common/modules/product/models/ProductSearch.php

<?php
namespace common\modules\product\models;
use Yii;
use yii\base\Model;
use yii\data\ActiveDataProvider;
use common\modules\product\models\Product;
use yii\web\NotFoundHttpException;
/**
 * ProductSearch represents the model behind the search form about `common\modules\product\models\Product`.
 */
class ProductSearch extends Product
{
    /**
     * @inheritdoc
     */
    public function rules()
    {
        return [
            [['name'], 'safe'],
            [['tax_brand_id', 'product_id'], 'integer'],
        ];
    }
    /**
     * @inheritdoc
     */
    public function scenarios()
    {
        // bypass scenarios() implementation in the parent class
        return Model::scenarios();
    }
    /**
     * Creates data provider instance with search query applied
     *
     * @param array $params
     *
     * @return ActiveDataProvider
     */
    public function search($params)
    {
        $query = Product::find();
        // add conditions that should always apply here
        $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;
        }
        // grid filtering conditions
        $query->andFilterWhere([
            'tax_brand_id' => $this->tax_brand_id,
            'product_id' => $this->product_id,
        ]);
        $query->andFilterWhere(['like', 'name', $this->name]);
        return $dataProvider;
    }
    public static function findByAlias($alias) {
        /** @var ProductQuery $query */
        $query = Product::find();
        $query->byAlias($alias);
        if (($model = $query->one()) !== null) {
            return $model;
        } else {
            throw new NotFoundHttpException('The requested product does not exist.');
        }
    }
}