Class yii\bootstrap4\Carousel

                public function init()
{
    parent::init();
    Html::addCssClass($this->options, ['widget' => 'carousel slide']);
    if ($this->crossfade) {
        Html::addCssClass($this->options, ['animation' => 'carousel-fade']);
    }
}

            

                public function renderControls()
{
    if (isset($this->controls[0], $this->controls[1])) {
        return Html::a($this->controls[0], '#' . $this->options['id'], [
                'class' => 'carousel-control-prev',
                'data-slide' => 'prev',
                'role' => 'button'
            ]) . "\n"
            . Html::a($this->controls[1], '#' . $this->options['id'], [
                'class' => 'carousel-control-next',
                'data-slide' => 'next',
                'role' => 'button'
            ]);
    } elseif ($this->controls === false) {
        return '';
    } else {
        throw new InvalidConfigException('The "controls" property must be either false or an array of two elements.');
    }
}

            

                public function renderIndicators()
{
    if ($this->showIndicators === false) {
        return '';
    }
    $indicators = [];
    for ($i = 0, $count = count($this->items); $i < $count; $i++) {
        $options = ['data-target' => '#' . $this->options['id'], 'data-slide-to' => $i];
        if ($i === 0) {
            Html::addCssClass($options, ['activate' => 'active']);
        }
        $indicators[] = Html::tag('li', '', $options);
    }
    return Html::tag('ol', implode("\n", $indicators), ['class' => ['carousel-indicators']]);
}

            

                public function renderItem($item, $index)
{
    if (is_string($item)) {
        $content = $item;
        $caption = null;
        $options = [];
    } elseif (isset($item['content'])) {
        $content = $item['content'];
        $caption = ArrayHelper::getValue($item, 'caption');
        if ($caption !== null) {
            $captionOptions = ArrayHelper::remove($item, 'captionOptions', []);
            Html::addCssClass($captionOptions, ['widget' => 'carousel-caption']);
            $caption = Html::tag('div', $caption, $captionOptions);
        }
        $options = ArrayHelper::getValue($item, 'options', []);
    } else {
        throw new InvalidConfigException('The "content" option is required.');
    }
    Html::addCssClass($options, ['widget' => 'carousel-item']);
    if ($index === 0) {
        Html::addCssClass($options, ['activate' => 'active']);
    }
    return Html::tag('div', $content . "\n" . $caption, $options);
}

            

                public function renderItems()
{
    $items = [];
    for ($i = 0, $count = count($this->items); $i < $count; $i++) {
        $items[] = $this->renderItem($this->items[$i], $i);
    }
    return Html::tag('div', implode("\n", $items), ['class' => 'carousel-inner']);
}

            

                public function run()
{
    $this->registerPlugin('carousel');
    return implode("\n", [
            Html::beginTag('div', $this->options),
            $this->renderIndicators(),
            $this->renderItems(),
            $this->renderControls(),
            Html::endTag('div')
        ]) . "\n";
}