拉拉维尔。在具有关系的模型中使用scope()

我有两个相关模型：Category and Post.

The Post模型有一个published范围（方法scopePublished()).

当我尝试获取该范围内的所有类别时：

$categories = Category::with('posts')->published()->get();

我收到错误：

调用未定义的方法published()

类别：

class Category extends \Eloquent
{
    public function posts()
    {
        return $this->HasMany('Post');
    }
}

Post:

class Post extends \Eloquent
{
   public function category()
   {
       return $this->belongsTo('Category');
   }


   public function scopePublished($query)
   {
       return $query->where('published', 1);
   }

}

您可以内联执行此操作：

$categories = Category::with(['posts' => function ($q) {
  $q->published();
}])->get();

您还可以定义一个关系：

public function postsPublished()
{
   return $this->hasMany('Post')->published();
   // or this way:
   // return $this->posts()->published();
}

进而：

//all posts
$category->posts;

// published only
$category->postsPublished;

// eager loading
$categories->with('postsPublished')->get();