` tag in the HTML `<head>`. Rails lets you do this from another part of the view using the `content_for` feature, but this pattern precludes defining an explicit interface for your layout through its initializer. If layouts are Phlex views, they can be rendered just like any other view and can require that `title` argument from their initializer. The trick is the page view renders its content into the layout view. MD render Example.new do |e| e.tab "layout.rb", <<~RUBY module Views class Layout < Phlex::HTML def initialize(title:) @title = title end def template(&) html do head do title { @title } end body(&) end end end end RUBY e.tab "index.rb", <<~RUBY module Views class Index < Phlex::HTML def template render Layout.new(title: "Hello") do h1 { "👋" } end end end end RUBY e.execute "Views::Index.new.call" end render Markdown.new <<~MD If you're using a Phlex view as a layout, you'll want to disable layouts from your Rails controller. You can do this by adding `layout false` to your controller. In a new app, you'll probably want to add this to the `ApplicationController`. MD end end end end end

# frozen_string_literal: true module Pages module Rails class Layouts < ApplicationPage def template render Layout.new(title: "Getting started with Rails") do render Markdown.new <<~MD # Layouts in Rails Rails has an implicit layouts feature that automatically wraps views in a layout template, usually `views/layouts/application.html.erb`. When using Phlex, you'll probably want to by-pass this feature completely. Here's why: Sometimes you need to pass some argument to the layout, such as a page title that needs to be rendered in a `` tag in the HTML `<head>`. Rails lets you do this from another part of the view using the `content_for` feature, but this pattern precludes defining an explicit interface for your layout through its initializer. If layouts are Phlex views, they can be rendered just like any other view and can require that `title` argument from their initializer. The trick is the page view renders its content into the layout view. MD render Example.new do |e| e.tab "layout.rb", <<~RUBY module Views class Layout < Phlex::HTML def initialize(title:) @title = title end def template(&) html do head do title { @title } end body(&) end end end end RUBY e.tab "index.rb", <<~RUBY module Views class Index < Phlex::HTML def template render Layout.new(title: "Hello") do h1 { "👋" } end end end end RUBY e.execute "Views::Index.new.call" end render Markdown.new <<~MD If you're using a Phlex view as a layout, you'll want to disable layouts from your Rails controller. You can do this by adding `layout false` to your controller. In a new app, you'll probably want to add this to the `ApplicationController`. MD end end end end end