resources_controller.rb

module ResourcesController
  
  extend ActiveSupport::Concern
  
  def index
    render json: resources
  end
  
  def show
    render json: resource
  end
  
  def create
    if update_resource
      render json: resource
    else
      render json: resource.errors, status: 422
    end
  end
  
  def update
    if update_resource
      render json: resource
    else
      render json: resource.errors, status: 422
    end
  end
  
  def destroy
    if soft_deletable?
      resource.deleted_at = Time.now
      resource.save
      
      render json: { id: resource.id }
    else
      render json: { id: resource.id }, status: :forbidden
    end
  end

  protected
  
  def update_resource
    resource.save
  end
  
  def resource_class
    self.class.resource_class
  end
  
  def resources
    if soft_deletable?
      resources_with_deleted.where(deleted_at: nil)
    else
      resources_with_deleted
    end
  end
  
  def resources_with_deleted
    resource_class
  end
  
  def resource
    @resource ||= begin
      if id = params[:id]
        resources.find(id) or raise MongoMapper::DocumentNotFound
      else
        build_resource
      end
    end
  end
  
  def build_resource
    resources.new
  end
  
  def soft_deletable?
    false
  end
  
  module ClassMethods
    def resource_class
      @resource_class ||= name.sub(/Controller$/, '').tableize.singularize.classify.demodulize.constantize
    end
  end

end