action resource

action.rb

# app/models/posts/action.rb
class Action
  include ActiveModel::Model
  
  attr_reader :post_id, :name

  def save
    return false if invalid?

    @post = Post.find(post_id)
    if name == 'publish'
      @post.update state: :publish, published_at: Time.zone.now
    elsif name == 'xxx'
      # do something
    end
    # 適当にif分岐にしてるけど、本当はもう少しクラス設計を直して、if文がなくなるようにした方が良い
  end
end

actions_controller.rb

# app/controllers/posts/actions_controller.rb
module Posts
  class ActionsController < ApplicationController
    # POST /posts/:post_id/actions.json
    def create
      @action = Posts::Action.new(post_id: params[:post_id], name: params[:name])
      
      respond_to do |format|
        if @action.save
          format.json { render json: @action, status: :created }
        else
          format.json { render json: @action.errors, status: :unprocessable_entity }
        else
      end
    end
  end
end