (which is not very clean way for declaring a big list of routes)

Okay so just don't call the data provider there, take this one for example:

https://github.com/api-platform/core/blob/master/src/Action/PlaceholderAction.php

It's the default action for every api platform route. You can check the request parameters in the data provider directly.

Any example available or a link?

 * @Route("/api/user_users/{id}/reload", defaults={"_api_resource_class"=User::class, "_api_item_operation_name"="reload", "_api_receive"=false})

It's written somewhere in this part of the documentation

[Simperfit]

If you still have a question, please feel free to ping me.

[chinbaap]

I have 2 custom collection data providers. When i call service A which supposed to call A's data provider , it is trying to call data provider B of service B which eventually throwing DBAL exception.

my config is :

` App\DataProvider\PtUserCardCollectionDataProvider:
tags: [ { name: 'api_platform.pt_user_card_collection_data_provider', priority: 2 } ]
# Autoconfiguration must be disabled to set a custom priority
autoconfigure: false

App\DataProvider\PtUserCollectionDataProvider:
tags: [ { name: 'api_platform.pt_user_collection_data_provider', priority: 4 } ]
autoconfigure: false
`
So confusing. Any solutions, everyone?