/**
  * Creates data provider instance with search query applied
  *
  * @param array $params
  *
  * @return ActiveDataProvider
  */
 public function search($params)
 {
     $query = AuthAssignment::find();
     $dataProvider = new ActiveDataProvider(['query' => $query]);
     $this->load($params);
     if (!$this->validate()) {
         // uncomment the following line if you do not want to return any records when validation fails
         // $query->where('0=1');
         return $dataProvider;
     }
     $query->andFilterWhere(['created_at' => $this->created_at]);
     $query->andFilterWhere(['like', 'item_name', $this->item_name])->andFilterWhere(['like', 'user_id', $this->user_id]);
     return $dataProvider;
 }