StimulusReflex Concern-Like Architecture

articles_controller.rb

class ArticlesController < ApplicationController
  def index
    @articles = Article.where(session[:articles][:param] => session[:articles][:value])
  end
end

filterable_reflex.rb

class FilterableReflex < ApplicationReflex
  def filter
    resource, param = element.dataset.to_h.fetch_values(:resource, :param)

    resource_key = resource.pluralize.underscore.to_sym
    session[resource_key][:param] = param
    session[resource_key][:value] = element.value
  end
end

index.html.erb

<%= label_tag "category" %>
<%= select_tag "category",
    options_from_collection_for_select(Category.all, :id, :name)
    data: { action: "change->filterable#filter",
      resource: 'Article',
      param: 'category',
      reflex_root: "#articles" } %>

<div id="articles">
  <%= render @articles %>
</div>