src/widget/Breadcrumbs.php
protected function renderItem($link, $template)
    {
        if (isset($link['label'])) {
            $label = $this->encodeLabels ? Html::encode($link['label']) : $link['label'];
        } else {
            throw new InvalidConfigException('The "label" element is required for each link.');
        }
        if($link['options']['class']){
            $label = Html::tag('i', '',$link['options']).$label;
        }
        if (isset($link['url'])) {
            return strtr($template, ['{link}' => Html::a($label, $link['url'])]);
        } else {
            return strtr($template, ['{link}' => $label]);
        }
    }
protected function renderItem($link, $template)
    {
        if (isset($link['label'])) {
            $label = $this->encodeLabels ? Html::encode($link['label']) : $link['label'];
        } else {
            throw new InvalidConfigException('The "label" element is required for each link.');
        }
        if($link['options']['class']){
            $label = Html::tag('i', '',$link['options']).$label;
        }
        if (isset($link['url'])) {
            return strtr($template, ['{link}' => Html::a($label, $link['url'])]);
        } else {
            return strtr($template, ['{link}' => $label]);
        }
    }
Renders a single breadcrumb item.
@param array $link the link to be rendered. It must contain the "label" element. The "url" element is optional.
@param string $template the template to be used to rendered the link. The token "{link}" will be replaced by the link.
@return string the rendering result
@throws InvalidConfigException if `$link` does not have "label" element.