Laravel Eloquent: belongsToMany to return an array of strings instead of array of objects

Question

I have two tables that are connected with a pivot table.

shows:

+----+--------+
| id | show   |
+----+--------+
|  1 | show1  |
|  2 | show2  |
|  3 | show3  |
+----+--------+

draft_types:

+----+--------+
| id | type   |
+----+--------+
|  1 | type1  |
|  2 | type2  |
|  3 | type3  |
+----+--------+

show_draft_types:

+---------+---------------+
| show_id | draft_type_id |
+---------+---------------+
|  1      | 1             |
|  1      | 2             |
|  1      | 3             |
+---------+---------------+

So essentially a show has many different draft types and here's the relationship that I'm using in eloquent for shows:

public function draft_types()
{
    return $this->belongsToMany('App\Models\DraftTypes', 'show_draft_types', 'show_id', 'draft_type_id');
}

The problem is whenever I do:

Shows::where('id', 1)->with(['draft_types'])->first()

I get this:

{
    id: 1,
    show: "show1",
    draft_types: [
        {
            id: 1,
            type: "type1"
        },
        {
            id: 2,
            type: "type2"
        },
        {
            id: 3,
            type: "type3"
        }
    ]
}

What I want to get is this:

{
    id: 1,
    show: "show1",
    draft_types: [
        "type1",
        "type2",
        "type3"
    ]
}

Is there a way to do this with eloquent relationships?

Answer 1

You could add an appended attribute to the Show model and an accessor for the desired array:

// Show.php

class Show extends Model
{
    protected $appends = ['draft_types_array'];

    public function draft_types()
    {
        return $this->belongsToMany('App\Models\DraftTypes', 'show_draft_types', 'show_id', 'draft_type_id');
    }

    public function getDraftTypesArrayAttribute()
    {
        return $this->draftTypes->pluck('type')->toArray();
    }
}

Usage:

$show = Show::where('id', 1)->with(['draft_types'])->first();

dd($show->draft_types_array);


// Outputs: 
// [
//   "type1",
//   "type2",
//   "type3"
//  ]