minor #12179 Add a note for preload asset (Antoine Lamirault)

OskarStark · OskarStark · commit 9345cd3056e4 · 2019-08-16T07:52:31.000+02:00
This PR was merged into the 3.4 branch. Discussion ---------- Add a note for preload asset This PR add a note about how to preload asset in Sf 3.4. Indeed it was not explained. There was just a symfony blog article about it : https://symfony.com/blog/new-in-symfony-3-3-asset-preloading-with-http-2-push Moreover `preload('build/style.css', { as: 'style' })` generates a good link in Sf4 but not in sf3 (relative instead of absolute). I think is confusing. I hope it can help other developers. Commits ------- d9b88d7 Add a note for preload asset
diff --git a/web_link.rst b/web_link.rst
@@ -69,6 +69,17 @@ If you reload the page, the perceived performance will improve because the
 server responded with both the HTML page and the CSS file when the browser only
 requested the HTML page.
 
+.. note::
+
+    You can preload an asset by wrapping it with the ``preload()`` function
+
+    .. code-block:: html+twig
+
+        <head>
+            {# ... #}
+            <link rel="stylesheet" href="{{ preload(asset('build/app.css')) }}">
+        </head>
+
 Additionally, according to `the Priority Hints specification`_, you can signal
 the priority of the resource to download using the ``importance`` attribute:
 
