common/modules/product/models/BrandSearch.php

<?php

namespace common\modules\product\models;

use yii\base\Model;
use yii\data\ActiveDataProvider;
use yii\db\ActiveQuery;

/**
 * BrandSearch represents the model behind the search form about `common\modules\product\models\Brand`.
 */
class BrandSearch extends Brand
{
    public $brand_name;
    /**
     * @inheritdoc
     */
    public function rules()
    {
        return [
            [['brand_id'], 'integer'],
        ];
    }
    
    public function behaviors()
    {
        return [];
    }
    
    /**
     * @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 = Brand::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;
        }*/

        $dataProvider->setSort([
            'attributes' => [
                'brand_name',
            ],
        ]);

        // grid filtering conditions
        $query->andFilterWhere([
            'brand_id' => $this->brand_id,
        ]);

        $query->orderBy(['brand_id' => SORT_ASC]);

        return $dataProvider;
    }
    
    /**
     * @param null|Category  $category
     * @param array $params
     * @param null|ActiveQuery  $productQuery
     *
     * @return ActiveQuery
     */
    public function getBrands($category = null, $params = [], $productQuery = null) {

        $query = Brand::find()
            ->select([
                Brand::tableName() .'.*'
            ])
            ->innerJoin(Product::tableName(), Product::tableName() .'.brand_id='. Brand::tableName() .'.brand_id')
            ->innerJoin(ProductCategory::tableName(), ProductCategory::tableName() .'.product_id='. Product::tableName() .'.product_id');
        
        $query->innerJoin('product_variant', 'product_variant.product_id = '. Product::tableName() .'.product_id');
        $query->where(['!=', 'product_variant.stock', 0]);
        $query->groupBy(Product::tableName() .'.product_id');
        if (!empty($category)) {
            $query->andWhere([
                ProductCategory::tableName() .'.category_id' => $category->category_id
            ]);
        }
        $query->groupBy(Brand::tableName() .'.brand_id');

        return $query;
    }
}