How to Generate sitemap in laravel

Route::get('sitemap-store', function()
{
    // create sitemap
    $sitemap_posts = App::make("sitemap");

    // add items
    $posts = DB::table('posts')->orderBy('created_at', 'desc')->get();
    foreach ($posts as $post)
    {
        $sitemap_posts->add($post->slug, $post->modified, $post->priority, $post->freq);
    }

    // create file sitemap-posts.xml in your public folder (format, filename)
    $sitemap_posts->store('xml','sitemap-posts');

    // create sitemap
    $sitemap_tags = App::make("sitemap");

    // add items
    $tags = DB::table('tags')->get();

    foreach ($tags as $tag)
    {
        $sitemap-tags->add($tag->slug, null, '0.5', 'weekly');
    }

    // create file sitemap-tags.xml in your public folder (format, filename)
    $sitemap_tags->store('xml','sitemap-tags');

    // create sitemap index
    $sitemap = App::make ("sitemap");

    // add sitemaps (loc, lastmod (optional))
    $sitemap->addSitemap(URL::to('sitemap-posts'));
    $sitemap->addSitemap(URL::to('sitemap-tags'));

    // create file sitemap.xml in your public folder (format, filename)
    $sitemap->store('sitemapindex','sitemap');
});