Get array of Eloquent model's relations

It's not possible because relationships are loaded only when requested either by using with (for eager loading) or using relationship public method defined in the model, for example, if a Author model is created with following relationship

public function articles() {
    return $this->hasMany('Article');
}

When you call this method like:

$author = Author::find(1);
$author->articles; // <-- this will load related article models as a collection

Also, as I said with, when you use something like this:

$article = Article::with('author')->get(1);

In this case, the first article (with id 1) will be loaded with it's related model Author and you can use

$article->author->name; // to access the name field from related/loaded author model

So, it's not possible to get the relations magically without using appropriate method for loading of relationships but once you load the relationship (related models) then you may use something like this to get the relations:

$article = Article::with(['category', 'author'])->first();
$article->getRelations(); // get all the related models
$article->getRelation('author'); // to get only related author model

To convert them to an array you may use toArray() method like:

dd($article->getRelations()->toArray()); // dump and die as array

The relationsToArray() method works on a model which is loaded with it's related models. This method converts related models to array form where toArray() method converts all the data of a model (with relationship) to array, here is the source code:

public function toArray()
{
     $attributes = $this->attributesToArray();

     return array_merge($attributes, $this->relationsToArray());
}

It merges model attributes and it's related model's attributes after converting to array then returns it.

use this:

class Article extends Eloquent 
{
    protected $guarded = array();

    public static $rules = array();

    public $relationships = array('Author', 'Category');

    public function author() {
        return $this->belongsTo('Author');
    }

    public function category() {
        return $this->belongsTo('Category');
    }
}

So outside the class you can do something like this:

public function articleWithAllRelationships()
{
    $article = new Article;
    $relationships = $article->relationships;
    $article = $article->with($relationships)->first();
}