The filter does not work correctly, all products are pulled out, even if the authors are not attached. What is the best way to make a filter?

Question

API

I want to make a filter, a many-to-many relationship
. Products are linked to categories, their authors are linked to certain products (There may be several of them)
in json I want to display a collection of products with selected authors,

for example:

a filter is made for 1 category, the id of the author of the product is selected in the filter, for example 1 or 1 and 2, etc.

and you need to display the category itself + only products that have authors from the filter
, for some reason I pull out all the products

public function filter($category)
    {
        $sortDirection = 'desc';
        $tags = ['1','2'];
 
        return CategoryResource::collection(Category::with(['products.authors' => function ($query) use ($sortDirection,$tags) {
            $query->whereIn('user_id', $tags)->orderBy('id', $sortDirection);
        }])
            ->where('id',$category)
            ->get());
 
    }

Category Model

public function products() {
        return $this->hasMany(Product::class);
    }

Products Model

public function authors() {
        return $this->belongsToMany(User::class,'product_user','product_id');
    }

What is output from me

"id": 2,
            "name": "Категория 1 ",
            "count": 2,
            "products": [
                {
                    "id": 2,
                    "name": "Товар 1",
                    "description": "Описание",
                    "authors": [
                        {
                            "id": 1,
                            "firstname": "Ivanov 1",
                            "lastname": "Ivanov 1",
                        },
                        {
                            "id": 2,
                            "firstname": "lan",
                            "lastname": "lanov",
                        }
                    ]
                },
                {
                    "id": 2,
                    "name": "Товар 2",
                    "description": "Описание",
                    "authors": []
                }
            ]

"Product 2" has no associated authors
And when I specify, everything is displayed the same, but there is no author in product 1
$tags = ['1'];

"id": 2,
                    "name": "Товар 1",
                    "description": "Описание",
                    "authors": [
                        {
                            "id": 1,
                            "firstname": "Ivanov 1",
                            "lastname": "Ivanov 1",
                        },

Answer 1

The with method does not filter data - it only filters relationships
. To get the data you need, you need to use whereHas

with(['products' => function ($query) use ($sortDirection, $tags) {
        $query->whereHas('authors' ,function ($q) use ($tags) {
                $query->whereIn('user_id', $tags);
        })->orderBy('id', $sortDirection);
}])