frontend/widgets/Nav.php

<?php
    /**
     * Created by PhpStorm.
     * User: stes
     * Date: 25.05.18
     * Time: 17:55
     */
    
    namespace frontend\widgets;
    
    use yii\helpers\Html;
    use yii\helpers\ArrayHelper;
    class Nav extends \yii\bootstrap\Nav
    {
        # метод почти полностью повторяет родительский,
        # различия работы см.в return
        public function renderItem($item)
        {
            if (is_string($item)) {
                return $item;
            }
            if (!isset($item['label'])) {
                throw new InvalidConfigException("The 'label' option is required.");
            }
            $encodeLabel = isset($item['encode']) ? $item['encode'] : $this->encodeLabels;
            $label = $encodeLabel ? Html::encode($item['label']) : $item['label'];
            $options = ArrayHelper::getValue($item, 'options', []);
            $items = ArrayHelper::getValue($item, 'items');
            $url = ArrayHelper::getValue($item, 'url', '#');
            $linkOptions = ArrayHelper::getValue($item, 'linkOptions', []);
            if (isset($item['active'])) {
                $active = ArrayHelper::remove($item, 'active', false);
            } else {
                $active = $this->isItemActive($item);
            }
            if (empty($items)) {
                $items = '';
            } else {
                $linkOptions['data-toggle'] = 'dropdown';
                Html::addCssClass($options, ['widget' => 'dropdown']);
                Html::addCssClass($linkOptions, ['widget' => 'dropdown-toggle']);
                if ($this->dropDownCaret !== '') {
                    $label .= ' ' . $this->dropDownCaret;
                }
                if (is_array($items)) {
                    $items = $this->isChildActive($items, $active);
                    $items = $this->renderDropdown($items, $item);
                }
            }
            if ($active) {
                Html::addCssClass($options, 'active');
            }
            return ($url!=='')?
                Html::tag('li', Html::a($label, $url, $linkOptions) . $items, $options)
                : Html::tag('li', Html::a($label, null, $linkOptions) . $items, $options)
                ;
        }
        public function init()
        {
            foreach ($this->items as &$item)
            {
                if($item['url']===false)$item['url']='';
            }
            if ($this->route === null && \Yii::$app->controller !== null) {
                $this->route = \Yii::$app->controller->getRoute();
            }
            if ($this->params === null) {
                $this->params = \Yii::$app->request->getQueryParams();
            }
            if ($this->dropDownCaret === null) {
                $this->dropDownCaret = '<span class="caret"></span>';
            }
            Html::addCssClass($this->options, []);
        }
    }