function PathBasedBreadcrumbBuilder::build

Overrides BreadcrumbBuilderInterface::build

File

core/modules/system/src/PathBasedBreadcrumbBuilder.php, line 145

Class

PathBasedBreadcrumbBuilder

Defines a class to build path-based breadcrumbs.

Namespace

Code

public function build(RouteMatchInterface $route_match) {
    $breadcrumb = new Breadcrumb();
    $links = [];
    // Add the url.path.parent cache context. This code ignores the last path
    // part so the result only depends on the path parents.
    $breadcrumb->addCacheContexts([
        'url.path.parent',
        'url.path.is_front',
    ]);
    // Do not display a breadcrumb on the frontpage.
    if ($this->pathMatcher
        ->isFrontPage()) {
        return $breadcrumb;
    }
    // General path-based breadcrumbs. Use the actual request path, prior to
    // resolving path aliases, so the breadcrumb can be defined by simply
    // creating a hierarchy of path aliases.
    $path = trim($this->context
        ->getPathInfo(), '/');
    $path_elements = explode('/', $path);
    $exclude = [];
    // Don't show a link to the front-page path.
    $front = $this->config
        ->get('page.front');
    $exclude[$front] = TRUE;
    // /user is just a redirect, so skip it.
    // @todo Find a better way to deal with /user.
    $exclude['/user'] = TRUE;
    while (count($path_elements) > 1) {
        array_pop($path_elements);
        // Copy the path elements for up-casting.
        $route_request = $this->getRequestForPath('/' . implode('/', $path_elements), $exclude);
        if ($route_request) {
            $route_match = RouteMatch::createFromRequest($route_request);
            $access = $this->accessManager
                ->check($route_match, $this->currentUser, NULL, TRUE);
            // The set of breadcrumb links depends on the access result, so merge
            // the access result's cacheability metadata.
            $breadcrumb = $breadcrumb->addCacheableDependency($access);
            if ($access->isAllowed()) {
                $title = $this->titleResolver
                    ->getTitle($route_request, $route_match->getRouteObject());
                if (!isset($title)) {
                    // Fallback to using the raw path component as the title if the
                    // route is missing a _title or _title_callback attribute.
                    $title = str_replace([
                        '-',
                        '_',
                    ], ' ', Unicode::ucfirst(end($path_elements)));
                }
                $url = Url::fromRouteMatch($route_match);
                $links[] = new Link($title, $url);
            }
        }
    }
    // Add the Home link.
    $links[] = Link::createFromRoute($this->t('Home'), '<front>');
    return $breadcrumb->setLinks(array_reverse($links));
}