如何将不同的Eloquent模型注入特征方法？

Question

I am looking to stay DRY across controllers in my Laravel 5 application. The route I have chosen is to use a Trait with methods that I can apply to my separate controllers.

The methods in my Trait need to act upon different Model classes. They are always subclasses of the Eloquent model.

Here was my attempt:

<?php namespace Conjunto\Traits;

use Illuminate\Database\Eloquent\Model;

trait SortableTrait
{
    /**
     *
     */
    public function upPosition(Model $model)
    {
        dd($model);
    }
}

I am unfortunately getting the following error, since the Eloquent Model itself is not instantiable:

Target [Illuminate\Database\Eloquent\Model] is not instantiable.

How could I still make this work with a Trait?

Answer 1

The solution is injecting concrete model in constructor, setting it as property and using this property in upPosition method of your Trait.

controller UserController 
{
  protected $model;

  use SortableTrait;

  public function __construct(User $user) 
  {
    $this->model = $user;
  }
}

and now in your Trait you should change your method into:

public function upPosition()
{
   dd($this->model);
}