How to create multidimensional array to put it in dropDownList (yii2)?

Question

Yii

There is a table of news and their categories.
request

find()->with(['category'])->orderBy(['position' => SORT_DESC])->all()

making a connection

public function getCategory()
    {
        return $this->hasOne(NewsCategory::className(), ['id' => 'cat_id']);
    }

I need to get this array

'cat1' => [
                1 => 'news_title1',
                2 => 'In news_title2',        
            ],
            'cat2' => [
                3 => 'news 3',             
            ],

To then output it to dropDownList
Where cat1 is the headings from the category table and news is the headings from the news table,
tell me how to do this?

Answer 1

There are miracles, just wrote on the ball like this
and everything turned out)))

Answer 2

make
helper/CategoryDropDown with toArray(..) method
it returns an array using foreach as an example