Include parameter doesn't work with different type of entities

I don't like adding non-standard parameters for include.

\Drupal\jsonapi\Context\FieldResolver::resolveInternalIncludePath is what throws this error.

    $public_field_name = $path_parts[0];
    $internal_field_name = $resource_type->getInternalName($public_field_name);
    $relatable_resource_types = $resource_type->getRelatableResourceTypesByField($public_field_name);
    if (empty($relatable_resource_types)) {
      $message = "`$public_field_name` is not a valid relationship field name.";
      if (!empty(($possible = implode(', ', array_keys($resource_type->getRelatableResourceTypes()))))) {
        $message .= " Possible values: $possible.";
      }
      throw new CacheableBadRequestHttpException($cacheability, $message);
    }

The exploded paths is the include parameter

    // $include_parameter: 'one.two.three, one.two.four'.
    $include_paths = array_map('trim', explode(',', $include_parameter));
    // $exploded_paths: [['one', 'two', 'three'], ['one', 'two', 'four']].
    $exploded_paths = array_map(function ($include_path) {
      return array_map('trim', explode('.', $include_path));
    }, $include_paths);

So we could follow the patch's approach of iterating over each data, getting the resource type and checking if the include applies to the resource object. Then run \Drupal\jsonapi\JsonApiResource\Data::deduplicate at the end. The main difference if performing the check ourselves versus ignoring the exception.

Maybe we should provide our own include resolver which wraps \Drupal\jsonapi\IncludeResolver and supports missing relationships, only for jsonapi_resources resources. But I feel like there should still be some kind of error if a relationship is requested that doesn't exist, at all. Maybe.

Instead of checking the resource types in the data, we could just check the resource types defined by the route? However, \Drupal\jsonapi_resources\Unstable\ResourceResponseFactory::create is not aware of the resource types used. 💡 but \Drupal\jsonapi_resources\Unstable\DocumentExtractor::extractResourceObject does this, which it also could!

    /** @var \Drupal\jsonapi\ResourceType\ResourceType[] $route_resource_types */
    $route_resource_types = $request->attributes->get('resource_types');

Okay, I came back to this later than I wanted to, but I have an MR opened with a failing test.

Okay, I'm happy with the MR and approach.

mglaman → credited japerry → .

Saving issue credits. japerry helped review

Automatically closed - issue fixed for 2 weeks with no activity.