mapknitter/app/controllers/feeds_controller.rb

class FeedsController < ApplicationController
  before_action :query, only: %i(clean license)

  def all
    # (Warpable.all + Map.all).sort_by(&:created_at)
    @maps = Map.where(archived: false, password: '')
               .joins(%i(user warpables))
               .group('maps.id')
               .order('id DESC')
               .limit(20)
    render layout: false, template: 'feeds/all'
    response.headers['Content-Type'] = 'application/xml; charset=utf-8'
  end

  def clean
    render layout: false, template: 'feeds/clean'
    response.headers['Content-Type'] = 'application/xml; charset=utf-8'
  end

  def license
    @maps = @maps.where(license: params[:id])
    render layout: false, template: 'feeds/license'
    response.headers['Content-Type'] = 'application/xml; charset=utf-8'
  end

  def author
    @maps = Map.where(author: params[:id], archived: false, password: '')
               .order('id DESC')
               .joins(:warpables)
               .group('maps.id')
    images = []
    @maps.each do |map|
      images += map.warpables
    end
    @feed = (@maps + images).sort_by(&:created_at)
    render layout: false, template: 'feeds/author'
    response.headers['Content-Type'] = 'application/xml; charset=utf-8'
  end

  def tag
    @tag = Tag.find_by_name params[:id]
    @maps = @tag.maps.paginate(page: params[:page], per_page: 24)
    render layout: false, template: 'feeds/tag'
    response.headers['Content-Type'] = 'application/xml; charset=utf-8'
  rescue NoMethodError
    render plain: "No maps with tag #{params[:id]}"
  end

  private

  def query
    @maps = Map.order(id: :desc)
               .limit(20)
               .where(archived: false, password: '')
               .joins(:warpables)
               .group('maps.id')
  end
end