Themeable

You can create theme with this tool, make your Rails app choose theme dynamically.

Install gem

gem i themeable

Create your theme with command line

themeable new my_theme

Now, directory theme_my_theme created with this tool.

Design your theme

Start designing your theme in folder theme:

theme
├── assets
│   └── my_theme
│       ├── application.css
│       └── application.js
├── scaffold_templates
│   ├── admin
│   │   ├── _form.html.erb
│   │   ├── edit.html.erb
│   │   ├── index.html.erb
│   │   ├── new.html.erb
│   │   └── show.html.erb
│   └── default
│       ├── _form.html.erb
│       ├── edit.html.erb
│       ├── index.html.erb
│       ├── new.html.erb
│       └── show.html.erb
└── views
    └── layouts
        └── application.html.erb

• theme/assets/my_theme: where your stylesheets and javascripts should put in
• theme/scaffold_templates/xxx: your scaffold templates, generated default and admin by default, sure you can add more
• theme/views: your views

If you have some vendor scripts and stylesheets, please put them in vendor/my_theme:

vendor
└── my_theme

To require vendor files, do it as this:

in some.js

//= require my_theme/xxx/xxx

in some.css

*= require my_theme/xxx/xxx

Use your theme in your Rails project

Add gem to Rails app:

gem 'theme_my_theme', path: 'path_of_theme_my_theme'

Use theme in controller:

By default you need to remove views/layouts/application.html.erb from Rails app, make sure Rails can use theme's layout.

class HomeController < ApplicationController
  acts_as_themeable 'my_theme'
  def index
  end
end

Or, you can make this controller use dynamic themes:

class HomeController < ApplicationController
  acts_as_themeable :choose_theme
  def index
  end
  
  private
  
  def choose_theme
    case params[:theme]
    when 'my_theme' then 'my_theme'
    when 'classic' then 'classic'
    else; :none # :none means don't use theme
    end
  end
end

Use theme_my_theme as template engine to scaffold controller views

$ rails g scaffold_controller User --template-engine=theme_my_theme --scaffold-template=default
  
    create  app/controllers/users_controller.rb
    invoke  theme_my_theme
    create    app/views/users
    create    app/views/users/index.html.erb
    create    app/views/users/edit.html.erb
    create    app/views/users/show.html.erb
    create    app/views/users/new.html.erb
    create    app/views/users/_form.html.erb
    invoke  test_unit
    create    test/controllers/users_controller_test.rb
    invoke  helper
    create    app/helpers/users_helper.rb
    invoke    test_unit
    invoke  jbuilder
    create    app/views/users/index.json.jbuilder
    create    app/views/users/show.json.jbuilder
    create    app/views/users/_user.json.jbuilder

Customize theme_my_theme in your Rails project

In your Rails project, if you feel theme_my_theme is not perfect, and want to make some changes to it only affect current Rails project, instead of all Rails projects which are using gem theme_my_theme, now you can do this:

$ rails g theme_my_theme:copy_assets

     exist  app/assets/themes
    create  app/assets/themes/my_theme/application.css
    create  app/assets/themes/my_theme/application.js
    
$ rails g theme_my_theme:copy_views
     exist  app/views
 identical  app/views/layouts/.gitkeep
  conflict  app/views/layouts/application.html.erb
Overwrite /test_theme/app/views/layouts/application.html.erb? (enter "h" for help) [Ynaqdh] a
     force  app/views/layouts/application.html.erb
    create  lib/templates/theme_my_theme/scaffold
    create  lib/templates/theme_my_theme/scaffold/admin/_form.html.erb
    create  lib/templates/theme_my_theme/scaffold/admin/edit.html.erb
    create  lib/templates/theme_my_theme/scaffold/admin/index.html.erb
    create  lib/templates/theme_my_theme/scaffold/admin/new.html.erb
    create  lib/templates/theme_my_theme/scaffold/admin/show.html.erb
    create  lib/templates/theme_my_theme/scaffold/default/_form.html.erb
    create  lib/templates/theme_my_theme/scaffold/default/edit.html.erb
    create  lib/templates/theme_my_theme/scaffold/default/index.html.erb
    create  lib/templates/theme_my_theme/scaffold/default/new.html.erb
    create  lib/templates/theme_my_theme/scaffold/default/show.html.erb

Set theme_my_them as default template engine

If you feel each time to generate scaffold controller has to provide --template-engine=theme_my_theme is annoying, now you can set a default value like this:

in config/application.rb, add Themeable.template_engine = :my_theme, note this is :my_theme but :theme_my_theme, this is different from the value of --template-engine

module TestTheme
  class Application < Rails::Application

    ....

    Themeable.template_engine = :my_theme

    ...

  end
end