kartik\builder\Form::init PHP Method

    public function init()
    {
        parent::init();
        $this->checkFormConfig();
        if (empty($this->columnSize)) {
            $this->columnSize = empty($this->form->formConfig['deviceSize']) ? self::SIZE_SMALL : $this->form->formConfig['deviceSize'];
        }
        if (isset($this->form->type)) {
            $this->_orientation = $this->form->type;
        }
        $this->initOptions();
        $this->registerAssets();
        if ($this->autoGenerateColumns) {
            $cols = count($this->attributes);
            $this->columns = $cols >= self::GRID_WIDTH ? self::GRID_WIDTH : $cols;
        }
        echo Html::beginTag($this->_tag, $this->options) . "\n";
    }