stimulus_data helper

stimulus_data.rb

# Example Usage
# data: stimulus_data(
#   autosubmit: { controller: true },
#   toggle: { controller: true, classes: { checked: "highlighted", unchecked: "unhighlighted" } },
#   sortable: { target: "sortBy", actions: { click: "sort" },
# ).merge(other: "stuff")

class StimulusData
  def initialize(**controllers)
    @controllers = controllers
  end

  def call
    {
      controller: controller,
      action: action
    }.merge(
      *targets,
      *nested_attributes(:params),
      *nested_attributes(:values),
      *nested_attributes(:classes),
      *nested_attributes(:outlets)
    ).compact_blank
  end

  private

  attr_reader :controllers

  def controller
    controllers.select { |_, value| value[:controller] }.keys.map(&:to_s).map(&:dasherize).join(" ")
  end

  def action
    controllers.select { |_, value| value.has_key?(:actions) }
               .map { |key, value| extract_actions(key, value[:actions]) }
               .join(" ")
  end

  def extract_actions(controller, actions)
    actions.map { |key, value| "#{action_prefix(key)}#{controller.to_s.dasherize}##{value}" }
  end

  def action_prefix(action_key)
    return "" if action_key == :default

    "#{action_key}->"
  end

  def targets
    controllers.select { |_, value| value.has_key?(:target) }
               .map { |key, value| { "#{key}_target".to_sym => value[:target] } }
  end

  def nested_attributes(attribute)
    controllers.select { |_, value| value.has_key?(attribute) }
               .flat_map { |key, value| extract_attributes(key, attribute, value[attribute]) }
  end

  def extract_attributes(controller, attribute, attributes)
    attributes.map { |key, value| { "#{controller}_#{key}_#{attribute.to_s.singularize}".to_sym => value } }
  end
end

stimulus_data_test.rb

require "test_helper"

class StimulusDataTest < ActiveSupport::TestCase
  context "#call" do
    should "return empty hash when input empty" do
      assert_equal({}, StimulusData.new.call)
    end

    should "return hash with proper output" do
      assert_equal(
        { controller: "autosubmit" },
        StimulusData.new(autosubmit: { controller: true }).call
      )

      assert_equal(
        { controller: "auto-submit", action: "input->auto-submit#submit resize@window->auto-submit#cancel" },
        StimulusData.new(auto_submit: { controller: true, actions: { input: "submit", "resize@window": "cancel" } }).call
      )

      assert_equal(
        {
          action: "item#upvote spinner#start", item_id_param: "12345", item_url_param: "/votes",
          item_payload_param: '{"value":"1234567"}', item_active_param: "true"
        },
        StimulusData.new(
          item: { actions: { default: "upvote" }, params: { id: "12345", url: "/votes", payload: '{"value":"1234567"}', active: "true" } },
          spinner: { actions: { default: "start" } }
        ).call
      )

      assert_equal(
        { autosubmit_target: "status" },
        StimulusData.new(autosubmit: { target: "status" }).call
      )

      assert_equal(
        { controller: "tooltip", tooltip_content_value: "usernames…", tooltip_theme_value: "tooltip-sm" },
        StimulusData.new(tooltip: { controller: true, values: { content: "usernames…", theme: "tooltip-sm" } }).call
      )

      assert_equal(
        { controller: "autosubmit checkbox-toggle", checkbox_toggle_checked_class: "highlighted", checkbox_toggle_unchecked_class: "un-highlight" },
        StimulusData.new(autosubmit: { controller: true }, checkbox_toggle: { controller: true, classes: { checked: "highlighted", unchecked: "un-highlight" } }).call
      )

      assert_equal(
        { controller: "chat", chat_user_status_outlet: ".online-user" },
        StimulusData.new(chat: { controller: true, outlets: { user_status: ".online-user" } }).call
      )

      assert_equal(
        { search_target: "projects", checkbox_target: "input" },
        StimulusData.new(search: { target: "projects" }, checkbox: { target: "input" }).call
      )

      assert_equal(
        { controller: "search", search_loading_class: "bg-gray-500 animate-spinner cursor-busy" },
        StimulusData.new(search: { controller: true, classes: { loading: "bg-gray-500 animate-spinner cursor-busy" } }).call
      )

      assert_equal(
        { controller: "search", search_loading_class: "search--busy", search_no_results_class: "search--empty" },
        StimulusData.new(search: { controller: true, classes: { loading: "search--busy", no_results: "search--empty" } }).call
      )
    end
  end
end

stimulus_helper.rb

require 'stimulus_data'

module StimulusHelper
  def stimulus_data(...)
    StimulusData.new(...).call
  end
end