/**
  * Creates data provider instance with search query applied
  *
  * @param array $params
  *
  * @return ActiveDataProvider
  */
 public function search($params)
 {
     $query = Tutorialcategory::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(['id' => $this->id]);
     $query->andFilterWhere(['like', 'category', $this->category]);
     return $dataProvider;
 }
 /**
  * Finds the Tutorialcategory model based on its primary key value.
  * If the model is not found, a 404 HTTP exception will be thrown.
  * @param integer $id
  * @return Tutorialcategory the loaded model
  * @throws NotFoundHttpException if the model cannot be found
  */
 protected function findModel($id)
 {
     if (($model = Tutorialcategory::findOne($id)) !== null) {
         return $model;
     } else {
         throw new NotFoundHttpException('The requested page does not exist.');
     }
 }
<div class="tutorial-form">

    <?php 
$form = ActiveForm::begin(['options' => ['enctype' => 'multipart/form-data']]);
?>

    <div class="row">
        <div class="col-md-6">
            <?php 
echo $form->field($model, 'title')->textInput();
?>
        </div>
        <div class="col-md-6">
            <?php 
echo $form->field($model, 'id_category')->dropDownList(ArrayHelper::map(Tutorialcategory::find()->all(), 'id', 'category'));
?>
        </div>
    </div>

    <div class="row">
        <div class="col-md-6">
            <?php 
echo $form->field($model, 'description')->textArea(['rows' => '6']);
?>
        </div>
        <div class="col-md-6">
            <?php 
echo $form->field($model, 'image')->widget(FileInput::classname(), ['options' => ['accept' => 'image/*']]);
?>
        </div>