yii2/extensions/gii/generators/crud/default/search.php

<?php

use yii\helpers\StringHelper;

/**
 * This is the template for generating CRUD search class of the specified model.
 *
 * @var yii\web\View $this
 * @var yii\gii\generators\crud\Generator $generator
 */

$modelClass = StringHelper::basename($generator->modelClass);
$searchModelClass = StringHelper::basename($generator->searchModelClass);
if ($modelClass === $searchModelClass) {
    $modelAlias = $modelClass . 'Model';
}
$rules = $generator->generateSearchRules();
$labels = $generator->generateSearchLabels();
$searchAttributes = $generator->getSearchAttributes();
$searchConditions = $generator->generateSearchConditions();

echo "<?php\n";
?>

namespace <?= StringHelper::dirname(ltrim($generator->searchModelClass, '\\')) ?>;

use yii\base\Model;
use yii\data\ActiveDataProvider;
use <?= ltrim($generator->modelClass, '\\') . (isset($modelAlias) ? " as $modelAlias" : "") ?>;

/**
 * <?= $searchModelClass ?> represents the model behind the search form about `<?= $generator->modelClass ?>`.
 */
class <?= $searchModelClass ?> extends Model
{
    public $<?= implode(";\n    public $", $searchAttributes) ?>;

    public function rules()
    {
        return [
            <?= implode(",\n            ", $rules) ?>,
        ];
    }

    /**
     * @inheritdoc
     */
    public function attributeLabels()
    {
        return [
<?php foreach ($labels as $name => $label): ?>
            <?= "'$name' => " . $generator->generateString(addslashes($label)) . ",\n" ?>
<?php endforeach; ?>
        ];
    }

    public function search($params)
    {
        $query = <?= isset($modelAlias) ? $modelAlias : $modelClass ?>::find();
        $dataProvider = new ActiveDataProvider([
            'query' => $query,
        ]);

        if (!($this->load($params) && $this->validate())) {
            return $dataProvider;
        }

        <?= implode("\n        ", $searchConditions) ?>

        return $dataProvider;
    }

    protected function addCondition($query, $attribute, $partialMatch = false)
    {
        if (($pos = strrpos($attribute, '.')) !== false) {
            $modelAttribute = substr($attribute, $pos + 1);
        } else {
            $modelAttribute = $attribute;
        }

        $value = $this->$modelAttribute;
        if (trim($value) === '') {
            return;
        }
        if ($partialMatch) {
            $query->andWhere(['like', $attribute, $value]);
        } else {
            $query->andWhere([$attribute => $value]);
        }
    }
}