Nette\Forms\Form::getRenderer PHP Method

    public function getRenderer()
    {
        if ($this->renderer === NULL) {
            $this->renderer = new Rendering\DefaultFormRenderer();
        }
        return $this->renderer;
    }

 private function setupRenderersLayout()
 {
     $renderer = $this->form->getRenderer();
     if ($renderer instanceof DefaultFormRenderer) {
         $renderer->wrappers['controls']['container'] = NULL;
         $renderer->wrappers['pair']['container'] = 'div class=form-group';
         $renderer->wrappers['pair']['.error'] = 'has-error';
         $renderer->wrappers['control']['container'] = 'div class=col-sm-9';
         $renderer->wrappers['label']['container'] = 'div class="col-sm-3 control-label"';
         $renderer->wrappers['control']['description'] = 'span class=help-block';
         $renderer->wrappers['control']['errorcontainer'] = 'span class=help-block';
     }
 }