Rails layout not applied when using `render :component`

[leehoworko]

When upgrading from Rails 7.2 to 8, we encountered an issue where controller layouts are no longer applied when using render :component with server-side rendering in react-rails. This document talks about this use case, specifically "By default, your current layout will be used and the component, rather than a view, will be rendered in place of yield."

In Rails 7.2.2.1 with react-rails 2.6.2, everything works as expected. The problem is introduced in Rails 8 due to a change in the render pipeline: the point at which layouts are applied has shifted. Specifically, the component renderer adds an inline key to the render options. In Rails 7.2, the layout was added before this step, so the presence of the inline key didn't affect the layout being applied. In Rails 8, the pipeline was altered so that the component renderer adds the inline key before the layout is applied, which prevents the layout from being included by default.

This is the Rails commit that introduced the change.

[Matchlighter]

Workaround more than a fix, but adding

  def render(*args, **kwargs)
    kwargs[:layout] = 'application' if kwargs[:component] && kwargs[:layout].nil?
    super
  end

to my ApplicationController got me running again without having to add layout: everywhere.