Search engine indexing support

Author: vitkutny

README.md

@@ -58,3 +58,25 @@ services:
 		setup:
 			- Pd\AsyncControl\UI\AsyncControlLink::setDefault('Load content', {class: [btn, ajax]})
 ```
+
+## Search engines
+
+To allow indexing of your site by crawlers you need to add meta tag to your page.
+
+```latte
+<meta name="fragment" content="!" n:if="$presenter->getParameter('_escaped_fragment_') === NULL">
+```
+
+> If you place into the page www.example.com, the crawler will temporarily map this URL to www.example.com?_escaped_fragment_= and will request this from your server. Your server should then return the HTML snapshot corresponding to www.example.com
+
+When parameter `_escaped_fragment_` is present in url `AsyncControlTrait` will always render its content.
+
+If you want the same behaviour for visitors of your page with disabled JS, add additional meta tag within noscript tag:
+
+```latte
+<noscript n:if="$presenter->getParameter('_escaped_fragment_') === NULL">
+	<meta http-equiv="refresh" content="0;url=?_escaped_fragment_="/>
+</noscript>
+```
+
+To avoid extra load on your servers and crawlers use these tags only on pages containing controls with trait `AsyncControlTrait`.

src/UI/AsyncControlTrait.php

@@ -43,7 +43,11 @@ public function handleAsyncLoad()
 
 	public function renderAsync(string $linkMessage = NULL, array $linkAttributes = NULL)
 	{
-		if ($this instanceof Control && strpos((string) $this->getPresenter()->getParameter(Presenter::SIGNAL_KEY), sprintf('%s-', $this->getUniqueId())) !== 0) {
+		if (
+			$this instanceof Control
+			&& $this->getPresenter()->getParameter('_escaped_fragment_') === NULL
+			&& strpos((string) $this->getPresenter()->getParameter(Presenter::SIGNAL_KEY), sprintf('%s-', $this->getUniqueId())) !== 0
+		) {
 			$template = $this->createTemplate();
 			$template->link = new AsyncControlLink($linkMessage, $linkAttributes);
 			$template->setFile(__DIR__ . '/templates/asyncLoadLink.latte');

src/UI/templates/asyncLoadLink.latte

@@ -1,5 +1,5 @@
 <div n:snippet="async">
-	<a n:href="asyncLoad!" n:attr="(expand) $link->getAttributes()" data-async>
+	<a n:href="asyncLoad!" n:attr="(expand) $link->getAttributes()" data-async rel="nofollow">
 		{$link->getMessage()|translate}
 	</a>
 </div>