Pass in a block to render_async
You can now pass in a block that will act as a placeholder.
If you want to add some feedback before your AJAX request is finished, passing a block is the way.
Example:
<%= render_async movie_path do %>
<div class="cool-spinner"></div>
<% end %>
Now you will have the spinner (or anything you like) show before AJAX call finishes.
BREAKING_CHANGE:
This is a breaking change for those who relied on the <div>
elements that we're rendered before
AJAX call.
Mentioned div element:
<div class="sk-spinner sk-spinner-double-bounce">
<div class="sk-double-bounce1"></div>
<div class="sk-double-bounce2"></div>
</div>
Those elements were there for spinner purposes but are removed from this version.