Ruby on Rails view component helpers

ComponentHelper.rb

# https://www.innoq.com/en/blog/rails-frontend-components/
#  app/helpers
module ComponentHelper
  def component(name, data: {}, &block)
    render_component("#{name}/#{name}", { data: data }, &block)
  end

  private

  def render_component(name, locals, &block)
    if block_given?
      # using `layout` is a trick to allow passing blocks to partials
      # (cf. http://stackoverflow.com/a/2952056)
      render layout: name, locals: locals, &block
    else
      render partial: name, locals: locals
    end
  end
end

=begin
# For this to work, we've extended `ApplicationController`
to include `append_view_path Rails.root.join("app", "components")`.  
  .
├── app
│   ├── components
│   │   ├── …
│   │   ├── image_gallery
│   │   │   ├── _image_gallery.html.haml
│   │   │   ├── _image_gallery.scss
│   │   │   ├── image_gallery.js
│   │   │   └── image_gallery.yml
│   │   └── …
=end

=begin 
：ruby
  #  _image_gallery.html.haml
  # parameters are passed into the component's template explicitly
  images = data.fetch(:images) # required
  selected_index = data.fetch(:selected_index, 0)

%image-gallery
  %ul
    - images.each_with_index do |image, index|
      %li{ class: index == selected_index ? "is-active" : nil }
        = image_tag image.src, alt: image.alt
=end

# = component :image_gallery, data: { images: @images }

rails-components.rb

# https://api.rubyonrails.org/v6.0/classes/ActionView/PartialRenderer.html
# https://goiabada.blog/rails-components-faedd412ce19