src/widget/CheckboxColumn.php
public function createUrl($action, $model, $key, $index)
    {
        if ($this->urlCreator instanceof Closure) {
            return call_user_func($this->urlCreator, $action, $model, $key, $index);
        } else {
            $params[0] = $this->controller ? $this->controller . '/' . $action : $action;
            return Url::toRoute($params);
        }
    }
public function createUrl($action, $model, $key, $index)
    {
        if ($this->urlCreator instanceof Closure) {
            return call_user_func($this->urlCreator, $action, $model, $key, $index);
        } else {
            $params[0] = $this->controller ? $this->controller . '/' . $action : $action;
            return Url::toRoute($params);
        }
    }
Creates a URL for the given action and model.
This method is called for each button and each row.
@param string $action the button name (or action ID)
@param \yii\db\ActiveRecord $model the data model
@param mixed $key the key associated with the data model
@param integer $index the current row index
@return string the created URL