如何过滤 Laravel 中的嵌套集合？

Question

I've been scouring Stack for the last couple of hours, and while several seem related, nothing appears to be working correctly.

I have a GraphQL API running on Laravel, and am trying to filter out the current_user from a mutator so that I don't have to do it on the frontend.

A User hasMany Trips, and each Trip belongsToMany Users via a pivot table called trip_user . On the Trip model, I am eager loading things such as Todos and Users like this:

Trip.php

class Trip extends Model
{
    protected $with = [
        'todos', 'shopping_list_items', 'users'
    ];

    public function users(): BelongsToMany
    {
        return $this->belongsToMany(User::class);
    }

    // other relationships
}

Then in my TripQuery which returns my results to my GraphQL client, I am trying to return all of a user's trips, but filter out current_user, like so:

class TripsQuery
{
    public function find_by_user($rootValue, array $args, GraphQLContext $context, ResolveInfo $resolveInfo)
    {
        $user = $context->user();

        if ($user) {
            // all trip friends and todos automatically eager loaded on the model
            $trips = $user->trips()->get();

            return $trips->each->users->filter(function ($friend) use ($user) {
                return $friend->id !== $user->id;
            });
        }

        return null;
    }
}

When I run this however, the only user it's returning is current_user, and for some reason it's returning an empty array of Todos , even though it should return 4 of them. I'm not sure why the ->filter() function isn't working (I am brand new to Laravel, so there's that).

Why isn't the ->filter working correctly?

EDIT Including the results from a dd() :

array:2 [
  0 => array:9 [
    "id" => 1
    "name" => "Trip 1"
    "description" => "Planning for Trip 1"
    "owner_id" => 1
    "created_at" => "2020-11-18T06:28:45.000000Z"
    "updated_at" => "2020-11-18T06:28:45.000000Z"
    "todos" => array:4 [
      0 => array:6 [
        "id" => 1
        "title" => "Book car rental"
        "checked" => 0
        "trip_id" => 1
        "created_at" => "2020-11-18T17:00:46.000000Z"
        "updated_at" => "2020-11-18T17:00:46.000000Z"
      ]
      1 => array:6 [
        "id" => 2
        "title" => "Check in to flights"
        "checked" => 0
        "trip_id" => 1
        "created_at" => "2020-11-18T17:00:46.000000Z"
        "updated_at" => "2020-11-18T17:00:46.000000Z"
      ]
      2 => array:6 [
        "id" => 3
        "title" => "Drop off dog at sitter"
        "checked" => 1
        "trip_id" => 1
        "created_at" => "2020-11-18T17:00:46.000000Z"
        "updated_at" => "2020-11-18T17:00:46.000000Z"
      ]
      3 => array:6 [
        "id" => 4
        "title" => "Stop at store"
        "checked" => 1
        "trip_id" => 1
        "created_at" => "2020-11-18T17:00:46.000000Z"
        "updated_at" => "2020-11-18T17:00:46.000000Z"
      ]
    ]
    "users" => array:3 [
      0 => array:19 [
        "id" => 1
        "api_token" => null
        "email" => "test@gmail.com"
        "email_verified_at" => "2020-11-07T15:38:48.000000Z"
        "avatar_url" => null
        "created_at" => "2020-11-07T15:38:48.000000Z"
        "updated_at" => "2020-11-16T20:55:02.000000Z"
        "pivot" => array:2 [
          "trip_id" => 1
          "user_id" => 1
        ]
      ]
      1 => array:19 [
        "id" => 2
        "api_token" => null
        "email" => "michael.scott@gmail.com"
        "email_verified_at" => "2020-11-07T15:38:48.000000Z"
        "avatar_url" => null
        "created_at" => "2020-11-07T15:38:48.000000Z"
        "updated_at" => "2020-11-07T15:38:48.000000Z"
        "pivot" => array:2 [
          "trip_id" => 1
          "user_id" => 2
        ]
      ]
      2 => array:19 [
        "id" => 3
        "api_token" => null
        "email" => "pam.beasley@gmail.com"
        "email_verified_at" => "2020-11-07T15:38:48.000000Z"
        "avatar_url" => null
        "created_at" => "2020-11-07T15:38:48.000000Z"
        "updated_at" => "2020-11-07T15:38:48.000000Z"
        "pivot" => array:2 [
          "trip_id" => 1
          "user_id" => 3
        ]
      ]
    ]
  ]
  1 => array:9 [
    "id" => 2
    "name" => "Trip 2"
    "description" => "Trip 2 Description"
    "owner_id" => 1
    "created_at" => "2020-11-18T06:28:45.000000Z"
    "updated_at" => "2020-11-18T06:28:45.000000Z"
    "todos" => []
    "shopping_list_items" => []
    "users" => array:1 [
      0 => array:19 [
        "id" => 1
        "api_token" => null
        "email" => "benny.timkins@gmail.com"
        "email_verified_at" => "2020-11-07T15:38:48.000000Z"
        "avatar_url" => null
        "created_at" => "2020-11-07T15:38:48.000000Z"
        "updated_at" => "2020-11-16T20:55:02.000000Z"
        "pivot" => array:2 [
          "trip_id" => 2
          "user_id" => 1
        ]
      ]
    ]
  ]
]

Answer 1

Each does only return current collection for chaining oportunity, does not mutate the collection .

I think the correct solution from how it looks like you use GraphQL , is to filter the eager loading using the with() method and adding a query to it.

return $user->trips()->with(['users' => function ($query) use ($user) {
    $query->where('id', '!=', $user->id);
}])->get();

For better code style, never check for a condition, invert it and return early.

$user = $context->user();

if (! $user) {
    return null;
}

return $user->trips()->with(['users' => function ($query) use ($user) {
    $query->where('users.id', '!=', $user->id);
}])->get();