Is Separate Query Behavior Really Necessary?

[angelcoding]

I'm just wondering why a separate Query behavior is needed when you could simply add those functions to the main AR behavior and just use that without having to extend ActiveQuery and add a second behavior? e.g move roots function to NestedSetsBehavior (would be similar for leaves() function too) ...

    /**
     * Gets root node(s).
     * @return ActiveQuery.
     */
    public function roots()
    {
        $query = $this->owner->find();

        $query->andWhere([$this->leftAttribute => 1])
              ->addOrderBy([$this->owner->primaryKey()[0] => SORT_ASC]);

        return $query;
    }

Am I wrong in thinking this?

[creocoder]

Its absoluttely neccesary. Moreover its normal to have Query model if you want scopes feature for example. Also look query leaves() and roots() usage documentation. Its work like Category::find()->roots() or Category::find()->leaves() while ActiveRecord behavior need instance. We do not have instance in such cases.

[angelcoding]

Aaah OK, thanks for clearing that up. I can see the advantage now when using static class methods.