In the template:

<title><%= title(assigns) %></title>

In the view module of the template:

def title(assigns) do
  module = Phoenix.Controller.view_module(assigns.conn)
  template = Phoenix.Controller.view_template(assigns.conn)
  module.title(template, assigns)
end

There’s no need to keep all that logic in the template itself.

Those functions have been moved to Phoenix.Controller.view_module/view_template. The reason is because those concepts are not very clear (or very useful) in some abstractions like LiveView, so we realized it belongs upstream. I believe it was properly deprecated and there should be CHANGELOG entries. If you are not rendering from the controller, then you have to set it yourself.

Thanks. I wish I understood better, it still seems quite strange to me that an explicit call to Phoenix.View.render wouldn’t pass along the relevant information to the layout, and this seems quite remote from LiveView.

I opened Change wording on Changelog by marcandre · Pull Request #4571 · phoenixframework/phoenix · GitHub as the only reference in the Changelog was as a deprecation when this is actually a breaking change.

The upgrade guide is sadly a gist, so no PR possible. Could we consider moving it to the repo?