Laravel Eloquent group by with pivot table & relations - laravel

Question

I have this platform I'm creating for foodtruck events. There is a pool of exhibitors who attend several events. Each foodtruck has it's own menu of dishes that they serve, in several categories.
The problem / what I'd like to achieve
I would like to make a menu for each event, looping through all
exhibitors (who attend) and then showing the dishes by category.
Something like this;
/menu/{eventid}
Dish category 1
dish from exhibitor A
dish from exhibitor B
Dish category 2
dish from exh A
dish from exh C
dish from exh D
...
Models
Event model
class Event extends Model
{
protected $table = "events";
public function exhibitors()
{
return $this->belongsToMany('App\Exhibitor', 'events_exhibitors');
}
Dish model
class Dish extends Model
{
//
protected $table = "dishes";
public function category()
{
return $this->hasOne('App\Category', 'id', 'category_id');
}
public function exhibitor()
{
return $this->belongsTo('App\Exhibitor');
}
}
Exhibitor model
class Exhibitor extends Model
{
protected $table = "exhibitors";
public function events()
{
return $this->belongsToMany('App\Event', 'events_exhibitors');
}
public function dishes()
{
return $this->hasMany('App\Dish');
}
}
Database structure
There is a pivot table to register which foodtrucks go to which events. So far, I think (hope) my relations are working. I hope this image shows enough;
What I've tried
I've tried several things but I think my insight in Laravel eloquent lacks to understand the logic behind this issue.
$dishes = Event::where('id', $id)
->with(['exhibitors.dishes' => function($q) {
$q->select('dishes.dish_data');
}])->get();
Or
$dishes = Event::with(array('exhibitor.dish') => function($query) use ($sub){
$query->where('name',$sub);}))->get();
I have absolutely no clue how to accomplish this by Eloquent or how this would work in the view.

Answer 1

Try something like this:
It will get all the ids of the exhibitors that are connected to the event.
Then it will get all categories where the connected dishes have an exhibitor_id that is in the array of exhibitor ids.
Category Model
class Category extends Model
{
protected $table = "categories";
public function dishes()
{
return $this->hasMany('App\Dish', 'category_id');
}
}
Controller Action
$event = Event::findOrFail($id);
$exhibitorIds = $event->exhibitors()->select('exhibitors.id')->get()->pluck('id')->all();
$categories = Category::whereHas('dishes', function($query) use ($exhibitorIds) {
$query->whereIn('exhibitor_id', $exhibitorIds);
})->with(['dishes' => function($query) use ($exhibitorIds) {
$query->whereIn('exhibitor_id', $exhibitorIds);
}])->get();
return view('events.menu', compact('event', 'categories') );
View
#foreach($categories as $category)
<h2>{{ $category->name }}</h2>
<ul>
#foreach($category->dishes as $dish)
<li>{{ $dish->dish_data }}</li>
#endforeach
</ul>
#endforeach