Eloquent selfreferencing hierachie to json - php

Question

I'm trying Eloquent now with high expectations.
I have a category tree.
Everything works fine. But now I want to return the whole tree as json. Therefore I'm doing:
$categories = Category::whereNull('parent_id')->get()->toJson();
And only get the adam and eve nodes.
[{"category_id":1,"name":"Boats","slug":"boats","parent_id":null},
{"category_id":2,"name":"Paddles","slug":"paddles","parent_id":null}]
Which is good basically. How to integrate the childs recursivly? No "native" eloquent way for that?
Tree like this:
select * from categories;
+-------------+----------------+----------------+-----------+
| category_id | name | slug | parent_id |
+-------------+----------------+----------------+-----------+
| 1 | Boats | boats | NULL |
| 2 | Paddles | paddles | NULL |
| 3 | Kayaks | kayaks | 1 |
| 4 | Canoes | canoes | 1 |
| 5 | Carbon Paddles | carbon-paddles | 2 |
| 6 | Vajda K1 | vajda-k1 | 4 |
| 7 | Dagger RPM | dagger-rpm | 3 |
| 8 | Kober Viper | vober-viper | 2 |
+-------------+----------------+----------------+-----------+
8 rows in set (0.03 sec)
and a model like that
class Category extends Eloquent {
protected $table = 'categories';
protected $primaryKey = 'category_id';
protected $fillable = array("name", "slug", "parent_id");
public $timestamps = FALSE;
// each category has many subcategories
public function childs() {
return $this->hasMany('Category');
}
// each category belogs to one parent category
public function parent() {
return $this->belongsTo('Category');
}
}

Answer 1

AS far as I know there is no native way to get a recursive result from eloquent directly.
For the first level you would use:
$categories = Category::whereNull('parent_id')->with('childs')->get()->toJson();
For the next level (and likewise further on):
$categories = Category::whereNull('parent_id')->with(['childs' => function ($query) {
$query->with('childs');
}])->get()->toJson();
Using Lazy Eager Loading you'll be able to build your own PHP giveMeMyCatTree() methode.
Does this help?