feat: support multiple inertia apps by allowing different layouts (#86)

* feat: support multiple inertia apps by allowing different layouts

* doc: document the intent for `inertia_layout`

Author: ElMassimo

README.md

@@ -73,9 +73,6 @@ InertiaRails.configure do |config|
   # set the current version for automatic asset refreshing. A string value should be used if any.
   config.version = nil
 
-  # set the layout you want inertia components to be rendered within. This layout must include any required inertia javascript.
-  config.layout = 'application'
-
   # ssr specific options
   config.ssr_enabled = false
   config.ssr_url = 'http://localhost:13714'

inertia_rails.gemspec

@@ -34,4 +34,5 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency "sqlite3"
   spec.add_development_dependency "appraisal"
   spec.add_development_dependency "responders"
+  spec.add_development_dependency "debug"
 end

lib/inertia_rails/controller.rb

@@ -38,6 +38,14 @@ def redirect_back(fallback_location:, allow_other_host: true, **options)
 
     private
 
+    def inertia_layout
+      layout = ::InertiaRails.layout
+
+      # When the global configuration is not set, let Rails decide which layout
+      # should be used based on the controller configuration.
+      layout.nil? ? true : layout
+    end
+
     def inertia_location(url)
       headers['X-Inertia-Location'] = url
       head :conflict

lib/inertia_rails/inertia_rails.rb

@@ -62,7 +62,7 @@ def self.lazy(value = nil, &block)
   private
 
   module Configuration
-    mattr_accessor(:layout) { 'application' }
+    mattr_accessor(:layout) { nil }
     mattr_accessor(:version) { nil }
     mattr_accessor(:ssr_enabled) { false }
     mattr_accessor(:ssr_url) { 'http://localhost:13714' }

lib/inertia_rails/renderer.rb

@@ -23,7 +23,7 @@ def render
         @render_method.call json: page, status: @response.status, content_type: Mime[:json]
       else
         return render_ssr if ::InertiaRails.ssr_enabled? rescue nil
-        @render_method.call template: 'inertia', layout: ::InertiaRails.layout, locals: (view_data).merge({page: page})
+        @render_method.call template: 'inertia', layout: layout, locals: (view_data).merge({page: page})
       end
     end
 
@@ -34,7 +34,11 @@ def render_ssr
       res = JSON.parse(Net::HTTP.post(uri, page.to_json, 'Content-Type' => 'application/json').body)
 
       ::InertiaRails.html_headers = res['head']
-      @render_method.call html: res['body'].html_safe, layout: ::InertiaRails.layout, locals: (view_data).merge({page: page})
+      @render_method.call html: res['body'].html_safe, layout: layout, locals: (view_data).merge({page: page})
+    end
+
+    def layout
+      @controller.send(:inertia_layout)
     end
 
     def props

spec/dummy/app/controllers/inertia_test_controller.rb

@@ -1,8 +1,14 @@
 class InertiaTestController < ApplicationController
+  layout 'conditional', only: [:with_different_layout]
+
   def empty_test
     render inertia: 'EmptyTestComponent'
   end
 
+  def with_different_layout
+    render inertia: 'EmptyTestComponent'
+  end
+
   def redirect_test
     redirect_to :empty_test
   end

spec/dummy/app/views/layouts/conditional.html.erb

@@ -0,0 +1,2 @@
+<h1>Conditional layout specified by controller</h1>
+<%= yield %>

spec/dummy/config/routes.rb

@@ -7,6 +7,7 @@
   get 'share' => 'inertia_share_test#share'
   get 'share_with_inherited' => 'inertia_child_share_test#share_with_inherited'
   get 'empty_test' => 'inertia_test#empty_test'
+  get 'with_different_layout' => 'inertia_test#with_different_layout'
   get 'redirect_test' => 'inertia_test#redirect_test'
   get 'inertia_request_test' => 'inertia_test#inertia_request_test'
   get 'inertia_partial_request_test' => 'inertia_test#inertia_partial_request_test'

spec/inertia/configuration_spec.rb

@@ -98,6 +98,27 @@
         it { is_expected.to render_template 'testing' }
         it { is_expected.not_to render_template 'application' }
       end
+
+      context 'opting out of a different layout for Inertia' do
+        before do
+          InertiaRails.configure {|c| c.layout = nil }
+        end
+
+        it 'uses default layout for controller' do
+          get empty_test_path
+          is_expected.to render_template 'inertia'
+          is_expected.to render_template 'application'
+          is_expected.not_to render_template 'testing'
+        end
+
+        it 'applies conditional layouts as needed' do
+          get with_different_layout_path
+          is_expected.to render_template 'inertia'
+          is_expected.to render_template 'conditional'
+          is_expected.not_to render_template 'application'
+          is_expected.not_to render_template 'testing'
+        end
+      end
     end
   end
 end

spec/rails_helper.rb

@@ -3,6 +3,8 @@
 
 require File.expand_path('../dummy/config/environment', __FILE__)
 
+# Allow using `debugger` to debug failing tests.
+require 'debug'
 
 # Prevent database truncation if the environment is production
 abort("The Rails environment is running in production mode!") if Rails.env.production?