invoiceninja/app/Models/Quote.php

<?php

namespace App\Models;

use App\Models\Filterable;
use App\Utils\Traits\MakesHash;
use Illuminate\Database\Eloquent\Model;

class Quote extends BaseModel
{
    use MakesHash;
    use Filterable;

	protected $guarded = [
		'id',
	];

    protected $casts = [
        'settings' => 'object'
    ];
    
    const STATUS_DRAFT = 1;
    const STATUS_SENT =  2;
    const STATUS_APPROVED = 3;
    const STATUS_EXPIRED = -1;

    public function company()
    {
        return $this->belongsTo(Company::class);
    }

    public function user()
    {
        return $this->belongsTo(User::class);
    }

    public function invitations()
    {
        return $this->hasMany(QuoteInvitation::class);
    }

    public function documents()
    {
        return $this->morphMany(Document::class, 'documentable');
    }

}