CRAWL динамических страниц для Google и Яндекс поисковиков (snapshots, _escaped_fragment_, ajax, fragment)

Гугл уже умеет JS:

«We are no longer recommending the AJAX crawling proposal we made back in 2009.

In 2009, we made a proposal to make AJAX pages crawlable. Back then, our systems were not able to render and understand pages that use JavaScript to present content to users. Because «crawlers … [were] not able to see any content … created dynamically,» we proposed a set of practices that webmasters can follow in order to ensure that their AJAX-based applications are indexed by search engines.

Times have changed. Today, as long as you're not blocking Googlebot from crawling your JavaScript or CSS files, we are generally able to render and understand your web pages like modern browsers. To reflect this improvement, we recently updated our technical Webmaster Guidelines to recommend against disallowing Googlebot from crawling your site's CSS or JS files.»

https://webmasters.googleblog.com/2015/10/deprecating-our-ajax-crawling-scheme.html

if (isset($_GET['_escaped_fragment_'])) {
    if ($_GET['_escaped_fragment_'] != ''){
        $val = $_GET['_escaped_fragment_'];
        include_once "snapshots" . $val . '/index.html';
    }else{
        $url = "https://" . $_SERVER["HTTP_HOST"] . $_SERVER["REQUEST_URI"];
        $arrUrl = parse_url($url);
        $val = $arrUrl['path'];
        include_once "snapshots" . $val . '/index.html';
    }

Отдавать статичный html через php, да еще через include — то еще извращение.
Пусть этим занимается nginx:

location / {
if ( $args ~ "_escaped_fragment_=(.+)" ) {
  set $real_url $1;
  rewrite ^ /snapshots/$real_url.html? break;
  }
try_files $uri $uri/ =404;
}