/**
  * Renders tab items as specified on [[items]].
  *
  * @return string the rendering result.
  * @throws InvalidConfigException.
  */
 protected function renderItems()
 {
     $headers = [];
     $panes = [];
     if (!$this->hasActiveTab() && !empty($this->items)) {
         $this->items[0]['active'] = true;
     }
     foreach ($this->items as $n => $item) {
         if (!array_key_exists('label', $item)) {
             throw new InvalidConfigException("The 'label' option is required.");
         }
         $encodeLabel = isset($item['encode']) ? $item['encode'] : $this->encodeLabels;
         $label = $encodeLabel ? Html::encode($item['label']) : $item['label'];
         $headerOptions = array_merge($this->headerOptions, ArrayHelper::getValue($item, 'headerOptions', []));
         $linkOptions = array_merge($this->linkOptions, ArrayHelper::getValue($item, 'linkOptions', []));
         if (isset($item['items'])) {
             $label .= ' <b class="caret"></b>';
             Html::addCssClass($headerOptions, 'dropdown');
             if ($this->renderDropdown($n, $item['items'], $panes)) {
                 Html::addCssClass($headerOptions, 'active');
             }
             Html::addCssClass($linkOptions, 'dropdown-toggle');
             $linkOptions['data-toggle'] = 'dropdown';
             $header = Html::a($label, "#", $linkOptions) . "\n" . Dropdown::widget(['items' => $item['items'], 'view' => $this->getView()]);
         } else {
             $options = array_merge($this->itemOptions, ArrayHelper::getValue($item, 'options', []));
             $options['id'] = ArrayHelper::getValue($options, 'id', $this->options['id'] . '-tab' . $n);
             Html::addCssClass($options, 'tab-pane');
             if (ArrayHelper::remove($item, 'active')) {
                 Html::addCssClass($options, 'active');
                 Html::addCssClass($headerOptions, 'active');
             }
             $linkOptions['data-toggle'] = 'tab';
             $header = Html::a($label, '#' . $options['id'], $linkOptions);
             if ($this->renderTabContent) {
                 $panes[] = Html::tag('div', isset($item['content']) ? $item['content'] : '', $options);
             }
         }
         $headers[] = Html::tag('li', $header, $headerOptions);
     }
     return Html::tag('ul', implode("\n", $headers), $this->options) . ($this->renderTabContent ? "\n" . Html::tag('div', implode("\n", $panes), ['class' => 'tab-content']) : '');
 }
 /**
  * Renders menu items.
  *
  * @param array $items the menu items to be rendered
  * @param array $options the container HTML attributes
  * @return string the rendering result.
  * @throws InvalidConfigException if the label option is not specified in one of the items.
  */
 protected function renderItems($items, $options = [])
 {
     $lines = [];
     foreach ($items as $i => $item) {
         if (isset($item['visible']) && !$item['visible']) {
             unset($items[$i]);
             continue;
         }
         if (is_string($item)) {
             $lines[] = $item;
             continue;
         }
         if (!array_key_exists('label', $item)) {
             throw new InvalidConfigException("The 'label' option is required.");
         }
         $encodeLabel = isset($item['encode']) ? $item['encode'] : $this->encodeLabels;
         $label = $encodeLabel ? Html::encode($item['label']) : $item['label'];
         $itemOptions = ArrayHelper::getValue($item, 'options', []);
         $linkOptions = ArrayHelper::getValue($item, 'linkOptions', []);
         $linkOptions['tabindex'] = '-1';
         $url = array_key_exists('url', $item) ? $item['url'] : null;
         if (empty($item['items'])) {
             if ($url === null) {
                 $content = $label;
                 Html::addCssClass($itemOptions, 'dropdown-header');
             } else {
                 $content = Html::a($label, $url, $linkOptions);
             }
         } else {
             $submenuOptions = $options;
             unset($submenuOptions['id']);
             $content = Html::a($label, $url === null ? '#' : $url, $linkOptions) . $this->renderItems($item['items'], $submenuOptions);
             Html::addCssClass($itemOptions, 'dropdown-submenu');
         }
         $lines[] = Html::tag('li', $content, $itemOptions);
     }
     return Html::tag('ul', implode("\n", $lines), $options);
 }