Alternative Lookup model in Yii 2

What is the alternative to Lookup model to view dropdownlists from lookup model in Gridview

Like this in Yi 1.1:

?= GridView::widget([

'dataProvider' => $DataProvider,


'columns' => [


       id',


    'exam_name',





       [


        'attribute' => 'exam_nature',


        'value' => 'Lookup::item("ExamNature", $data->exam_nature)',


        'filter' => Lookup::items('ExamNature'),


        ],

];)

?>

If it is relational data, you can access it direct using dot object notation eg




'dataProvider' => $DataProvider,

'columns' => [

id',

'exam_name',

'exam.nature',



If it isn’t relational or your need more flexibility you can it using a callback eg,




[

	'attribute' => 'name',

	'value' => function ($model) {

		return $model->first_name . '  ' . $model->last_name;

	},

]